WO1992010501A1 - Herbicidal ethers - Google Patents

Abstract

This invention relates to certain herbicidal ethers, of formulas I-V, agriculturally suitable compositions thereof, and a method for their use as broad spectrum preemergent or postemergent herbicides.

Description

TITLE

HERBICIDAL ETHERS BACKGROUND OF THE INVENTION

This invention relates to certain herbicidal ethers, agriculturally suitable compositions thereof, and a method for their use as broad spectrum preemergent or postemergent herbicides.

New compounds effective for controlling the growth of undesired vegetation are in constant demand. In the most common situation, such compounds are sought to selectively control the growth of weeds in useful crops such as cotton, rice, corn, wheat and soybeans, to name a few. Unchecked weed growth in such crops can cause significant losses, reducing profit to the farmer and increasing costs to the consumer. In other situations, herbicides are desired which will control all plant growth. Examples of areas in which complete control of all vegetation is desired are areas around railroad tracks, storage tanks and industrial storage areas.

There are many products commercially available for these purposes, but the search continues for products which are more effective, less costly and environmentally safe.

U.S. Patent 4,670,041 discloses a variety of

herbicidal cyclic ethers of the formula

wherein, inter alia

R₃ is hydrogen atom or an alkyl group containing from 1 to 10 carbon atoms; a cyano group; an alkyl group substituted by: a hydroxy group, a cyano group, an alkoxy group containing from 1 to 6 carbon atoms, a C_1-6 alkylsulfonyl group, a C_6-10 arylsulfonyl group, a C_7-11 aralkysulfonyl group, an azido group, a C_1-6 alkoxycarbonyl group, a hydroxycarbonyl group, a dialkoxyphosphonge[sic] group or an amine oxide, carbamoyl or

thiocarbamoyl group, each nitrogen atom

substituted by hydrogen or by 1 or 2 alkyl groups containing from 1 to 4 carbon atoms; or R₃ is an alkenyl or alkynyl group containing 2 to 4 carbon atoms; an aryl or aralkyl group, each containing from 6 to 11 carbon atoms including 1 to 4 carbon atoms in the alkyl portion and optionally ring substituted by halogen or by an alkyl or alkoxy group containing from 1 to 2 carbon atoms, each optionally substituted by one or more halogen atoms, or R₃ is a group-CO₂R₈; -CON(R₈)₂, or -CSNH₂ in which R₃ is a hydrogen atom or an alkyl group containing from 1 to 6 carbon atoms; or R₃ is an acyl group containing 1 to 6 carbon atoms or an oxime or an acetal derivative of said acyl group. SUMMERY OF THE INVENTION

This invention comprises compounds of Formulas I, II, III, IV and V including stereoisomers, agriculturally suitable compositions containing them, and their

method-of-use as broad spectrum preemergent and

postemergent herbicides.

wherein

X¹ is OR⁹, CO₂R¹¹, C(O)R¹¹, CHO, C(O)NR¹²R¹³, SH,

S(O)_nR¹⁵, SO₂NR¹²R¹³, SO₂N(OCH₃) (CH₃), NHR¹⁶, NR¹⁶R¹⁷, CH=NOR¹⁴, C (R¹¹)=NOR¹⁴ or CR⁴R⁵Y;

X² is CO₂R¹¹, C(O)R¹¹, CHO, C(O)NR¹²R¹³, S(O)_nR¹⁵, SO₂NR¹²R¹³, SO₂N(OCH₃) (CH₃), CH=NOR¹⁴,

C(R¹¹)=NOR¹⁴ or CR⁴R⁵Y;

Y is OR¹⁸, CO₂R¹⁹, C(O)R¹⁹, CHO, C(O)NR²⁰R²¹, SH,

S(O)_nR²², SO₂NR²⁰R²¹, SO₂N (OCH3MCH3), NHR²³,

NR²³R²⁴, P(O)(OR²⁹)₂, CH=NOR²⁵ or C (R¹¹)=NOR²⁵; n is 0, 1 or 2;

R¹ is H or a straight chain C₁-C₃ alkyl;

R² and R⁴ are independently H, C₁-C₃ alkyl,

C₁-C₃ alkoxy or halogen;

R³ and R⁵ are independently H or C₁-C₃ alkyl;

R² and R³ may be taken together to form a 3- to

5-membered ring;

R⁴ and R⁵ may be taken together to form a 3- to

5-membered ring;

R⁶ is H or C₁-C₄ alkyl;

R⁷ and R⁸ are independently H, C₁-C₄ alkyl,

C₂-C₄ alkenyl, C₂-C₄ alkynyl or C₁-C₃ alkyl substituted with OCH₃ or OCH₂CH₃;

R⁹ and R¹⁸ are independently H, C₁-C₆ alkyl

optionally substituted with halogen, C₁-C₂ alkoxy, CN or CO₂CH₃; C₃-C₆ alkenyl optionally substituted with halogen or C1-C2 alkoxy; C₃-C₆ alkynyl; SO₂R¹⁰; C(O)NR¹²R¹³; P(O)(R¹⁶)₂;

P(O)(OR¹⁶)2; or benzyl;

R¹⁰ is C₁-C₄ alkyl optionally substituted with

halogen; or allyl;

R¹¹ and R¹⁹ are independently C₁-C₄ alkyl optionally substituted with C1-C2 alkoxy, C₁-C₂ alkylthio, halogen or NR¹²R¹³; C₃-C₄ alkenyl; C₃-C₄ alkynyl; CH₂-cyclopropyl; or cyclobutyl;

R¹² and R¹³, are independently H, C₁-C₃ alkyl or may be taken together to form a 4- to 6-mem-bered ring;

R²⁰ and R²¹ are independently H, C₁-C₃ alkyl or may be taken together to form a 4- to 6-mem-bered ring;

R¹⁴ and R²⁵ are independently H, C₁-C₃ alkyl or

allyl;

R¹⁵ and R²² are independently C₁-C₄ alkyl; R¹⁶, R¹⁷, R²⁴ and R²⁹ are independently C₁-C₃ alkyl; R²³ is C₁-C₃ alkyl, C(O)(C₁-C₂ alkyl), SO₂ <C₁-C₂

alkyl), C(O)NHCH₃ or C(O)N(CH₃)₂;

Q is CH₂W or

R²⁶ is H, halogen, C₁-C₃ alkyl, OR²⁷, SR²⁷ or CN; R²⁷ is C₁-C₃ alkyl or C₁-C₃ haloalkyl;

Z is CH₂, NR²⁸, O, S or may be CH and taken to form a double bond with an adjacent carbon;

R²⁸ is H or C₁-C₃ alkyl;

q is 0, 1 or 2;

r is 0, 1 or 2; and

W is phenyl optionally substituted with 1-3

substituents selected from halogen, C₁-C₃ alkyl, C₁-C₃ alkoxy, OH, CN, C₁-C₃ haloalkyl, C₁-C₃ haloalkoxy, C₁-C₃ alkylthio, C2-C4 alkenyl and C₂-C₄ alkynyl, or W is 5-, 6- or 7-membered heterocyclic ring containing one or more

heteroatoms selected from the group 0-2

nitrogens, 0-2 oxygens and 0-2 sulfurs, each ring optionally substituted with 1-2 substituents selected from halogen, CH₃ and OCH₃;

provided that

1) the sum of q and r is 0-2;

2) if the sum of q and r is O then Z is CH2;

3) in compounds of Formula I when R¹, R² and R³ are CH₃ and W is phenyl, then X¹ is other than

C(O)NH₂, O(C₁-C₂ alkyl), O(i-propyl), OH or SO₂CH₃; 4) in compounds of Formula I when R¹, R² and R³ are CH₃ and W is 2F-phenyl or 3CF₃-phenyl, then X¹ is other than CO₂CH₃; and

5) in compounds of Formula I when R¹, R² and R³ are CH₃ and W is 2F-phenyl, then X¹ is other than

C(O)N(CH₃)₂.

In the above definitions, the term "alkyl", used either alone or in compound words such as "alkylthio" or "haloalkyl" includes straight chain or branched alkyl, e.g., methyl, ethyl, n-propyl, isopropyl or the different butyl isomers. Alkoxy includes methoxy, ethoxy,

n-propyloxy or isopropyloxy. Alkenyl includes straight chain or branched alkenes, e.g., 1-propenyl, 2-propenyl, 3-propenyl and the different butenyl isomers. Alkylthio, etc. are used analogously to the above examples. The term "halogen", either alone or in compound words such as "haloalkyl", means fluorine, chlorine, bromine or iodine. Further, when used in compound words such as "haloalkyl" said alkyl may be partially or fully substituted with halogen atoms, which may be the same or different.

Examples of haloalkyl include CH₂CH₂F, CF₂CF₃ and

CH₂CHFCI. Representative exemplifications of

heterocycles includes but is not limited to pyrrole, furan, thiophene, tetrahydrofuran, tetrahydropyran, isoxazole, oxazole, pyrazole, imidazole, thiazole,

pyridine and pyrazines.

Compounds of the invention preferred for their biological activity and/or ease of synthesis are:

1) Compounds of Formulas I, II, III, IV and V wherein:

Q is CH₂W or

or

W is phenyl, tetrahydropyran, tetrahydrofuran,

thiophene, isoxazole, pyridine or pyrazine, each ring optionally substituted with 1-2 substituents selected from halogen, CH₃ and OCH₃;

2) Compounds of Preferred 1 wherein

X¹ is OR⁹, CO₂R¹¹, C(O)R¹¹, CHO, C(O)NR¹²R¹³, SH,

CH=NOR¹⁴,C(R¹¹)=NOR¹⁴ or CR⁴R⁵Y;

X² is CO₂R¹¹, C(O)R¹¹, CHO, C(O)NR¹²R¹³, CH=NOR¹⁴,

C(R¹¹)=NOR¹⁴ or CR⁴R⁵Y; R⁹ is H, C₁-C₃ alkyl, allyl, propargyl or SO2CH3; R¹¹ is C₁-C₃ alkyl or allyl;

R¹² is H or CH₃;

R¹³ is CH₃;

R¹⁸ is H, C₁-C₃ alkyl, allyl, propargyl or SO₂ (C₁-C₃ alkyl);

R²² is C₁-C₂ alkyl;

R²⁹ is CH₃;

3) Compounds of Preferred 2 wherein

R¹ is C₁-C₂ alkyl;

R² and R⁴ are independently H, F, Cl, C₁-C₂ alkyl or

OCH₃;

R³ and R⁵ are independently H or C₁-C₂ alkyl;

R⁶ is H or C₁-C₂ alkyl;

R⁷ and R⁸ are independently H or C₁-C₂ alkyl.

4) Compounds of Preferred 3 wherein

Q is CH₂W;

W is phenyl optionally substituted by 1-2

substituents selected from halogen and CH₃;

tetrahydropyran; tetrahydrofuran; thiophene optionally substituted with Cl or Br; or pyridine. 5) Compounds of Preferred 4 wherein

X¹ and X² are independently CO₂(C₁-C₃ alkyl),

CO₂-allyl,

C(O) (C₁-C₃ alkyl) or CR⁴R⁵Y;

Y is O(C₁-C₂ alkyl), OSO₂CH₃ or O-propargyl;

R² and R⁴ are indepedently H, Cl or CH3;

6) Compounds of Preferred 2 wherein

X¹ is OR⁹ or CR⁴R⁵Y;

R⁹ is allyl, propargyl or SO₂CH₃; Y is OR¹⁸, CO₂R¹⁹, C(O)R¹⁹, CHO, SH, SR²², S(O)R²², SO₂NR²⁰R²¹, SO₂N(OCH₃) (CH₃), NHR²³, NR²³R²⁴, P(O)(OR²⁹)₂, CH=NOR²⁵ or C(R⁴)=NOR²⁵;

R¹⁸ is allyl, propargyl or SO₂ (C₁-C₃ alkyl);

R¹⁹ is C₁-C₄ alkyl substituted with C₁-C₂ alkoxy, C₁-C₂ alkylthio, halogen or NR¹²R¹³; C₃-C₄ alkenyl; C₃-C₄ alkynyl; CH2~cyclopropyl; or cyclobutyl;

R²² is C₁-C₂ alkyl;

R²⁹ is CH₃;

7) Compounds of Preferred 6 wherein

R¹ is C₁-C₂ alkyl;

R² and R⁴ are independently H, Cl, C₁-C₂ alkyl or OCH₃;

R³ and R⁵ are independently H or C₁-C₂ alkyl;

R⁶ is H or C₁-C₂ alkyl;

R⁷ and R⁸ are independently H or C₁-C₃ alkyl. 8) Compounds of Preferred 7 wherein

Q is CH₂W;

W is phenyl optionally substituted by 1-2

substituents selected from halogen and CH₃;

tetrahydropyran; tetrahydrofuran; thiophene optionally substituted with Cl or Br; or pyridine.

9) Compounds of Preferred 8 wherein

X¹ and X² are CR⁴R⁵Y;

Y is OR¹⁸;

R² and R⁴ are indepedently H, Cl or CH₃;

R³ and R⁵ are independently H or CH₃;

R¹⁸ is propargyl or SO₂CH₃. 10) Compounds of Preferred 9 wherein the compound is a compound of Formula I.

11) Compounds of Preferred 9 wherein the compound is a compound of Formula II.

12) Compounds of Preferred 9 wherein the compound is a compound of Formula III. 13) Compounds of Preferred 9 wherein the compound is a compound of Formula IV.

14) Compounds of Preferred 9 wherein the compound is a compound of Formula V.

15) Compounds of Preferred 5 wherein the compound is a compound of Formula I.

16) Compounds of Preferred 5 wherein the compound is a compound of Formula II.

17) Compoundds of Preferred 5 wherein the compound is a compound of Formula III. 18) Compounds of Preferred 5 wherein the compound is a compound of Formula IV.

19) Compounds of Preferred 5 wherein the compound is a compound of Formula V. Compounds of the invention specifically preferred for their biological activity and/or ease of synthesis are the compounds of Preferred 15 which are: • methyl exo-4-ethyl-α, α-dimethyl-3- (phenylmethoxy) -7-oxabicyclo [2 .2 .1 ] heptane-1-acetate;

• methyl exo-4-ethyl-3-[(2-fluorophenyl)-methoxy]- α,α-dimethyl-7-oxabicyclo[2.2.1]-heptane-1- acetate;

• methyl (exo)-4-ethy-α-methyl-3-(phenylmethoxy)-7- oxabicyclo-[2.2.1]heptane-1-acetate;

• (exo)-1-ethyl-4-(2-methoxy-1,1-dimethylbutyl)-2- (phenylmethoxy)-7-oxabicyclo[2.2.1]heptane;

• propyl (exo)-4-ethyl-3-[(2-fluorophenyl)methoxyl- α,α-dimethyl-7-oxabicyclo[2.2.1]heptane-1- acetate;

• methyl (exo)-α-chloro-4-ethyl-3-[(2-fluorophenyl)methoxy]-α-methyl-7- oxabicyclo[2.2.1]heptane-1-acetate;

• ethyl (exo)-3-[2,6-difluorophenyl)methoxy]-4- ethyl-α,α-dimethyl-7-oxabicyclo[2.2.1]heptane-1- acetate;

• 2-propenyl (exo)-4-ethyl-α,α-dimethyl-3-(phenylmethoxy)-7-oxabicyclo[2.2.1]]heptane-1-acetate; and

• (exo)-4-[1,1-dimethyl-2-[(2-propynyl)oxy]ethyl]- 1-ethyl-2-[(2-fluorophenyl)methoxy]-7-oxabicyclo[2.2.1]heptane; Compounds of Formula I-V that have the WCH₂O group syn with respect to the oxygen-containing bridge are usually more herbicidally active than the anti form. The present invention contemplates all of the herbicidally active forms resulting from synthesis and from

deliberately created mixtures.

The compositions of the invention are also suitable for controlling the growth of undesired vegetation. Such compositions comprise an effective amount of any of the compounds disclosed herein and at least one of the following: surfactant, solid, or liquid diluent.

Methods for controlling the growth of undesired vegetation by using the compounds of compositions of the invention are similarly considered to be within the scope of the invention. These methods comprise applying to the locus to be protected an effective amount of any of the compounds disclosed herein. Of particular importance is the method wherein the locus to be protected is rice.

DETAILED DESCRIPTION OF THE INVENTION

The compounds of the invention are prepared by treating the appropriately substituted oxabicycloalkanol (Ia-Va or I-V wherein Q is H) with a compound of the formula WCH₂X in which X is a halogen atom or a mesyloxy, tosyloxy group or the like. This reaction is carried out, as shown in Scheme 1, in the presence of a strong base, such as an alkali metal hydride or an alkali metal alkoxide, in an inert solvent, such as ethers, aromatic hydrocarbons, dimethylformamide and the like. Suitable temperatures for the reaction are preferably from -10°C to 100°C. The product ethers are recovered and isolated by conventional techniques.

SCHEME 1

The alkylating agents WCH₂X are prepared in

conventional manners known to those skilled in the art from the alcohols WCH₂OH.

The alcohols, WCH₂OH, are generally known in the art and are most conveniently prepared through metal hydride (e.g., sodium borohydride) reduction of the corresponding ketones which can be derived by Friedel-Crafts type cyclization of derivatives of phenylalkyl-carboxylic acid, phenoxyalkylcarboxylic acids,

phenylthioalkylcarboxylic acids, benzyloxyalkylcarboxylic acids, and benzylthioalkylcarboxylic acids. Details may be found in a) T. Laird in Comprehensive

Organic Chemistry, D. Barton and W. D. Ollis, ed., Vol.

1, pp. 1165-1168, Pergamon Press, New York (1979); b) M.H. Palmer and N. M. Scollick, J. Chem. Soc., C.,

(1968), 2833; c) C. E. Dalgliesch and Mann, J. Chem.

Soc., (1945), 893; d) C. D. Hurd and S. Hayao, J. Am.

Chem. Soc., (1954), 76, 4299 and 5056; and e) R.Lesser, Chem. Ber., (1923), 56, 1642.

Alternatively, the compounds of Formulas I-V may be prepared by the coupling procedure described in Scheme 2, which is used in cases where the standard Williamson ether synthesis proves problematic. This procedure uses a Lewis acidic metal oxide wherein the metal can remove the halide ion by forming an insoluble precipitate. For example, silver (I) oxide can be used and the silver halide is the co-product. Alternative metal oxides that may be used are HgO, CaO, MgO. N,N-Dimethylformamide and ethereal solvents, such as diethyl ether,

tetrahydrofuran, dioxane, or 1,2-dimethoxyethane are the preferred solvents. Other solvents likely to provide good yields include dipolar aprotic solvents such as dimethyl sulfoxide, acetone and N,N'-dimethylpropylene- urea. SCHEME 2

The oxabicycloalkanols (Ia-Va) can be obtained generally by epoxidation-cyclization of unsaturated cyclic alcohols, with or without isolation of the epoxy alcohol intermediates.

Non-limiting illustrations of the preparation of representative compounds are described hereinafter.

The compounds of Formula la are synthesized through the sequence shown in Scheme 3, which begins with the Birch reduction of the appropriate aromatic substrate which provides the non-conjugated ketone (1) after mild acidic hydrolysis (see H. L. Dryden et al., J. Org.

Chem., Vol. 26 (1961), 3237 and references therein).

Addition of a variety of α-stabilized anions to the ketone (1) can provide an olefinic alcohol (2) (see Stowell, J. C, "Carbanions in Organic Synthesis", 1979, Wiley, p. 151 and references therein). The olefin (2) is then oxidized to the epoxide which is opened in situ to form the bicyclic alcohol Ia. The stereochemical

relationship between the newly formed alcohol and the bridging oxygen may be adjusted by using the appropriate epoxidation condition (see K. B. Sharpless et al., J. Am. Chem. Soc, (1973) 95, 6136). Coupling with the

appropriate halide would generate the compound of Formula I. The analogs of I wherein X¹ = (CR⁴R⁵Y) can be

synthesized from I (X¹ = CO₂R¹¹) by treating the ester group with a hydride reducing agent such as lithium aluminum hydride or with a Grignard or alkyllithium reagent (or similar substrate) to provide an alcohol. This alcohol may be endcapped with a variety of reagents (such as alkyl halides R⁹Hal or R¹⁸Hal under Williamson ether synthesis conditions already mentioned wherein R⁹ and R¹⁸ are appropriately selected alkyl groups and Hal is Cl, Br or I) to provide a variety of compounds which also are described by Formula I.

An alternative coupling procedure utilizes a benzyl trichloroacetimidate. This is done in the presence of a Lewis or protic acid (J. Chem. Soc. Chem. Comm. (1981), 1290) . This procedure may be used in cases wherein the base induced procedure results in low yields,

SCHEME 3

As shown in Scheme 3a, in those cases wherein χ¹=P(O)(OR²⁹)₂, recourse to a similar sequence as described in Scheme 3 may be used (see S. Warren et al., Tetrahedron Lett. (1984), 357 for a discussion of the addition of lithiomethylphosphine oxides to aldehydes and P. Savignac et al. Synthesis (1982), 725 for a

description of the generation of α-anions of alkylphosphonates). The metallation of alkylalkane-sulfonates is well precedented (W. E. Truce et al.,

J. Org. Chem. (1970), 1226; J. M. Hawkins et al.,

Tetrahedron Lett. (1990), 981) and similar metallation of the corresponding sulfonamides to form (2) (where

χ¹=SO₂NR¹²R¹³ or SO₂N(OCH₃)(CH₃), etc.) could be possible to finally generate the desired product of Formula I in subsequent steps.

SCHEME 3a

The compounds of Formula I wherein X¹=CHO, CH=NOR¹⁴, C(O)R¹¹ or CR¹¹=NOR¹⁴ can be synthesized from

intermediate I (Y=OH, R⁴=R⁵=H) in Scheme 3. This

sequence is illustrated in Scheme 3b. An oxidation of the primary alcohol to an aldehyde may be carried out using a variety of procedures well known in the art to provide I (X¹=CHO). The ketone I (X¹=C(O)R¹¹) may be synthesized via Grignard addition to the aldehyde

previously described followed by oxidation as already described to provide the corresponding ketone. An

aldoxime or ketoxime may be synthesized from the aldehyde or ketone respectively using a variety of standard oximation procedures .

SCHEME 3b

Branched chain compounds, wherein R⁴=C₁-C₃ alkyl, while R⁵=H may be synthesized from I (X¹=CHO) by Grignard addition followed by capping of the secondary alcohol as already described.

Alternate synthesis of compounds wherein X¹=CR⁴R⁵Y; Y=S(O)_nR²², CO₂R¹⁹, C(O)R¹⁹, etc. is described in Scheme 3c.

SCHEME 3c

This synthesis begins with the conversion of the alcohol I (Y=OH) into the corresponding bromide using a standard bromination procedure followed by the generation of a Grignard or lithium reagent. The alkyl metal reagent thus generated may be quenched with a wide variety of electrophiles according to well known

transformations of Grignard and alkyllithium reagents, thus providing a generalized access to this family of compounds.

The oxabicyclic alcohols of Formula Ila can be synthesized via the synthetic sequence shown beginning with Scheme 4. Diels-Alder cycloaddition of a

substituted alkyl vinyl ketone with an appropriate diene provides a regioisomeric mixture of enones (3a) and (3b) (see Y. A. Titov, Russ. Chem. Rev., (1962), Vol. 31, 267 for a discussion of regiochemistry; H. L. Holmes, Org. Reactions, (1948), Vol. 4, 60). After separation by flash column chromatography or distillation, (3a) is useful to generate compounds of Formula II, while (3b) is useful for similar elaboration to form compounds of Formula IV. The keto group of (3a) is treated with trimethyl sulfoxonium methylide to form epoxide (4a) (see Ind. J. Chem.. Vol. 17B, (1979), 171 for procedure) .

This epoxide is opened with aqueous acid followed by a selective protection of the primary alcohol with a group such as trialkylsilyl (in the example below) or an ester group (see Greene, T., Protective Groups in Organic

Synthesis, Wiley Interscience. New York, 1981). The olefin is then oxidized to the epoxide with a peracid such as peracetic or m-chloroperoxybenzoic acid (L. A. Paquette, Org. Syn., (1969), Vol. 49, 62). The epoxide may be isolated or it may be allowed to react further so that the closed ring system II is formed. These

conditions provide primarily the stereoisomer wherein the alcohol is anti to the bridging oxygen designated

structure Ila. If the syn alcohol is desired, one route to this end is to oxidize Ila (anti) to the ketone (5a) by a variety of methods such as that of Swern (Swern, D., Synthesis, (1981), 165) or Jones (see Bruce, W. F., Org. Synthesis, Coll. Vol. II, 139) followed by selective reduction with a reducing agent such as sodium

borohydride to provide the required alcohol. The

following reactions may be applied to either the anti alcohol Ila or the syn alcohol. Coupling under the above mentioned conditions followed by deprotection of the primary alcohol provide alcohol II (X²=CH₂OH). This material may be oxidized to form the acid using, for example, the Jones procedure, followed by an

esterification. This alternative provides II

(X²=CO₂R¹¹). Alternatively, the alcohol may be capped with base and R¹⁸-Hal to provide II (X=CH₂OR¹⁸).

In a similar manner, (3b) may be elaborated through identical steps to compounds of Formula IV.

The oxabicyclic alcohols of Formula IIIa can be synthesized via the synthetic sequence shown beginning with Scheme 5. Diels-Alder cycloaddition of acrylic acid with the appropriate diene gives a mixture of 2

regioisomers (6a) and (6b). After separation by

distillation or by crystallization, (6a) is useful to generate compounds of Formula III, while (6b) is useful for similar elaboration to form compounds of Formula V. The acid (6a) is esterified and then treated at low temperature with lithium diisopropylamide followed by addition with an aldehyde or ketone to form an unsaturated aldol. The olefin is then oxidized to the epoxide with a peracid such as peracetic or m-chloroperoxybenzoic acid (Paquette, L.A., Org. Syn., (1969), Vol. 49, 62). The epoxide may be isolated or it may be allowed to react further so that the closed ring system IIIa is formed. These conditions provide primarily the stereoisomer wherein the alcohol is anti to the bridging oxygen. If the syn alcohol is desired, one route to this end is to oxidize IIIa (anti) to the ketone by a variety of methods such as that of Swern (Swern, D., Synthesis, (1981), 165) or Jones (see Bruce, W. F., Org. Synthesis, Coll. Vol. II, 139) followed by selective reduction with a reducing agent such as sodium borohydride to provide the required alcohol. Coupling under the above mentioned conditions provides III (X=CO₂R¹¹).

SCHEME 5

This ester may then be reduced and capped with a variety of capping reagents to provide III

(CR³R⁴OR¹⁸=X¹).

In a similar manner, (6b) may be elaborated through identical steps to compounds of Formula V as shown in Scheme 6.

SCHEME 6

The following non-limiting Examples illustrate preparation of the compounds of this invention.

EXAMPLE 1

4-ethyl-cyclohex-3-en-1-one

A three-neck, 1-L round bottom flask with

thermometer sidearm was fitted with a coldfinger

condenser, overhead stirrer on the middle neck,

thermometer, and a Claisen adapter. The whole apparatus was dried under a nitrogen stream while heating with a heat gun. The apparatus was allowed to cool under a nitrogen stream. Once at room temperature, a nitrogen line connected to a bubbler was connected to the bent neck of the Claisen head, the remaining straight neck being topped by a stopper. The apparatus was lowered into a -35°C bath (isopropanol precooled with dry ice) and maintained at that temperature either by periodic addition of dry ice to the bath or by use of a Cryocool cooling unit set at that temperature. The cold finger condenser was then charged with dry ice acetone and the NH3 (200 mL) was condensed into the flask to a preset mark. The stopper on the Claisen head was then replaced with an addition funnel charged with 30.0 g of

4-ethylanisole in 75 mL tetrahydrofuran (THF), which was added over 10 minutes to the ammonia with vigorous sitrring. The addition funnel was then charged with 65 mL of ethanol and this too was added over 10 minutes to the NH₃/THF mixture. The addition funnel was replaced by a stopper, the inlet line for the NH₃ was connected to a scrubber while the nitrogen line remained connected to the bent Claisen head. Pieces of Li metal (6.09 g) were added to the mixture by removing the stopper, dropping the piece in and replacing the stopper. This was done at such a rate that the blue color was discharged to a dull gray soon after the addition. In some cases there was a coppery bronze phase present instead of a blue color which must be watched for discharge. When 10 minutes is needed for complete discharge of all coloring to gray, the Li addition is stopped and the mixture is stirred for another 10 minutes at -35°C. A scoop of NH₄CI (about 2 g) is cautiously added to discharge any unreacted Li and the mixture is allowed to warm to room temperature over 2 hours while boiling off the NH3 through the scrubber. Once the mixture was at room temperature, 50 mL water followed by 200 mL ether were added slowly and the mixture stirred for half an hour. Celite (60 g) was added. The mixture was filtered and the filtrate was poured into a separatory funnel, the lower aqueous layer was drawn off and washed once with ether. The combined organic phases were concentrated to about 500 mL. At this point a solution of 3.3 g oxalic acid dihydrate in 75 mL of water was added and the mixture was stirred overnight (alternatively one may use 20 mL of 1N HCl with a stirring time of 6 hours). The mixture was poured into a separatory funnel and then separated; the aqueous layer was washed once with ether. The combined organic layers were washed first with 50 mL of saturated aqueous NaHCO₃ followed by 50 mL pH 7 buffer until the resulting aqueous layer had a neutral pH by pH paper. The organic layers were then dried over anhydrous Na₂SO₄, filtered and concentrated. The residue was distilled at 18 torr (b.p. 78-87°C) to obtain 22.6 g of oil.

1H-NMR (90 MHz, CDCI₃) : δ 5.5 (br s, 1H, olefinic), 2.9 (d, 2H, CH₂CO) , 2.5 (m, 4H, CH₂'s), 2.1 (app. q, 2H), 1.0 (t, 3H, CH₃). EXAMPLE 2

Methyl 4-ethyl-α,α-dimethyl-1- hydroxy-cyclohex-3-en-1-acetate

A 1-L one-neck flask with thermometer sidearm and magnetic stir bar was heated with a heat gun and allowed to cool, all under a nitrogen stream. A thermometer was fitted into the sidearm, and the neck was topped with a septum. A needle connected to a nitrogen bubbler was punched through the septum as a vent. The flask was charged with 330 mL of dry THF, followed by 14.7 mL of diisopropylamine. The flask was cooled to -10°C

(ice/acetone bath). N-Butyllithium (68 mL of a 1.6 M hexane solution) was added by syringe, keeping the internal temperature below 0°C. The mixture was stirred 15 minutes, then cooled to -78°C (dry ice/acetone bath) and added 15.0 mL of methyl isobutyrate dropwise over about 10 minutes. This mix was stirred 20 minutes at -78 to -70°C, then 12.42 g of 4-ethyl-cyclohex-3-en-1-one were added as a solution in 10 mL THF, followed by a washing of the flask that held the enone with another 10 mL of THF and addition of this to the anion mixture. The mixture was stirred another 30 minutes, then quenched at the low temperature with 1 to 1 saturated aqueous NH₄CI solution/water. The mix was then allowed to warm to room temperature and poured into a separatory funnel. The aqueous layer was drawn off and washed with ether. The combined organic layers were washed with saturated aqueous NaCl, dried over anhydrous Na₂SO₄, filtered, concentrated, and chromatographed on silica gel (gradient 10-20% ether/hexane, column was packed using 10% ether silica gel containing 1% triethylamine). The desired product was obtained (16.26 g) as an oil. ¹H-NMR (90 MHz, CDCl₃) : δ 5.3 (m, 1H, olefinic), 3.7 (s, 3H, OCH₃), 3.2 (s, 1H, OH), 2.6-1.5 (m, 8H), 1.3 (2 d, 6H, CH₃'s), 1.0 (t, CH₂CH₃). EXAMPLE 3

Methyl exo-4-ethyl-α,α-dimethyl- 3-hydrpxy-7-oxabicyclo[2.2.1]heptane-1-acetate Methyl 4-ethyl-α,α-dimethyl-1-hydroxy-cyclohex-3- en-1-acetate (16.26 g) was dissolved in dry

dichloromethane. Molecular sieves (3A, 2g) were added to the mix. The suspension was cooled to -10°C (ice/acetone bath). Vanadyl acetylacetonate (0.38 g) was added. The mixture was stirred for 20 minutes. Tert-butyl

hydroperoxide (9.6 mL of a 90% material dissolved in 20 mL of dichloromethane) was added by addition funnel over 1 hour. The solution was stirred at about -10°C for an hour, then the ice bath was removed and the mixture was allowed to warm to room temperature over the next 30 minutes. Camphorsulfonic acid (0.67 g) was added and the mixture was stirred overnight. The reaction did not seem finished by TLC, so another 0.67 g of camphorsulfonic acid was added; the reaction was stirred another 4 hours . The mixture was filtered through Celite, rinsing with ether. The filtrate was washed successively with

saturated aqueous NaHSθ3, 10% aqueous

Ethylenediaminetetraacetic acid (EDTA) , and saturated aqueous NaCl. The combined organic layers were dried over anhydrous Na2Sθ4, filtered, concentrated, and

chromatographed on silica gel (60% ether/hexane) to obtain 9.05 g title compound as an oil.

1H-NMR (200 MHz, CDCI₃): δ 3.75 (br d, 1H, CHOH), 3.58 (s, 3H, OMe), 2.3-1.35 (m, 8H), 1.21 (s, 3H, CH₃), 1.20 (s, CH₃), 0.85 (t, 3H, CH₂CH₃). EXAMPLE 4

Methyl exo-4-ethyl-α,α-dimethyl-3- (phenylmethoxy)-7-oxabicyclo[2.2.1]heptane-1-acetate

Methyl exo-4-ethyl-α,α-dimethyl-3-hydroxy-7- oxabicyclo[2.2.1]heptane-1-acetate (1.0 g) and benzyl bromide (0.75 mL) were dissolved in 4 mL THF and 4 mL dimethylacetamide. A magnetic stirring bar was added, and the mixture was cooled to about 10°C under nitrogen. Potassium tert-butoxide (0.92 g) was added portionwise over about 10 minutes. After the addition, the mixture was allowed to warm to room temperature and stirred another 4 hours. The rection was quenched with saturated aqueous NH₄CI and extracted with hexanes twice. The combined organic layers were dried over anhydrous Na₂SO₄, filtered, concentrated, chromatographed on silica gel (20% ether/hexane) to obtain 1.35 g of title compound contaminated with less than 10% benzyl ester.

1H-NMR (200 MHz, CDCI₃) : δ 7.32 (br s, 5H, aromatics), 4.42 (2H, AB quartet, CH₂Ar), 3.55-3.7 (s with multiplet shoulder, 4H, OCH₃, CHOCH₂Ar), 2.2-1.2 (m, 14H), 0.9 (t, CH₂CH₃).

IR (neat): 2960, 1730, 1460, 1360, 1275, 1150, 1125, 980, 730, 690 cm^-1. EXAMPLE 5

Methyl exo-4-ethyl-α,α-dimethyl-3-(2-fluorophenylmethoxy)-7-oxabicyclo[2 .2.1]heptane-1-acetate Methyl exo-4-ethyl-α,α-dimethyl-3-hydroxy-7-oxabicyclo[2.2.1]heptane-l-acetate (1.0 g) and 2-fluorobenzyl bromide were dissolved in 4 mL THF and 4 mL dimethylacetamide. A magnetic stirring bar was added and the mixture was cooled under nitrogen to -10°C.

Potassium tert-butoxide (0.93 g) was added in three portions over 10 minutes. The mixture was warmed to room temperature and stirred for another 4 hours. The reaction was quenched with saturated aqueous NH4CI and extracted twice with hexanes. The combined organic layers were washed with saturated aqueous NaCl, dried over anhydrous Na₂SO₄, filtered, concentrated,

chromatographed on silica gel (20% ether/hexane) to get 1.35 g of title compound containing a trace (less than 5%) of benzyl ester.

1H-NMR (200 MHz, CDCI₃): δ 7.5-6.9 (m, 4H, aromatics), 4.48 (2H, AB quartet, OCH₂Ar), 3.67 (app s, 4H, CH₃, CHOCH₂Ar), 2.2-1.2 (m, 14H), 0.88 (t, CH₂CH₃).

IR (neat): 2960, 1730, 1620, 1590, 1490, 1360, 1275, 1230, 1190, 830, 750 cm^-1. EXAMPLE 6

Exo-1-Ethyl-4-(2-hydroxy-1,1-dimethylethyl)- 2-(phenylroethoxy)-7-pχabicyclo[2.2.1]heptane Methyl exo-4-ethyl-α,oc-dimethyl-3-(phenyl)- methoxy)-7-oxabicyclo[2.2.1]heptane-l-acetate (0.52 g) was dissolved in 3 mL dry THF and cooled to -10°C under nitrogen (methanol/ice bath). Lithium aluminum hydride as a 1 M solution in THF (1.44 mL) was added over 5 minutes. The solution was allowed to warm to room temperature and stirred for 2 hours. Then it was cooled to 0°C and 0.055 mL water was added carefully. The suspension was stirred 10 minutes, at which time 0.055 mL of 15% aqueous NaOH was added followed by 0.16 mL water. The mixture was stirred for 1 hour. It was then filtered through a filter pad of about 1 to 1 Celite/Na2S04, rinsing with ether. After concentration, the residue was chromatographed on silica gel (50% ether/hexane) to obtain 0.46 g of title alcohol.

1H-NMR (200 MHz, CDCI₃): δ 7.82 (br s, 5H, aromatics), 4.4 (AB quartet, 2H, CH₂Ar), 3.7-3.3 (m, 5H, CH₂OH, CflOCH₂Ar), 2.2-1.1 (m, 6H), 1.03 (s, 3H, CH₃), 1.00 (s, 3H, CH₃), 0.91 (t, 3H, CH₂CH₃).

IR (neat): 3600-3300 (br), 2980, 2885, 1460, 1355, 1200, 1110, 1050, 900, 730, 690 cm^-1.

EXAMPLE 7

Exo-1-Ethyl-4-(2-methoxy-1,1-dimethylethyl)-2- phenylmethoxy)-7-oxabicyclo[2.2.1]heptane Exo-1-ethyl-4-(2-hydroxy-1,1-dimethylethyl)-2- (phenylmethoxy)-7-oxabicyclo[2.2.1]heptane (0.2 g) and iodomethane (0.06 mL) were added dissolved in 0.65 mL THF and 0.65 mL dimethylacetamide. Potassium tert-butoxide (0.14 g) were added and the reaction stirred for 1 hour. An additional 0.30 mL of iodomethane was added. Since the reaction was going slowly, 0.03 g of sodium hydride (60%) were added. After another hour, 0.4 mL of

iodomethane and 0.03 g sodium hydride were added and the reaction was stirred for an additional hour. Water was then added, followed by extraction with hexanes twice. The combined organics were dried over anhydrous Na2S04, filtered, concentrated, chromatographed on silica gel (10% ether/hexane) to obtain 0.18 g of title compound as an oil.

1H-NMR (200 MHz, CDCI₃): δ 7.3 (s, 5H, aromatics), 4.4 (AB quartet, 2H, OCH₂Ar), 3.6 (dd, CHOCH₂Ar), 3.3 (s, 3H, OCH₃), 3.3 (s, 2H, CCH₂O), 2.2-0.8 (m, 12H).

IR (neat): 2960, 2860, 1450, 1105, 1055, 900, 725 cm^-1.

EXAMPLE 8

Exo-4-(2-ethoxy-1,1-dimethylethyl)-1- ethyl-2-phenylmethoxy)-7-oxabicyclo[2.2.1]heptane

Exo-1-ethyl-4-(2-hydroxy-1,1-dimethylethyl)-2-(phenylmethoxy)-7-oxabicyclo[2.2.1]heptane (0.2 g) and bromoethane (0.08 mL) were dissolved in 0.65 mL THF and 0.65 mL dimethylacetamide. The reaction was cooled to 0°C under nitrogen, and added 0.05 g of 60% sodium hydride. The mixture was stirred for four hours at which time an additional 0.03 g sodium hydride and 0.08 mL bromoethane were added. After another hour of stirring, saturated aqueous NH₄CI was added and the mixture was extracted with hexane, the aqueous layer was then

extracted with ether once. The combined organic layers were dried over anhydrous Na2S04, filtered, concentrated, chromatographed on silica gel to obtain 0.18 g of title compound as an oil.

1H-NMR (200 MHz, CDCI₃) : δ 7.3 (m, 5H, aromatics), 4.45 (AB quartet, 2H, CH₂Ar), 3.6 (m, 1H, CHOCH₂Ar), 3.45 (AB quartet, 2H, CH₂CH₃) , 3.3 (s, 2H, CH₂OEt) , 2.2-0.8 (m, 15H).

IR (neat) : 2970, 2860, 1455, 1380, 1350, 1110, 1060,

900, 725, 690 cm^-1.

EXAMPLE 9

Exo-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)- 7-oxabicyclo[2.2.1]heptane-1-ethanol methanesulfonate Exo-1-ethyl-4-(2-hydroxy-1,1-dimethylethyl)-2- (phenylmethoxy)-7-oxabicyclo[2.2.1]heptane (0.1 g) was dissolved in 1.5 mL of dichloromethane under nitrogen. The solution was cooled to 0°C. Triethylamine (0.07 mL) was added followed by methanesulfonyl chloride (0.03 mL). The mixture was stirred for 1 hour at 0°C. Then ice was added and the mixture was extracted with ether. The layers were separated, the aqueous was washed again with ether. The combined organic layers were dried over

Na₂SO₄, filtered, concentrated, and chromatographed on silica gel (505 ether/hexane) to obtain 0.12 g of title compound as an oil. ¹H-NMR (200 MHz, CDCI₃) : δ 7.3 (s, 5H, aromatics), 4.45 (AB quartet, 2H, CH₂Ar), 4.2 (s, 2H, CCH₂O), 3.6 (m, 1H, CHOCH₂Ar), 3.0 (s, 3H, SO₂CH₃), 2.2-0.8 (m, 12H).

IR (neat): 2970, 1455, 1350, 1170, 1115, 1055, 950, 900, 840, 725, 690 cm^-1.

EXAMPLE 10

Methyl 4-ethyl-α-methyl-1- hydroxy-cyclohex-3-en-1-acetate

A 500 mL round bottom flask was heat dried under an N2 stream. Diisopropylamine (4.35 mL) was dissolved in 80 mL of dry tetrahydrofuran. This was cooled to -10°C, N-BuLi (1.6M in hexanes, 20.4 mL) was added to this such that the temperature remained below +5°C. Stirred 10 minutes. The solution was cooled to -78°C. Methyl propionate (3.8 mL) was added. The ester enolate

solution was stirred 20 minutes after which time 4-ethyl-cyclohex-3-en-1-one (4.5 g, see Example 1) was added as a solution in 5 mL THF. This was stirred 40 min at -78°C. The mix was quenched at -78° with 60 mL of 1.1 saturated aqueous NH₄Cl:H₂O. The mix was warmed to room

temperature. The layers were separated. The organic layer was washed with saturated aqueous NaCl, dried over MgSO₄, filtered, concentrated, and chromatographed by passage through a filter column of SiO₂ (0-50% Et₂O/hex).¹H-NMR of the isolated product (5.15g) showed it to be about 85% desired salt and 15% starting enone (76% yield product).

1H-NMR (90 MHz, CDCI₃) : δ 5.3 (br s, olefinic H's, 1H); 3.8 (s, 3H, OCH₃); 3.2 (d, 1H, CHCO₂CH₃); 3.0-1.9 (m). EXAMPLE 11

Methyl exo-4-ethyl-α-methyl-3- hydroxy-7-oxabicyclo[2.2.1]heptane-1-acetate Methyl 4-ethyl-α-methyl-1-hydroxy-cyclohex-3-ene-1- acetate (5.15g) was dissolved in 100 mL dry CH₂CI₂ under N₂. Vanadylacetylacetonate (320 mg) was added and stirred 10 minutes. The solution was cooled to -10°C. To this stirred solution was added dropwise a solution made by dissolving 3.23 mL of 90% t-butyl hydroperoxide into 15 mL of CH₂CI₂ and drying the solution over 3Å molecular sieves. The solution was stirred 1 hr at - 10°C, then allowed to warm to room temperature and stirred 1 hr at room temperature. Camphorsulfonic acid (840 mg) was added to the mix which was then stirred 3 hrs. Then Et₂O was added followed by saturated aqueous NaHSO₃. The mixture was stirred 10 minutes and poured into a separatory funnel. More water was added. The layers were separated. The aqueous layer was washed with Et₂O. The combined organic layers were washed (in succession) with saturated aqueous NaHCO₃, 10% aqueous EDTA, and saturated aqueous NaCl. The organics were dried over MgSO₄, filtered, concentrated, and

chromatographed on SiO₂ (80-90% Et₂O/hex) to get 1.45 g desired product as an oil (26% yield).

1H-NMR (CDCI₃, 200 MHz): δ 3.9 (m, 1H, CHOH); 3.69 (s, 3H, OCH₃) 3.0 (q, 1H, CHCH₃); 2.2-1.4 (m); 1.27, 1.26 (2 d's, CHCH₃); 0.96 (t, 3H, CH₂CH₃).

EXAMPLE 12

Methyl exo-4-ethyl-α-methyl-3- (phenylmethoxy)-7-oxabicyclo[2,2,1]heptane-1-acetate

Methyl exo-4-ethyl-α-methyl-3-hydroxy-7-oxabicyclo[2.2.1]heptane-1-acetate (1.1 g) was dissolved in 5 mL CH₂CI₂ and 15 mL hexane. Added a small scoop of 3A molecular sieves. Added 2.7 g of benzyl 2,2,2- trichloroacetimidate. A stock solution of BF₃·Et₂O in CH₂CI₂ was made by dissolving 0.09 mL of BF₃·Et₂O in 0.91 mL of CH₂CI₂. Ten drops of this solution were added every hour for 5 hrs. At the end, added 5 drops of triethylamine and hexanes to precipitate by-products. This mixture was stirred 10 minutes and filtered through Celite, rinsing with 10% Et₂O/hexane. Concentrated the filtrate, chromatographed on Siθ2 (0-20% Et2θ/hexanes to obtain 1.30 g of desired product as an oil (84%). Have two diastereomers. Product is contaminated with some dibenzylether.

1H-NMR (CDCI₃, 200 MHz): δ 7.32 (br, s, 5H, aromatics); 4.6, 4.3 (2AB q., 2H, CH₂ Ph); 3.69-3.60 (2s, with multiplet, OCH₃, CHOCH₂Ph) ; 3.0 (m, 1H, CHCH₃); 2.2-1.4 (m, 8H); 1.30-1.26 (2d's, CHCH₃); 0.90 (t, 3H, CH₂CH₃). IR (neat, cm^-1): 3000, 1750, 1465, 1360, 1210, 1180, 1075, 1060, 995, 950, 740, 700. EXAMPLE 13

Exo-4-ethyl-α-α-dimethyl-3-

(phenylmethoxy)-7-oxabicyclo[2.2.1]heptane-1-al.

A 200 mL flask was heat dried under N₂. Once cooled, this flask was charged with CH₂CI₂ (18 mL) under N2, followed by 0.45 mL of oxalyl chloride. The mixture was cooled to -78 °C. Dimethyl sulfoxide (1.71 mL) was added over 2 minutes. The mixture was stirred at -78 °C for 15 minutes. At this point, 1.31 g of exo-1-ethyl-4- (2-hydroxy-1,1-dimethylethyl)-2-(phenylmethoxy)-7-oxabicyclo[2.2.1]heptane as a solution in 3 mL CH₂CI₂ was added. The suspension was stirred for 15 minutes, after which 2.34 mL triethylamine was added and the mixture was allowed to warm to -40°C. Hexanes were then added followed by water. The cooling bath was removed and the mixture allowed to warm to room temperature. Poured into a separatory funnel; separated layers; washed the organic layer with saturated aqueous NaCl. The organic layer was dried over Na₂SO₄, filtered, concentrated,

chromatographed on SiO₂ (15% Et2θ/hex) to get 1.19 g of desired product as an oil (97%).

1H-NMR (200 MHz, CDCl₃): δ 9.8 (s, 1H, CHO); 7.35 (s, 5H, aromatics); 4.3-4.6 (AB q, 2H, CH₂Ar); 3.6 (m, 1H, CHOCH₂Ar); 0.8-2.2 (m).

EXAMPLE 14

Exo-1-ethyl-4-(2-hydroxy-1,1-dimethylbutyl)-2- (phenylmethpxy)-7-oxabicyclo[2.2.1]heptane. Exo-4-ethyl-α-α-dimethyl-3-(phenylmethoxy)-7- oxabicyclo[2.2.1]heptane-1-al was dissolved in 4.5 diethylether under N₂. This was cooled to -10°C.

Ethylmagnesium bromide (3.0 M in ether - 0.8 mL) was added dropwise. The mix was warmed to room temperature and stirred for 1 hr. at room temperature. The reaction was quenched with 0.15 mL of 2-propanol. The mixture was stirred 10 min. Then added more ether followed by 1:1 saturated aqueous NH₄Cl/water. The layers were

separated. The aqueous layer was washed again with ether. The combined organics were washed with 10%

aqueous EDTA, followed by saturated aqueous NaCl. The combined organics were dried over MgSO₄, filtered,

concentrated, and chromatographed on SiO₂ (20%

Et₂O/hexane) to get 600 mg desired product as an oil (91% yield).

1H-NMR (CDCl₃, 200 MHz): δ 7.35 (s, 5H, aromatics);

4.6-4.3 (AB q, 2H, CH₂Ar); 4.2 (d, 1H, CHOH); 3.7,3.6 (m, 2H, CHOH, CHOCH₂Ar); 2.1-0.8 (m). EXAMPLE 15

Exo-1-ethyl-4-(2-methoxy-1,1-dimethylbutyl)-2- (phenylmethoxy)-7-oxabicyclo[2.2.1]heptane.

Exo-1-ethyl-4-(2-hydroxy-lyl-dimethylbutyl)-2- (phenylmethoxy)-7-oxabicyclo[2.2.1]heptane 150 mg was dissolved in a mixture of 0.5 mL each of THF and

dimethylacetamide. Sodium hydride (60% dispersion in oil, 40 mg) was added followed by 0.06 mL iodomethane. The mixture was stirred overnite. Added saturated aqueous NH₄CI and extracted with hexane. The organic layers were dried over Na₂SO₄, filtered, concentrated, chromatographed on SiO₂ (0-20% Et₂O/hex) to obtain 150 mg of desired product as an oil (95%).

1H-NMR (200 MHz, CDCI₃) : δ 7.35 (d, 5H, aromatics);

4.6-4.3 (AB q, 2H, CR₂Ar) ; 3.6 (m, 1H, CHOCH₂Ar); 3.4 (s, 3H, OCH₃); 2.9 (m, 1H, C (H) (Et) OCH₃); 2.2-0.8 (m). IR (neat, cm^-1): 2995, 2895, 1465, 1390, 1370, 1110 (br), 1070, 910, 735, 700. EXAMPLE 16

Propyl exo-4-ethyl-α-α-dimethyl-3-hydroxy- 7-oxabicyclo[2.2.1]heptane-1-acetate.

Methyl exo-4-ethyl-α-α-dimethyl-3-hydroxy-7-oxabicyclo[2.2.1]heptane-1-acetate (500 mg) was dissolved in 10 mL n-propanol. 160 mg of sodium hydride (60% dispersion in oil) was added and the contents were heated at reflux for 4 hrs. Reaction was allowed to cool and then stirred overnight. Added saturated aqueous NH₄CI, extracted with ether, dried organics over Na₂SO₄,

filtered, concentrated, chromatographed to obtain 250 mg (45% yield) of desired product as an oil.

1H-NMR (200 MHz, CDCI₃): δ 4.1 (t, 2H, CH₂OC (O)); 3.8 (m, 1H, CHOH); 2.2-1.2 (m); 0.9 (t, 2H, CH₂CH₃). EXAMPLE 17

Propyl exo-4-ethyl-α-α-dimethyl-3-(2-fluorophenylmethoxy)-7-oxabicyclo[2.2.1]heptane-1-acetate.

Propyl exo-4-ethyl-α-cc-dimethyl-3-(hydroxy)-7- oxabicyclo[2.2.1]heptane-1-acetate (120 mg) was dissolved in 0.4 mL each of THF and dimethylacetamide. To this was added 0.08 mL 2-fluorobenzyl bromide followed by cooling to 0° (ice bath). Potassium t-butoxide (100 mg) was added and the reaction was allowed to warm to room temperature. It was then stirred for 4 hrs. Saturated aqueous NH₄CI was added and the mixture was extracted with hexane twice. The organics were dried over Na₂SO₄, filtered, concentrated, chromatographed on SiO₂ (10-15% Et₂O/hex) to get 140 mg of desired product as an oil.

1H-NMR (CDCl₃,200 MHz): δ 7.4-7.0 (m, 4H, aromatics); 4.5 (AB q, 2H, CH₂Ar); 4.03 (t, 2H, CH₂OC(O)); 3.65 (dd, 1H, CHOCH₂Ar); 2.1-0.9 (m).

IR (neat, cm^-1): 2900, 1720, 1450, 1280, 1150-1110-1060, 750.

EXAMPLE 18

Allyl exo-4-ethyl-α-α-dimethyl-3-hydroxy-7- oxabicyclo[2.2.1]heptane-1-acetate.

Methyl-exo-4-ethyl-α-α-dimethyl-3-hydroxy-7- oxabicyclo[2.2.1]heptane-1-acetate (500 mg) was dissolved in 5 mL of allyl alcohol. To this was added sodium hydride (160 mg of a 60% dispersion in oil). The

reaction was heated at reflux under N₂ for 1 hr, then allowed to cool down to room temperature. Quenched with saturated aqueous NH₄CI (about 2 mL). Removed some of the allyl alcohol. Diluted with water and extracted mixture twice with ether. Combined organics were washed with saturated NaCl, dried over Na₂SO₄, filtered, concentrated, chromatographed on SiO₂ to get 240 mg of desired alcohol as an oil.

¹H-NMR (200 MHz, CDCl₃): δ 5.95 (m, 1H, CH=CH₂); 5.3 (m, 2H, CH=CH₂); 4.6 (d- 2H, OCH₂ ester); 3.85 (dd, 1H, CHOH); 2.1-0.8 (m).

EXAMPLE 19

Allyl exo-4-ethyl-α-α-dimethyl-3-(phenylmethoxy)-7- oxabicyclo[2.2.1]heptane-1-acetate.

Allyl exo-4-ethyl-α-α-dimethyl-3-hydroxy-7- oxabicyclo[2.2.1]heptane-1-acetate (100 mg) was dissolved in 0.4 mL each of THF and dimethylacetamide. The mixture was cooled to 0°C (ice bath). Benzyl bromide (0.07 mL) was added followed by 80 mg of potassium t-butoxide. The mixture was allowed to warm to room temperature and stirred for a total of 4 hrs. Hexane was then added; the reaction was quenched with saturated aqueous NH4CI and extracted with more hexane. The organic layer was washed with saturated NaCl, dried over Na2≤O4, filtered,

concentrated, chromatographed on Siθ2 (10% Et2θ/hexane) to get 120 mg of desired product as an oil.

1H-NMR (200 MHz, CDCI₃) : δ 7.3 (s, 5H, aromatics); 6.0-5.8 (m, 1H, CH.=CH₂); 5.4-5.1 (m, 2H, CH=CH_₂); 4.55 (s, 2H, CH₂CH=CH.₂); 4.6-4.3 (AB q, 2H, CH₂Ar); 3.6 (dd, 1H, CHOCH₂Ar); 2.2-0.8 (m).

EXAMPLE 20

Ethyl exo-4-methyl-α-α-dimethyl-3- (2.6-riifluorophenylmethoxy)-7-oxabicyclo

[2.2.1]heptane-1-acetate.

Methyl-exo-4-ethyl-α-α-dimethyl-3-hydroxy-7-oxabicyclo[2.2.1]heptane-1-acetate (1.5 g) was dissolved in 15 mL ethanol. Contents were cooled to about 10°C.

Sodium hydride (740 mg of a 60% dispersion in oil) was added portionwise. The reaction flask was filtered with a condenser and placed under N₂. Then it was heated for 30 minutes. The reaction was allowed to cool and was quenched with saturated aqueous NH₄CI. The ethanol was removed in vacuo and water was added to the residue, which was then extracted with ether. Organic layer was dried over Na₂SO₄, filtered, concentrated,

chromatographed on SiO₂ (50-60% Et₂O/hex) to get 940 mg (59% yield) of the ethyl ester/alcohol as a product.

100 mg of this material was dissolved in 0.4 mL each of THF and dimethylacetamide. 120 mg of 2,6-difluoro- benzylbromide was added and the mixture was cooled to 0°C with an ice bath. Potassium t-Butoxide (90 mg) was added. The reaction was allowed to warm slowly to room temperature and stirred for a total of 4 hrs. Hexane was added, followed by saturated aqueous NH₄CI and extracted with more hexane. The organic layer was washed with saturated NaCl, dried over Na₂SO₄, filtered, concentrated chromatographed on Siθ2 (10% Et₂O/hex) to get 100 mg of desired product as an oil (67%).

1H-NMR (200 MHz, CDCI₃): δ 7.4-6.8 (m, 3H, aromatics); 4.7-4.3 (AB q, 2H, CH₂Ax); 4.2-4.0 (AB q, 2H, benzyl ester impurity); 3.6 (m, CHOCH₂,Ar, 1H); 2.1-0.8 (m). EXAMPLE 21

Exo-1-ethγl-4-(2-hydroxy-1,1-dimethylethyl)-2-(2- fluorophenylmethoxy)-7-oxabicyclo[2.2.1]heptane

Methyl-exo-4-ethyl-α-α-dimethyl-3-(2-fluorophenylmethoxy)-7-oxabicyclo[2,2,1]heρtane-1-acetate (1.35 g) was dissolved in 8 mL THF under N₂ and this solution was cooled to -10°C. Then added 3.85 mL of a THF

solution of lithium aluminum hydride over 5 minutes. The mixture was allowed to warm to room temperature and stirred for 1 hr. The mixture was cooled to 0°C and to this was added 0.15 mL water. The mixture was stirred for 10 minutes, followed by addition of 0.15 mL of 15% NaOH (aqueous), followed by 0.45 mL of water. The suspension was stirred for 2 hrs, then filtered through Celite which contained some Na₂SO₄, rinsing with ether. The filtrate was concentrated and chromatographed on SiO₂ (40% Et₂O/hex) to get 1.18 g of desired product as an alcohol (95%).

1H-NMR (200 MHz, CDCI₃): δ 7.5-7.0 (m, 4H, aromatics); 4.65-4.35 (AB q, 2H, CH₂Ar); 3.65 (m, 1H, CHOCH₂,Ar);

3.6-3.4 (m, 3H, CH₂OH); 2.1-0.9 (m).

EXAMPLE 22

Exo-1-ethyl-4-(2-fluorophenylmethoxy)-7- oxabicyclo[2. 2.1]heptane

Exo-1-ethyl-4-(2-hydroxy-1,1-dimethyl)-2-(2-fluorophenylmethoxy)-7-oxabicyclo[2.2.1]heptane (150 mg) was dissolved in 0.5 mL each of THF and dimethylacetamide.

Sodium hydride (40 mg of a 60% dispersion in oil) was added and the mixture stirred for 30 minutes. Propargyl bromide (0.07 mL of an 80% solution in toluene) was added and the mixture was stirred overnight. Added hexane and quenched with saturated aqueous NH₄CI. Extracted with more hexane. The organic layers were washed with

saturated NaCl, dried over Na₂SO₄, filtered,

concentrated, and chromatographed on SiO₂ (10-20%

Et₂O/hex) to get 140 mg (84%) as an oil.

1H-NMR (200 MHz, CDCI₃) : δ 7.5-6.95 (m, 4H, aromatics);

4.65-4.35 (AB q, CH₂Ar 2H,); 4.15 (d, 2H, CH₂OCH₂CCH); 3.65 (m, 1H, CHOCH₂Ar); 3.4 (s, 2H, CH₂OCH₂CCH); 2.4 (s,

1H, C≡CH) ; 2.2-0.8 (m).

IR (neat, cm^-1): 3320, 3000-2900, 1500, 1440, 1370,

1235, 1100, 1075, 760. EXAMPLE 23

Methyl 4-ethyl-α-chloro-α-methyl-1- hydroxy-cyclohex-3-en-1-acetate

A 200 mL round bottom flask was heat dried under a N2 stream and allowed to cool to room temperature. THF (35 mL) and diisopropylamine (1.78 mL) were added in succession. The solution was cooled to -10°C and n-BuLi (8.3 mL of a 1.6M solution in hexane) was added, keeping the temperature below 5°C. The reaction was stirred 10 min, then cooled to -78°C. Methyl 2-chloropropionate (1.79 mL) was added and stirring was continued for 10 minutes at which time 1.5 g of 4-ethyl-cyclohex-3-en-1- one in 5 mL THF was added, followed by stirring for 10 minutes. At -78°C, 1:1 saturated aqueous NH₄CI/H₂O was added and the reaction warmed to room temperature and extracted with ether twice; the combined organics were washed with saturated NaCl, dried over MgSO₄, filtered, concentrated and chromatographed (SiO₂, 20-40% Et₂O/hex) to get 1.36 g (45%) desired product as an oil.

1H-NMR (CDCI₃, 200 MHz): δ 5.3 (br s, 1H, olefinic); 3.85 (s, 3H, OCH₃); 3.0-0.8 (m).

EXAMPLE 24

Methyl exo-4-ethyl-α-chloro-α-methyl-3-hydroxy-7- oxabicyclo[2.2.1]heptane-1-acetate

Methyl-4-ethyl-α-chloro-α-methyl-1-hydroxycyclohex-3-en-1-acetate (1.36 g) was dissolved in 25 mL dry CH₂CI₂ under N₂. Vanadylacetylacetonate (50 mg) was added to the solution and this was stirred for 10

minutes. The solution was cooled to -10°C and a solution of 0.80 mL t-butyl-hydroperoxide in CH₂CI₂ (5 mL), which had been dried over 4A molecular sieves, was added to the stirred solution of alcohol and vanadium complex. After the addition, the solution was stirred further at -10°C, then warmed to room temperature and stirred 2 hrs more. 70 mg camphorsulfonic acid was added and the reaction was stirred overnight. Another 60 mg of acid was added and stirring was continued for another 3 hrs. Saturated aqueous NaHSO₃ was added and the mix was extracted with ether. The ether was washed with 10% aqueous EDTA, then saturated aqueous NaCl, dried over MgSO₄, filtered, concentrated, and chromatographed (60% Et₂O/hex) to get (43%) 630 mg of desired product as an oil.

1H-NMR (CDCl₃, 200 MHz): δ 3.9 (m, 1H, CHOH); 3.8 (s, 3H, OCH₃); 2.3-0.9 (m).

EXAMPLE 25

Methyl exo-4-ethyl-α-chloro-α-methyl-3- (2-fluorophenylmethoxy)-7-oxabicyclo[2.2.1]heptane-1-acetate

Methyl exo-4-ethyl-α-chloro-α-methyl-3-hydroxy-7-oxabicyclo[2.2.1]heptane-1-acetate (700 mg) was dissolved in 2.66 mL each of THF and dimethylacetamide. 2-Fluoro- benzylbromide (0.64 mL) was added and the reaction was cooled to. Potassium t-butoxide (600 mg) was added and the reaction was slowly allowed to warm to room

temperature and stirred a total of 6 hrs. Saturated aqueous NH₄CI was added to the mixture and this was extracted with hexane twice. The combined organics were washed with saturated aqueous NaCl, dried over Na₂SO₄, filtered, concentrated, chromatographed on SiO₂ (5-10% Et₂O/hex) to get 580 mg of desired diastereomers as an oil (59%).

1H-NMR (200 MHz, CDCI₃) : δ 7.5-6.95 (m, 4H, aromatics); 4.65-4.35 (2AB q, 2H, CH₂Ar); 3.8 (s, 3H, OCH₃); 3.75 (m, 1H, CHOCH₂Ar); 2.2-0.8 (m).

IR (neat, cm^-1): 2975, 2880, 1745, 1495, 1455, 1270, 1230, 1115, 1090, 1060, 760. The compounds of Tables 1-5 may be prepared by the general procedures described in Schemes 1-6 and Examples 1-25 or by obvious modifications thereof.

Formulations

Useful formulations of the compounds of Formula I can be prepared in conventional ways. They include dusts, granules, pellets, solutions, suspensions, emulsions, wettable powders, emulsifiable concentrates and the like. Many of these may be applied directly. Sprayable formulations can be extended in suitable media and used at spray volumes of from a few liters to several hundred liters per hectare. High strength compositions are primarily used as intermediates for further

formulation. The formulations, broadly, contain about 0.1% to 99% by weight of active ingredient(s) and at least one of (a) about 0.1% to 20% surfactant(s) and (b) about 1% to 99.9% solid or liquid diluent(s). More specifically, they will contain these ingredients in the following approximate proportions:

Lower or higher levels of active ingredient can, of course, be present depending on the intended use and the physical properties of the compound. Higher ratios of surfactant to active ingredient are sometimes desirable, and are achieved by incorporation into the formulation or by tank mixing.

Typical solid diluents are described in Watkins, et al., "Handbook of Insecticide Dust Diluents and

Carriers", 2nd Ed., Dorland Books, Caldwell, New Jersey, but other solids, either mined or manufactured, may be used. The more absorptive diluents arepreferred for wettable powders and the denser onesfor dusts. Typical liquid diluents and solvents are described in Marsden, "Solvents Guide," 2nd Ed., Interscience, New York, 1950. Solubility under 0.1% is preferred for suspension

concentrates; solution concentrates are preferably stable against phase separation at 0°C. "McCutcheon' s

Detergents and Emulsifiers Annual", MC Publishing Corp., Ridgewood, New Jersey, as well as Sisely and Wood,

"Encyclopedia of Surface Active Agents", Chemical

Publishing Co., Inc., New York, 1964, list surfactants and recommended uses . All formulations can contain minor amounts of additives to reduce foaming, caking,

corrosion, microbiological growth, etc.

The methods of making such compositions are well known. Solutions are prepared by simply mixing the ingredients. Fine solid compositions are made by

blending and, usually, grinding as in a hammer or fluid energy mill. Suspensions are prepared by wet milling (see, for example, Littler, U.S. Patent 3,060,084).

Granules and pellets may be made by spraying the active material upon preformed granular carriers or by

agglomeration techniques. See J. E. Browning,

"Agglomeration", Chemical Engineering, December 4, 1967, pp. 147ff. and "Perry's Chemical Engineer's Handbook", 5th Ed., McGraw-Hill, New York, 1973, pp. 8-57ff.

For further information regarding the art of formulation, see for example:

H. M. Loux, U.S. Patent 3,235,361, February 15,

1966, Col. 6, line 16 through Col. 7, line 19 and

Examples 10 through 41;

R. W. Luckenbaugh, U.S. Patent 3,309,192, March 14,

1967, Col. 5, line 43 through Col. 7, line 62 and

Examples 8, 12, 15, 39, 41, 52, 53, 58, 132, 138-140,

162-164, 166, 167 and 169-182;

H. Gysin and E. Knusli, U.S. Patent 2,891,855,

June 23, 1959, Col. 3, line 66 through Col. 5, line 17 and Examples 1-4;

G. C. Klingman, "Weed Control as a Science", John

Wiley and Sons, Inc., New York, 1961, pp. 81-96; and

J. D. Fryer and S. A. Evans, "Weed Control

Handbook", 5th Ed., Blackwell Scientific Publications,

Oxford, 1968, pp. 101-103.

In the following examples, all parts are by weight unless otherwise indicated.

Example A

Wettable Powder

exo-(+/-)-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)-7-oxabicyclo-[2.2.1]heptane-1-ethanol methanesulfonate 60%

sodium alkylnaphthalenesulfonate 2% sodium ligninsulfonate 2% synthetic amorphous silica 36%

The active ingredient is first sprayed onto the amorphous silica, then the ingredients are blended, hammer-milled until all the solids are essentially under 50 microns, reblended, and packaged. Example B

Wettable Powder

exo-(+/-)-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)-7-oxabicyclo-[2.2.1]heptane- -1-ethanol methanesulfonate 50%

sodium alkylnaphthalenesulfonate 2% low viscosity methyl cellulose 2% diatomaceous earth 46% The active ingredient is first sprayed onto the diatomaceous earth then the ingredients are blended, coarsely hammer-milled and then air-milled to produce particles essentially all below 10 microns in diameter. The product is reblended before packaging.

Example C

Granule

Wettable Powder of Example B 5% attapulgite granules 95%

(U.S.S. 20-40 mesh; 0.84-0.42 mm)

A slurry of wettable powder containing 25% solids is sprayed on the surface of attapulgite granules in a double-cone blender. The granules aredried and packaged. Example D

Emulsifiable Concentrate

exo-(+/-)-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)-7-oxabicyclo-[2.2.1]heptane- -1-ethanol methanesulfonate 40%

Atlox 3403F 3%

Atlox 3404F 3% xylene 54%

The active ingredient and Atlox emulsifiers are dissolved in the solvent, filtered and packaged. Atlox 3403F and 3404F are blends of anionic and ionic

emulsifiers from ICI Americas, Inc.

Example E

Low Strength Granule

exo-(+/-)-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)-7-oxabicyclo-[2.2.1]heptane-1-ethanol methanesulfonate 5%

attapulgite granules 95%

(U.S.S. 20-40 mesh)

The active ingredient is dissolved in a solvent and the solution is sprayed upon dedusted granules in a double-cone blender. After spraying of the solution has been completed, the material is warmed to evaporate the solvent. The material is allowed to cool and then packaged.

Example F

Granule

exo-(+/-)-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)-7-oxabicyclo-[2.2.1]heptane¬

-1-ethanol methanesulfonate 50%

wetting agent 1% crude ligninsulfonate salt (containing 10%

5-20% of the natural sugars)

attapulgite clay 39%

The ingredients are blended and milled to pass through a 100 mesh screen. This material is then added to a fluid bed granulator, the air flow is adjusted to gently fluidize the material, and a fine spray of water is sprayed onto the fluidized material. The fluidization and spraying are continued until granules of the desired size range are made. The spraying is stopped, but fluidization is continued, optionally with heat, until the water content is reduced to the desired level, generally less than 1%. The material is then discharged, screened to the desired size range, generally 14-100 mesh (1410-149 microns), and packagedfor use. Example G

Concentrated Emulsion

exo-(+/-)-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)-7-oxabicyclo-[2.2.1]heptane-1-ethanol methanesulfonate 25%

xylene 25%

Atlox 3404F 5%

G1284 5% ethylene glycol 8% water 32%

The active ingredient, solvent and emulsifiers are blended together. This solution is added to a mixture of the ethylene glycol and water with stirring.

Example H

Solution

exo-(+/-)-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)-7-oxabicyclo-[2.2.1]heptane-1-ethanol methanesulfonate 5%

water 95%

The compound is added directly to the water with stirring to produce the solution, which may then be packaged for use.

Example I

Dust

exo-(+/-)-4-ethyl-β,β-dimethyl-3-(phenylmethoxy)-7-oxabicyclo-[2.2.1]heptane-1-ethanol methanesulfonate 10%

attapulgite 10%

Pyrophyllite 80% The active ingredient is sprayed onto the

attapulgite and then passed through a hammer-mill to produce particles substantially all below 200 microns. The ground concentrate is then blended with powdered pyrophyllite until homogeneous. UTILITY

Test results indicate compounds of this invention are active postemergence and, in particular, preemergence herbicides. Many compounds in this invention are useful for the control of selected grass and broadleaf weeds with tolerance to important agronomic crops such as barley (Hordeum vulgare), corn (Zea mays), cotton

(Gossypium hirsutum), rape (Brassica napus), rice (Qryza sativa), sorghum (Sorghum bicolor), soybean (Glycine max), sugar beet (Beta vulgaris), and wheat (Triticum aestivum), and to vegetable crops. Grass and broadleaf weed species controlled include, but are not limited to, barnyardgrass (Echinochloa crus-galli), blackgrass

(Alopecurus myosuroides). crabgrass (Digitaria spp.), duck salad (Heteranthera limosa), foxtail (Setaria spp.), velvetleaf (Afutilon theophrasti), lambsquarters

(Chenopodium spp. ) , and umbrella sedge (Cyperus

difformis). Several compounds in this invention are particularly useful for the control of barnyardgrass and selected broadleaf weeds such as duck salad and umbrella sedge in upland and paddy rice.

The following are examples of compounds that

demonstrated excellent weed control and crop tolerance: In Table A compounds 1 and 2 gave excellent preemergence grass weed control in corn, cotton, soybeans and rice. Also in Table A compound 85 gave excellent preemergence grass weed control in soybeans, cotton and rice. In Table B compound 19 was excellent for grass weed control in corn, soybeans and cotton; compounds 23 and 103 gave outstanding barnyardgrass control in rice and compound 25 was excellent for blackgrass control in wheat.

The aforesaid compounds also have utility for weed control of selected vegetation in specified areas such as around storage tanks, parking lots, highways, and

railways; in fallow crop areas; and in citrus and

plantation crops such as banana, coffee, oil palm, and rubber. Alternatively, said compounds are useful to modify plant growth.

A herbicidally effective amount of the compounds of this invention is determined by a number of factors.

These factors include: formulation selected, method of application, amount and type of vegetation present, growing conditions, etc. In general terms, a

herbicidally effective amount of the subject compounds is applied at rates from 0.01 to 20 kg/ha with a preferred rate range of 0.03 to 1 kg/ha. Although a small number of compounds show no herbicidal activity at the rates tested, it is anticipated these compounds are

herbicidally active at higher application rates. One skilled in the art can easily determine application rates necessary for the herbicidally effective amount that will achieve the desired level of weed control.

Compounds of this invention may be used alone or in combination with other commercial herbicides,

insecticides, or fungicides. The following list

exemplifies some of the herbicides suitable for use in mixtures. A combination of a compound from this

invention with one or more of the following herbicides may be particularly useful for weed control. Common Name Chemical Name

acetochlor 2-chloro-N-(ethoxymethyl)-N- (2-ethyl-6-methylphenyl)acetamide acifluorfen 5-[2-chloro-4-(trifluoromethyl)- phenoxy]-2-nitrobenzoic acid aclonifen 2-chloro-6-nitro-3-phenoxybenzenamine

acrolein 2-propenal

alachlor 2-chloro-N-(2,6-diethylphenyl)-N- (methoxymethyl)acetamide

alloxydim methyl 2,2-dimethyl-4,6-dioxo-5-[1- [(2-propenyloxy)amino]butylidene] cyclohexanecarboxylate

ametryn N-ethyl-N'-(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine amitrole 1H-1,2,4-triazol-3-amine

AMS ammonium sulfamate

anilofos S-[2-[(4-chlorophenyl)(1-methylethyl)amino]-2-oxoethyl]

O,O-dimethylphosphorodithioate asulam methyl [(4-aminophenyl)sulfony1]- carbamate

atrazine 6-chloro-N-ethyl-N'-(1-methylethyl)- 1,3,5-triazine-2,4-diamine

aziprotryne 4-azido-N-(1-methylethyl)-6-methylthio-1,3,5-triazin-2-amine

azoluron N-(1-ethyl-1H-pyrazol-5-yl)-N'- phenylurea

barban 4-chloro-2-butynyl 3-chlorocarbamate Common Name Chemical Name

benazolin 4-chloro-2-oxo-3(2H)-benzothiazole- acetic acid

benfluralin N-butyl-N-ethyl-2,6-dinitro-4- (trifluoromethyl)benzenamine bensulfuron 2-[[[[[(4,6-dimethoxy-2-pyrimidinyl)amino]methylcarbonyl]amino]- sulfonyl]methyl]benzoic acid, methyl ester

bensulide O,O-bis(1-methylethyl) S-[2- [(phenylsulfonyl)amino]ethyl]- phosphorodithioate

bentazon 3-(1-methylethyl)-(1H)-2,1,3- benzothiadiazin-4(3H)-one,

2,2-dioxide

benzofluor N-[4-(ethylthio)-2-(trifluoromethyl)phenyl]methanesulfonamide benzoylprop N-benzoyl-N-(3,4-dichlorophenyl)-DL- alanine

benzthiazuron N-2-benzothiazolyl-N'-methylurea bialaphos 4-(hydroxymethylphosphinyl)-L-2- aminobutanoyl-L-alanyl-L-alanine bifenox methyl 5-(2,4-dichlorophenoxy)-2- nitrobenzoate

bromacil 5-bromo-6-methyl-3-(1-methylpropyl)- 2,4(1H,3H)pyrimidinedione

*bromobutide (+)2-bromo-3,3-dimethyl-N-(1-methyl- 1-phenylethyl)butanamide

bromofenoxim 3,5-dibromo-4-hydroxybenzaldhyde O- (2,4-dinitrophenyl)oxime Common Name Chemical Name

bromoxynil 3,5-dibromo-4-hydroxybenzonitrile bromuron N'-(4-bromopheny1)-N,N-dimethylurea buminafos dibutyl [1-(butylamino)cyclohexyl]- phosphonate

butachlor N-(butoxymethyl)-2-chloro-N-(2,6- diethylphenyl)acetamide

butamifos O-ethyl O-(5-methyl-2-nitrophenyl)- (lmethyIpropyl)phosphoramidothioate

buthidazole 3-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-4-hydroxy-1-methyl-2- imidazolidinone

butralin 4-(1,1-dimethylethyl)-N-(1-methylpropyl)-2,6-dinitrobenzenamine butylate S-ethyl bis(2-methyIpropyl)- carbamothioate

cacodylic dimethyl arsinic oxide

acid

carbetamide (R)-N-ethyl-2-[[(phenylamino)- carbonyl]oxy]propanamide

CDAA 2-chloro-N,N-di-2-propenylacetamide CDEC 2-chloroallyl diethyldithiocarbamate chlomethoxyfen 4-(2,4-dichlorophenoxy)-2-methoxy-1- nitrobenzene

chloramben 3-amino-2,5-dichlorobenzoic acid chlorbromuron 3-(4-bromo-3-chlorophenyl)- 1-methoxy-1-methylurea

chlorbufam 1-methyl-2-propynl(3-chlorophenyl)- carbamate

chlorfenac 2,3,6-trichlorobenzeneacetic acid Common Name Chemical Name

chlorflurecol- methyl 2-chloro-9-hydroxy- methyl 9H-fluorene-9-carboxylate chloridazon 5-amino-4-chloro-2-phenyl-3(2H)- pyridazinone

chlorimuron 2-[[[[(4-chloro-6-methoxy-2-pyrimidinyl)ethylamino]carbonyl]- amino]sulfonyl]benzoic

acid, ethyl ester

chlornitrofen 1,3,5-trichloro-2-(4-nitrophenoxy)- benzene

chloropicrin trichloronitromethane

chloroxuron N'-[4-(4-chlorophenoxy)phenyl]-N,N- dimethylurea

chlorpropham 1-methylethyl 3-chlorophenyl- carbamate

chlorsulfuron 2-chloro-N-[[(4-methoxy-6-methyl- 1,3,5-triazin-2-yl)amino]- carbonyl]benzenesulfonamide chlorthal- 2,3,5,6-tetrachloro-1,4- dimethyl benzenedicarboxylate

chlorthiamid 2,6-dichlorobenzene carbothioamide chlortoluron N'-(3-chloro-4-methylphenyl)-N,N- dimethylurea

cinmethylin exo-1-methyl-4-(1-methylethyl)-2- [(2-methylphenyl)methoxy]-7- oxabicyclo[2.2.1]heptane

clethodim (E,E)-(+)-2-[1-[[(3-chloro-2- propenyl)oxy]imino]propyl]- 5-[2-(ethylthio)propyl]-3-hydroxy- 2-cyclohexen-1-one Common Name Chemical Name

clomazone 2-[(2-chlorophenyl)methyl]-4,4- dimethyl-3-isoxazolidinone

cloproxydim (E,E)-2-[1-[[(3-chloro-2- propeny1)oxy)imino]butyl]-5-[2- (ethylthio)propyl]-3-hydroxy-2- cyclohexen-1-one

clopyralid 3,6-dichloro-2-pyridinecarboxylie acid

CMA calcium salt of MAA

cyanazine 2-[[4-chloro-6-(ethylamino)-1,3,5- triazin-2-yl]amino]-2-methylpropanenitrile

cycloate S-ethyl cyclohexylethylcarbamothioate cycloxydim 2-[1-ethoxyimino)butyl]-3-hydroxy- 5-(tetrahydro-2H-thiopyran-3-yl)- 2-cyclohexene-1-one

cycluron 3-cyclooctyl-1,1-dimethylurea

cyperquat 1-methyl-4-phenylpyridinium

cyprazine 2-chloro-4-(cyclopropylamino)-6-(iso- propylamino)-s-triazine

cyprazole N-[5-(2-chloro-l,1-dimethylethyl)- 1,3,4-thiadiazol-2-yl]cyclopropanecarboxamide

cypromid 3',4'-dichlorocyclopropanecarboxanilide

dalapon 2,2-dichloropropanoic acid

dazomet tetrahydro-3,5-dimethyl-2H-1,3,5- thiadiazine-2-thione Common Name Chemical Name

DCPA dimethyl 2,3,5,6-tetrachloro-l,4- benzenedicarboxylate

desmedipham ethyl [3-[[(phenylamino)carbonyl]- oxy]phenyl]carbamate

desmetryn 2-(isopropylamino)-4-(methylamino)-6- (methylthio)-s-triazine

diallate S-(2,3-dichloro-2-propenyl)bis(1- methylethyl)carbamothioate

dicamba 3,6-dichloro-2-methoxybenzoic acid dichlobenil 2,6-dichlorobenzonitrile

dichlorprop (+)-2-(2,4-dichlorophenoxy)propanoic acid

*diclofop(+)-2-[4-(2,4-dichlorophenoxy)- methyl phenoxy]propanoic acid, methyl

ester

diethatyl N-(chloroacetyl)-N-(2,6-diethylphenyl)glycine

difenoxuron N'-[4-(4-methoxyρhenoxy)phenyl]-N,N- dimethylurea

difenzoquat 1,2-dimethyl-3,5-diphenyl-1H- pyrazoliumion

diflufenican N-(2,4-difluorophenyl)-2-(3-trifluoromethylphenoxy)pyridine-3- carboxamide

dimefuron N'-[3-chloro-4-[5-(1,1-dimethylethyl)-2-oxo-1,3,4-oxadiazol-3(2H)- yl]phenyl]-N,N-dimethylurea

dimethachlor 2-chloro-N-(2,6-dimethylphenyl)-N-(2- methoxyethyl)acetamide Common Name Chemical Name

dimethametryn N-(1,2-dimethyIpropyl)-N'-ethyl-6- (methylthio)-1,3,5-triazine- 2,4-diamine

dimethipin 2,3-dihydro-5,6-dimethyl-1,4- dithiin 1,1,4,4-tetraoxide

dimethylarsinic dimethylarsinic acid

dinitramine N³,N³-diethyl-2,4-dinitro-6- (trifluoromethyl)-1,3-benzenediamine

dinoseb 2-(1-methyIpropyl)-4,6-dinitrophenol dinoterb 2-(1,1-dimethylethyl)-4,6- dinitrophenol

diphenamid N,N-dimethyl-α-phenylbenzeneacetamide

dipropetryn 6-(ethylthio)-N,N'-bis(1-methylethyl)-1,3,5-triazine-2,4-diamine diquat 6,7-dihydrodipyrido[1,2-a:2',1'-c]- pyrazinediium ion

diuron N'-(3,4-dichlorophenyl)-N,N- dimethylurea

DNOC 2-methyl-4,6-dinitrophenol

DPX-V9360 2-[[(4,6-dimethoxypyrimidin-2- yl)aminocarbonyl]aminosulfonyl]- N,N-dimethyl-3-pyridinecarboxamide

DSMA disodium salt of MAA

dymron N-(4-methylphenyl)-N^,-(1-methyl-1- phenylethyl)urea Common Name Chemical Name

eglinazine-ethyl N-[4-chloro-6-(ethylamino)- 1,3,5-triazin-2-yl]glycine ethyl ester

endothall 7-oxabicyclo[2.2.1]heptane- 2,3-dicarboxylic acid

EPTC S-ethyl dipropylcarbamothioate ethaifluralin N-ethyl-N-(2-methyl-2-propenyl)-2,6- dinitro-4-(trifluoromethyl)- benzenamine

ethidimuron N-[5-(ethylsulfonyl)-1,3,4- thiadiazol-2-yl]-N,N'-dimethylurea *ethofumesate (+)-2-ethoxy-2,3-dihydro-3,3- dimethyl-5-benzofuranyl

methanesulfonate

fenac 2,3,6-trichlorobenzeneacetic acid *fenoprop (+)-2-(2,4,5-trichlorophenoxy)- propanoic acid

*fenoxaprop (+)-2-[4-[(6-chloro-2-benzoxazolyl)- oxy]phenoxy]propanoic acid fenuron N,N-dimethyl-N'-phenylurea

fenuron TCA Salt of fenuron and TCA

flamprop-M- 1-methylethyl N-benzoyl-N-(3-chloro- isopropyl 4-fluorophenyl)-D-alanine

flamprop-methyl methyl N-benzoyl-N-(3-chloro-4- fluorophenyl)-DL-alaninate

*fluazifop (+)-2-[4-[[5-(trifluoromethyl)- 2-pyridinyl]oxy]phenoxy]propanoic acid Common Name Chemical Name

fluazifop-P (R)-2-[4-[[5-(trifluoromethyl)- 2-pyridinyl]oxy]phenoxy]propanoic acid

fluchloralin N-(2-chloroethyl)-2,6-dinitro- N-propyl-4-(trifluoromethyl)- benzenamine

fluometuron N,N-dimethyl-N'-[3-(trifluoromethyl)phenyl]urea

fluralin N-butyl-N-ethyl-2,6-dinitro- 4-(trifluoromethyl)benzenamine fluorodifen p-nitrophenyl α,α,α-trifluoro- 2-nitro-p-tolyl ether

fluoroglycarboxymethyl 5-[2-chloro-4-(tricofen fluoromethyl)phenoxy]-2- nitrobenzoate

flurecol-butyl butyl 9-hydroxy-9H-fluorene- 9-carboxylate

fluridone 1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone flurochloridone 3-chloro-4-(chloromethyl)- 1-[3-(trifluoromethyl)phenyl]- 2-pyrrolidinone

fluroxypyr [(4-amino-3,5-dichloro-6-fluoro-2- pyridinyl)oxy]acetic acid fomesafen 5-[2-chloro-4-(trifluoromethyl)- phenoxy]-N-(methylsulfonyl)- 2-nitrobenzamide

fosamineethyl hydrogen (aminocarbonyl)- ammonium phosphonate ammonium ethyl

Common Name Chemical Name

glufosinate- ammonium 2-amino-4-(hydroxy- ammonium methylphosphinyl)butanoate glyphosate N-(phosphonomethyl)glycine

haloxyfop 2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]- phenoxyjpropanoic acid

hexaflurate potassium hexafluoroarsenate hexazinone 3-cyclohexyl-6-(dimethylamino)- 1-methyl-1,3,5-triazine-2,4- (1H,3H)-dione

imazametha6-(4-isopropyl-4-methyl-5-oxo-2- benz imidazolin-2-yl)-m-toluic acid, methyl ester and 6-(4-isopropyl- 4-methyl-5-oxo-2-imidazolin- 2-yl)-p-toluic acid, methyl ester

imazapyr (+)-2-[4,5-dihydro-4-methyl-4- (1-methylethyl)-5-oxo-1H-imidazol- 2-yl]-3-pyridinecarboxylic acid imazaquin 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol- 2-yl]-3-quinolinecarboxylic acid imazethapyr (+)-2-[4,5-dihydro-4-methyl-4- (1-methylethyl)-5-oxo-1H-imidazol- 2-yl]-5-ethyl-3-pyridinecarboxylic acid

ioxynil 4-hydroxy-3,5-diiodobenzonitrile isocarbamid N-(2-methyIpropyl)-2-oxo-1- imidazolidinecarboxamide

Common Name Chemical Name

isopropalin 4-(1-methylethyl)-2,6-dinitro-N,N- dipropylbenzenamine

isoproturon N-(4-isopropylphenyI)-N',N'- dimethylurea

isouron N'-[5-(1,1-dimethylethyl)-3- isoxazolyl]-N,N-dimethylurea isoxaben N-[3-(1-ethy1-1-methyIpropyl)-5- isoxazolyl]-2,6-dimethoxybenzamide

karbutilate 3-[[(dimethylamino)carbonyl]amino]- phenyl-(1,1-dimethylethyl)- carbamate

lactofen (+)-2-ethoxy-1-methyl-2-oxoethyl

5-[2-chloro-4-(trifluoromethyl)- phenoxy]-2-nitrobenzoate

lenacil 3-cyclohexyl-6,7-dihydro-1H- cyclopentapyrimidine-2,4(3H,5H)- dione

linuron N'-(3,4-dichlorophenyl)-N-methoxy-N- methylurea

MAA methylarsonic acid

MAMA monoammonium salt of MAA

MCPA (4-chloro-2-methylphenoxy)acetic

acid

MCPA-thioethyl S-ethyl (4-chloro-2-methylphenoxy)- ethanethioate

MCPB 4-(4-chloro-2-methylphenoxy)butanoic acid

Common Name Chemical Name

mecoprop (+)-2-(4-chloro-2-methylphenoxy)- propanoic acid

mefenacet 2-(2-benzothiazolyloxy)-N-methyl-N- phenyl acetamide

mefluidide N-[2,4-dimethyl-5-[[(trifluoromethyl)sulfonyl]amino]phenyl]- acetamide

metamitron 4-amino-3-methyl-6-phenyl-l,2,4- triazin-5(4H)-one

metazachlor 2-chloro-N-(2,6-dimethylphenyl)-N- (1(H)-pyrazol-1-ylmethyl)- acetamide

methabenz- 1,3-dimethyl-3-(2-benzothia- thiazuron zolyl)urea

methal- N-(2-methyl-2-propenyl)-2,6-dinitro- propalin N-propyl-4-(trifluoromethyl)- benzenamide

metham methylcarbamodithioic acid

methazole 2-(3,4-dichlorophenyl)-4-methyl- 1,2,4-oxadiazolidine-3,5-dione methoxuron N'-(3-chloro-4-methoxyphenyl)-N,N- dimethylurea

methoxyphenone (4-methoxy-3-methylphenyl)(3-methyl- phenyl)methanone

methyldymron N-methyl-N'-(1-methyl-1-phenyl- ethyl)-N-phenylurea

metobromuron N'-(4-bromophenyl)-N-methoxy-N- methylurea

metolachlor 2-chloro-N-(2-ethyl-6-methylphenyl)- N-(2-methoxy-1-methylethyl)- acetamide Common Name Chemical Name

metoxuron N'-(3-chloro-4-methoxyphenyl)-N,N- dimethylurea

metribuzin 4-amino-6-(1,1-dimethylethyl)-3- (methylthio)-1,2,4-triazin- 5(4H)-one

metsulfuron 2-[[[[(4-methoxy-6-methyl-l,3,5-tri- methyl azin-2-yl)amino]carbonyl]- amino]sulfonyl]benzoic acid, methyl ester

MH 1,2-dihydro-3,6-pyridazinedione molinate S-ethyl hexahydro-1H-azepine- 1-carbothioate

monalide N-(4-chlorophenyl)-2,2-dimethyl- pentanamide

monolinuron 3-(p-chlorophenyl)-1-methoxy-1- methylurea

monuron N'-(4-chlorophenyl)-N,N-dimethylurea

MSMA monosodium salt of MAA

naproanilide 2-(2-naphthalenyloxy)-N-phenyl- propanamide

napropamide N,N-diethyl-2-(1-naphthalenyloxy)- propanamide

naptalam 2-[(1-naphthalenylamino)carbonyl]- benzoic acid

neburon 1-butyl-3-(3,4-dichlorophenyl)- 1-methylurea

nitralin 4-methylsulfonyl-2,6-dinitro-N,N- dipropylaniline Common Name Chemical Name

nitrofen 2,4-dichloro-1-(4-nitrophenoxy)- benzene

nitrofluorfen 2-chloro-1-(4-nitrophenoxy)-4-(trifluoromethyl)benzene

norea N,N-dimethy1-N'-(octahydro-4,7- methano-1H-inden-5-yl)urea

3aα, 4α, 5α, 7α, 7aα-isomer

norflurazon 4-chloro-5-(methylamino)-2-[3-(trifluoromethyl)phenyl]-3(2H)- pyridazinone

orbencarb S-[2-(chlorophenyl)methyl]diethyl- carbamothioate

oryzalin 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide

oxadiazon 3-[2,4-dichloro-5-(1-methylethoxy)- phenyl]-5-(1,1-dimethylethyl)- 1,3,4-oxadiazol-2(3H)-one oxyfluorfen 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)- benzene

paraquat 1,1'-dimethy1-4,4'-dipyridinium ion pebulate S-propyl butylethylcarbamothioate pendimethalin N-(1-ethyIpropyl)-3,4-dimethyl-2,6- dinitrobenzenamine

perfluidone 1,1,1-trifluoro-N-[2-methyl-4- (phenylsulfonyl)phenyl]methanesulfonamide

phenisopham 3-[[(1-methylethoxy)carbonyl]amino]- phenyl ethylphenylcarbamate phenmedipham 3-[(me(hoxycarbonyl)amino]phenyl (3- methylphenyl)carbamate Common Name Chemical Name

picloram 4-amino-3, 5, 6-trichloro-2-pyridine- carboxylic acid

piperophos S-[2-(2-methyl-1-piperidinyl)-2-oxo- ethyl]O,O-dipropyl phosphorodithioate

pretilachlor 2-chloro-N-(2,6-diethylphenyl)-N-(2- propoxyethyl)acetamide

procyazine 2-[[4-chloro-6-(cyclopropylamino)- 1,3,5-triazine-2-yl]amino]-2- methylpropanenitrile

prodiamine 2,4-dinitro-N³,N³-dipropyl- 6-(trifluoromethyl)-1,3-benzenediamine

profluralin N-(cyclopropylmethyl)-2,6-dinitro-N- propyl-4-(trifluoromethyl)- benzenamine

proglinazine- N-[4-chloro-6-[(1-methylethyl)- ethyl amino]-1,3,5-triazin-2-yl]glycine ethyl ester

prometon 6-methoxy-N,N'-bis(1-methylethyl)- 1,3,5-triazine-2,4-diamine

prometryn N,N'-bis(1-methylethyl)-6- (methylthio)-1,3,5-triazine- 2,4-diamine

pronamide 3,5-dichloro-N-(1,1-dimethyl- 2-propynyl)benzamide

propachlor 2-chloro-N-(1-methylethyl)-N-phenylacetamide

propanil N-(3,4-dichlorophenyl)propanamide propaquizafop 2-[[(1-methylethylidene)amino]- oxy]ethyl-2-[4-[(6-chloro- 2-quinoxalinyl)oxy]phenoxy]- propanoate Common Name Chemical Name

propazine 6-chloro-N,N'-bis(1-methylethyl)- 1,3,5-triazine-2,4-diamine propham 1-methylethyl phenylcarbamate propyzamide 3,5-dichloro-N-(1,1-dimethyl- 2-propynl)benzamide

prosulfalin N-[[4-(dipropylamino)-3,5-dinitrophenyl]sulfonyl]-S,S-dimethyl- sulfilimine

prosulfocarb S-benzyldipropylthiocarbamate prynachlor 2-chloro-N-(1-methyl-2-propynyl)- acetanilide

pyrazon 5-amino-4-chloro-2-phenyl-3(2H)- pyridazinone

pyrazosulfuron- ethyl 5-[[[[(4,6-dimethoxy-2- ethyl pyrimidinyl)amino]carbonyl]amino]- sulfonyl]-1-methyl-1H-pyrazole- 4-carboxylate

pyrazoxyfen 2-[[4-(2,4-dichlorobenzoyl)-1,3- dimethyl 1H-pyrazol-5-yl] oxy] -1- phenylethanone

pyridate O-(6-chloro-3-phenyl-4-pyridazinyl)

S-octyl carbonothioate

quizalofop (+)-2-[4-[(6-chloro-2-quinoxalinyl)- ethyl oxy]phenoxy]propanoic acid,

ethyl ester

secbumeton N-ethyl-6-methoxy-N'-(1-methyl- propyl)-1,3,5-triazine-2,4-diamine sethoxydim 2-[1-(ethoxyimino)butyl]-5-[2- (ethylthio)propyl]-3-hydroxy-2- cyclohexen-1-one Common Name Chemical Name

siduron N-(2-methylcyclohexyl)-N'-phenylurea simazine 6-chloro-N,N'-diethyl-1,3,5- triazine-2,4-diamine

simetryn N,N'-diethyl-6-(methylthio)-1,3,5- triazine-2,4-diamine

sodium chlorate sodium chlorate

sodium mono- chloroacetic acid, sodium salt

chloroacetate

sulfometuron 2-[[[[(4,6-dimethyl-2-pyrimidinyl)- methyl amino]carbonyl]amino]sulfonyl]- benzoic acid, methyl ester

2,4,5-T (2,4,5-trichlorophenoxy)acetic acid 2,3,6-TBA 2,3,6-trichlorobenzoic acid

TCA trichloroacetic acid

tebutam 2,2-dimethy1-N-(1-methylethyl)-N- (phenylmethyl)propanamide tebuthiuron N-[5-(1,1-dimethylethyl)-1,3,4- thiadiazol-2-yl]-N,N'-dimethyl- urea

terbacil 5-chloro-3-(1,1-dimethylethyl)- 6-methyl-2,4(1H,3H)-pyrimidine- dione

terbuchlor N-(butoxymethyl)-2-chloro-N-[2-(1,1- dimethylethyl)-6-methylphenyl]- acetamide

terbumeton N-(1,1-dimethylethyl)-N'-ethyl- 6-methoxy-1,3,5-triazine-2,4- diamine

terbuthyl2-(tert-butylamino)-4-chloro- azine 6-(ethylamino)-s-triazine Common Name Chemical Name

terbutol 2,6-di-tert-butyl-p-tolyl

methylcarbamate

terbutryn N-(1,1-dimethylethyl)-N'-ethyl- 6-(methylthio)-1,3,5-triazine- 2,4-diamine

thifensulfuron 3-[[[[(4-methoxy-6-methyl- 1,3,5,triazin-2-yl)amino]- carbonyl]amino]sulfonyl]- 2-thiophenecarboxylic acid, methyl ester

thiameturonmethyl 3-[[[[(4-methoxy-6- methyl methyl-1,3,5-triazin-2-yl)amino]- carbonyl] amino] sulfonyl]2-thio- phenecarboxylate

thiazafluron N,N'-dimethyl-N-[5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl]urea thiobencarb S-[(4-chlorophenyl)methyl] diethyl- carbamothioate

tiocarbazil S-(phenylmethyl) bis(1-methyl- propyl)carbamothioate

tralkoxydim 2-[1-(ethoxyimino)propyl]- 3-hydroxy-5-(2,4,6-trimethylphenyl)-2-cyclohexen-1-one

triallate S-(2,3,3-trichloro-2-propenyl)

bis(1-methylethyl)carbamothioate triasulfuron 2-(2-chloroethoxy)-N-[[(4-methoxy-6- methyl-1,3,5-triazin-2-yl)amino]- carbonyl]benzenesulfonamide tribenuron 2-[[[[N-(4-methoxy-6-methyl- methyl 1,3,5-triazine-2-yl)-N-methyl- amino]carbonyl]amino]sulfonyl]- benzoic acid, methyl ester Common Name Chemical Name

triclopyr [(3,5,6-trichloro-2-pyridinyl)oxy]- acetic acid

*tridiphane (+)2-(3,5-dichlorophenyl)-2-(2,2,2- trichloroethyl)oxirane

trietazine 6-chloro-N,N,N'-triethyl-1,3,5-tri- azine-2,4-diamine

trifluralin 2,6-dinitro-N,N-dipropyl-4-(tri- fluoromethyl)benzenamine

trimeturon 1-(p-chlorophenyl)-2,3,3-tri- methylpseudourea

2,4-D (2,4-dichlorophenoxy) acetic acid 2,4-DB 4-(2,4-dichlorophenoxy)butanoic acid vernolate S-propyl dipropylcarbamothioate xylachlor 2-chloro-N-(2,3-dimethylphenyl)-N- (1-methylethyl)acetamide

Selective herbicidal properties of the subject compounds were discovered in greenhouse tests as described below.

SPECTRAL DATA

The nuclear magnetic resonance (NMR) and infrared (IR) data are shown in Tables 7, 8 and 9. Entries for 1H-NMR (CDCI₃, 200 MHz) are in parts per million for the protons (H's) corresponding to the carbons numbered below:

Compounds 4 , 5, 6, 9, 13 , 31 and 44 contain 5-20% of the corresponding benzyl ester (X¹=CO₂R¹¹ , R¹¹=CH₂Ph, not claimed by the present invention and herbicidally inactive at the disclosed test rates).

TEST A

Seeds of barley (Hordeum vulgare), barnyardgrass (Echinochloa crus-galli), bedstraw (Galium aparine) , blackgrass (Alopecurus myosuroides), cheatgrass (Bromus secalinus), chickweed (Stellaria media), cocklebur

(Xanthium pensylvanicum), com (Zea mays) , cotton

(Gossypium hirsutum), crabgrass (Digitaria spp.), giant foxtail (Setaria faberii), lambsquarters (Chenopodium album), morningglory (Ipomoea hederacea), rape (Brassica nap us), rice (Oryza sativa), sorghum (Sorghum bicolor), soybean (Glycine max), sugar beet (Beta vulgaris), velvetleaf (Abutilon theophrasti), wheat (Triticum aestivum), wild buckwheat (Polygonum convolvulus), and wild oat (Avena fatua) and purple nutsedge (Cyperus rotundus) tubers were planted and treated preemergence with test chemicals dissolved in a non-phytotoxic

solvent. At the same time, these crop and weed species were also treated with postemergence applications of test chemicals. Plants ranged in height from two to eighteen cm (one to four leaf stage) for postemergence treatments. Treated plants and controls were maintained in a

greenhouse for twelve to sixteen days, after which all species were compared to controls and visually evaluated. Plant response ratings, summarized in Table A, are based on a scale of 0 to 10 where 0 is no effect and 10 is complete control. A dash (-) response means no test result.

TEST B

The compounds evaluated in this test were formulated in a non-phytoxic solvent and applied to the soil surface before plant seedlings emerged (preemergence

application), to water that covered the soil surface

(paddy application), and to plants that were in the one- to-four leaf stage (postemergence application). A sandy loam soil was used for the preemergence and postemergence tests, while a silt loam soil was used in the paddy test. Water depth was approximately 2.5 cm for the paddy test and was maintained at this level for the duration of the test.

Plant species in the preemergence and postemergence tests consisted of barley (Hordeum vulgare), bedstraw (Galium aparine), blackgrass (Alopecurus myosuroides), chickweed (Stellaria media), cocklebur (Xanthium

pensylvanicum), corn (Zea mays), cotton (Gossypium hirsutum), crabgrass (Diyitaria sanςminalis), downy brome (Bromus tectorum), duck salad (Heteranthera limosa), giant foxtail (Setaria faberii), green foxtail (Setaria viridis), jimsonweed (Datura stramonium), johnsongrass (Sorghum halepense), lambsquarters (Chenopodium album), morningglory (Ipomoea hederacea), pigweed

(Amaranthusretroflexus), rape (Brassica napus), rice (Oryza sativa), ryegrass (Lolium multiflorum), sicklepod (Cassia obtusifolia), sorghum (Sorghum bicolor), soybean (Glycine max), speedwell (Veronica persica), sugar beet (Beta vulgaris), teaweed (Sida spinosa), velvetleaf

(Abutilon theophrasti), wheat (Triticum aestivum), wild buckwheat (Polygonum convolvulus) and wild oat (Avenafatua) and purple nutsedge (Cyperus rotundus). All plant species were planted one day before application of the compound for the preemergence portion of this test.

Plantings of these species were adjusted to produce plants of appropriate size for the postemergence portion of the test. Plant species in the paddy test consisted of barnyardgrass (Echinochloa crus-galli), rice (Oryza sativa), and umbrella sedge (Cyperus difformis).

All plant species were grown using normal greenhouse practices. Visual evaluations of injury expressed on treated plants, when compared to untreated controls, were recorded approximately fourteen to twenty-one days after application of the test compound. Plant response

ratings, summarized in Table B, were recorded on a 0 to 10 scale where 0 is no injury and 10 is complete control. A dash (-) response means no test result.

TEST C

Plastic pots were partially filled with silt loam soil. The soil was then flooded with water, Japonica rice (Oryza sativa) sprouted seeds and 1.5 leaf transplants were planted in the soil. Seeds of barnyardgrass

(Echinochloa crus-galli) were planted in saturated soil and plants grown to the 1 leaf, 2 leaf and 3 leaf stages for testing. At testing, the water level for all

plantings was raised to 2 cm above the soil surface.

Chemical treatments were formulated in a non-phytotoxic solvent and applied directly to the paddy water. Treated plants and controls were maintained in a greenhouse for approximately 21 days, after which all species were compared to controls and visually evaluated. Plant response ratings, summarized in Table C are reported on a 0 to 10 scale where 0 is no effect and 10 is complete control. A dash (-) response means no test result.

O oo

TEST D

Plastic pots were partially filled with silt loam soil. The soil was then saturated with water. Indica and Japonica rice (Qryza sativa) seedlings at the 2.0 to 2.5 leaf stage, seeds selected from barnyardgrass

(Echinochloa crus-galli), bulrush (Scirpus mucronatus). duck salad (Heteranthera limosa), umbrella sedge (Cyperus difformis), and tubers selected from arrowhead

(Sagittaria spp.), waterchestnut (Eleocharis spp.), were planted into this soil. After planting, water levels were raised to 3 cm above the soil surface and maintained at this level throughout the test. Chemical treatments were formulated in a non-phytotoxic solvent and applied directly to the paddy water. Treated plants and controls were maintained in a greenhouse for approximately 21 days, after which all species were compared to controls and visually evaluated. Plant response ratings,

summarized in Table D, are reported on a 0 to 10 scale where 0 is no effect and 10 is complete control. A dash (-) response means no test result.

TEST E

Seeds of barnyardgrass (Echinochloa crus-galli), corn (Zea mays), cotton (Gossypimn hirsutam), crabgrass (Digitaria spp.), fall panicum (Panicum dicholomiflorum), giant foxtail (Setaria faberii), green foxtail (Setaria vividis), Johnson grass (Sorghum halepense), signalgrass (Brachiaria platyphylia), soybean (Glycine max) and wild proso (Pancium miliaceum) were planted into a silt loam soil. Test chemicals, dissolved in a non-phytotoxic solvent, were then applied to the soil surface within one day after the seeds were planted. Pots receiving these preemergence treatments were placed in the greenhouse and maintained according to routine greenhouse procedures. Treated plants and untreated controls were maintained in the greenhouse approximately 21 days after application of the test compound. Visual evaluations of plant injury responses were then recorded. Plant response ratings, summarized in Table E, are reported on a 0 to 10 scale where 0 is no effect and 10 is complete control.

Claims

What is claimed:

1. Compounds of the Formulas

wherein

X¹ is OR⁹, C0₂R^1:L, C(O)R^1:L, CHO, C(O)NR¹²R¹³, SH, S(O)_nR^1O, SO₂NR¹²R^l3, SO₂N(OCH₃) (CH₃), NHR¹⁶,

NR¹⁶R¹⁷, CH=NOR¹⁴, C (R¹¹)-NOR¹⁴ or CR⁴R⁵Y;

X² is CO₂R¹¹, C(O)R¹¹, CHO, C(O)NR¹²R¹³, S(O)_nR¹⁵, SO₂NR¹²R¹³, SO₂N(OCH₃) (CH₃), CH=NOR¹⁴, C(R¹¹)=NOR¹⁴ or CR⁴R⁵Y;

Y is OR¹⁸, CO₂R¹⁹, C(O)R¹⁹, CHO, C(O)NR²⁰R²¹, SH, S(O)_nR²², SO₂NR²⁰R²¹, SO₂N(OCH₃) (CH₃), NHR²³, NR²³R²⁴, P(O)(OR²⁹)₂, CH=NOR²⁵ or C(R¹¹)=NOR²⁵; n is O, 1 or 2;

R¹ is H or a straight chain C₁-C₃ alkyl; R² and R⁴ are independently H, C₁-C₃ alkyl, C₁-C₃ alkoxy or halogen;

R³ and R⁵ are independently H or C₁-C₃ alkyl;

R² and R³ may be taken together to form a 3- to 5- membered ring;

R⁴ and R⁵ may be taken together to form a 3- to 5- membered ring;

R⁶ is H or C₁-C₄ alkyl;

R⁷ and R⁸ are independently H, C₁-C₄ alkyl, C₂-C₄ alkenyl, C₂-C₄ alkynyl or C₁-C₃ alkyl substituted with OCH3 or OCH2CH3;

R⁹ and R¹⁸ are independently H, C₁-C₆ alkyl

optionally substituted with halogen, C₁-C₂ alkoxy, CN or CO₂CH₃; C₃-C₆ alkenyl optionally substituted with halogen or C₁-C₂ alkoxy; C₃-C₆ alkynyl; SO₂R¹⁰; C(O)NR¹²R¹³; P(O)(R¹⁶)₂;

P (O) (OR¹⁶)2; or benzyl;

R¹⁰ is C₁-C₄ alkyl optionally substituted with

halogen; or allyl;

R¹¹ and R¹⁹ are independently C₁-C₄ alkyl optionally substituted with C₁-C₂ alkoxy, C₁-C₂ alkylthio, halogen or NR¹²R¹³; C₃-C₄ alkenyl; C₃-C₄ alkynyl;

CH₂-cyclopropyl; or cyclobutyl;

R¹² and R¹³, are independently H, C₁-C₃ alkyl or may be taken together to form a 4- to 6-membered ring;

R²⁰ and R²¹ are independently H, C₁-C₃ alkyl or may be taken together to form a 4- to 6-membered ring;

R¹⁴ and R²⁵ are independently H, C₁-C₃ alkyl or

allyl;

R¹⁵ and R²² are independently C₁-C₄ alkyl;

R¹⁶, R¹⁷, R²⁴ and R²⁹ are independently C₁-C₃ alkyl; R²³ is C₁-C₃ alkyl, C(O)(C₁-C₂ alkyl), SO₂ (C₁-C₂ alkyl), C(O)NHCH₃ or C(O)N((CH₃)₂;

Q is CH₂W or

R²⁶ is H, halogen, C₁-C₃ alkyl, OR²⁷, SR²⁷ or CN;

R²⁷ is C₁-C₃ alkyl or C₁-C₃ haloalkyl;

Z is CH₂, NR²⁸, O, S or may be CH and taken to form a double bond with an adjacent carbon;

R²⁸ is H or C₁-C₃ alkyl;

q is 0, 1 or 2;

r is 0, 1 or 2; and

W is phenyl optionally substituted with 1-3

substituents selected from halogen, C₁-C₃ alkyl, C₁-C₃ alkoxy, OH, CN, C₁-C₃ haloalkyl, C₁-C₃ haloalkoxy, C₁-C₃ alkylthio, C₂-C₄ alkenyl and

C₂-C₄ alkynyl, or W is 5-, 6- or 7-membered heterocyclic ring containing one or more

heteroatoms selected from the group 0-2

nitrogens, 0-2 oxygens and 0-2 sulfurs, each ring optionally substituted with 1-2 substituents selected from halogen, CH₃ and OCH₃;

provided that

1) the sum of q and r is 0-2;

2) if the sum of q and r is O then Z is CH2;

3) in compounds of Formula I when R¹, R² and R³ are CH₃ and W is phenyl, then X¹ is other than

C(O)NH₂, O(C₁-C₃ alkyl), O(i-propyl), OH or SO₂CH₃; 4) in compounds of Formula I when R¹, R² and R³ are CH₃ and W is 2F-phenyl or 3CF₃-phenyl, then X¹ is other than CO2CH3; and

5) in compounds of Formula I when R¹, R² and R³ are CH₃ and W is 2F-phenyl, then X¹ is other than

C(O)N(CH₃)₂.

Compounds of Claim 1 wherein:

Q is CH2W or

W is phenyl, tetrahydropyran, tetrahydrofuran, thiophene, isoxazole, pyridine or pyrazine, each ring optionally substituted with 1-2 substituents selected from halogen, CH₃ and OCH₃;

3. Compounds of Claim 2 wherein

X¹ is OR⁹, CO₂R¹¹, C(O)R¹¹, CHO, C(O)NR¹²R¹³, SH,

H=NOR¹⁴,C(R¹¹)=NOR¹⁴ or CR⁴R⁵Y;

X² is CO₂R¹¹, C(O)R¹¹, CHO, C(O)NR¹²R¹³, CH=NOR¹⁴, C(R¹¹)=NOR¹⁴ or CR⁴R⁵Y;

R⁹ is H, C₁-C₃ alkyl, allyl, propargyl or SO2CH3;

R¹¹ is C₁-C₃ alkyl or allyl;

R¹² is H or CH₃;

R¹³ is CH₃;

R¹⁸ is H, C₁-C₃ alkyl, allyl, propargyl or SO₂(C₁- C₃ alkyl);

R²² is C₁-C₂ alkyl;

R²⁹ is CH₃; 4. Compounds of Claim 3 wherein

R¹ is C₁-C₂ alkyl;

R² and R⁴ are independently H, F, Cl, C₁-C₂ alkyl or OCH₃;

R³ and R⁵ are independently H or C₁-C₂ alkyl; R⁶ is H or C₁-C₂ alkyl;

R⁷ and R⁸ are independently H or C₁-C₂ alkyl.

5. Compounds of Claim 4 wherein

Q is CH₂W;

W is phenyl optionally substituted by 1-2

substituents selected from halogen and CH₃; tetrahydropyran; tetrahydrofuran; thiophene optionally substituted with Cl or Br; or pyridine.

Compounds of Claim 5 wherein

X¹ and X² are independently CO₂(C₁-C₃ alkyl),

CO₂-allyl,

C(O)(C₁-C₂ alkyl) or CR⁴R⁵Y; Y is O(C₁-C₂ alkyl), OSO₂CH₃ or O-propargyl; R² and R⁴ are indepedently H, Cl or CH₃;

7. Compounds of Claim 3 wherein

X¹ is OR⁹ or CR⁴R⁵Y;

R⁹ is allyl, propargyl or SO2CH3;

Y is OR¹⁸, CO₂R¹⁹, C(O)R¹⁹, CHO, SH, SR²²,

S(O)R²², SO₂NR²⁰R²¹, SO₂N(OCH₃)(CH₃), NHR²³, NR²³R²⁴, p(O)(OR²⁹)₂, CH=NOR²⁵ or

C(R⁴)=NOR²⁵;

R¹⁸ is allyl, propargyl or SO₂ (C₁-C₃ alkyl);

R¹⁹ is C₁-C₄ alkyl substituted with C₁-C₂

alkoxy, C₁-C₂ alkylthio, halogen or NR¹²R¹³;

C₃-C₄ alkenyl; C₃-C₄ alkynyl; CH₂- cyclopropyl; or cyclobutyl;

R²² i_s C₁-C₂ alkyl;

R²⁹ is CH₃;

8. Compounds of Claim 7 wherein

R¹ is C₁-C₂ alkyl;

R² and R⁴ are independently H, Cl, C₁-C₂ alkyl or OCH₃;

R3 and R^~ are independently H or C₁-C₂ alkyl; R⁶ is H or C₁-C₂ alkyl;

R⁷ and R⁸ are independently H or C₁-C₃ alkyl.

9. Compounds of Claim 8 wherein

Q is CH₂W;

W is phenyl optionally substituted by 1-2

substituents selected from halogen and CH₃; tetrahydropyran; tetrahydrofuran; thiophene optionally substituted with Cl or Br; or pyridine.

10. Compounds of Claim 9 wherein

X¹ and X² are CR⁴R⁵Y;

Y is OR¹⁸;

R² and R⁴ are indepedently H, Cl or CH₃;

R³ and R⁵ are independently H or CH₃;

R¹⁸ is propargyl or SO₂CH₃.

11. The compound of Claim 1 which is methyl exo-4- ethyl-α,α-dimethyl-3-(phenyl-methoxy)-7-oxabicyclo- [2.2.1]heptane-1-acetate.

12. The compound of Claim 1 which is methyl exo-4- ethyl-3-[(2-fluorophenyl)-methoxy]-α,α-dimethyl-7- oxabicyclo[2.2.1]-heptane-1-acetate.

13. The compound of Claim 1 which is methyl (exo)- 4-ethy-α-methyl-3-(phenylmethoxy)-7-oxabicyclo- [2.2.1]heptane-1-acetate. 14. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 1 and at least one of the following: surfactant, solid diluent or liquid diluent.

15. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 2 and at least one of the following: surfactant, solid diluent or liquid diluent.

16. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 3 and at least one of the following: surfactant, solid diluent or liquid diluent.

17. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 4 and at least one of the following: surfactant, solid diluent or liquid diluent. 18. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 5 and at least one of the following: surfactant, solid diluent or liquid diluent.

19. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 6 and at least one of the following: surfactant, solid diluent or liquid diluent.

20. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 7 and at least one of the following: surfactant, solid diluent or liquid diluent.

21. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 9 and at least one of the following: surfactant, solid diluent or liquid diluent.

22. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 9 and at least one of the following: surfactant, solid diluent or liquid diluent.

23. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 10 and at least one of the following: surfactant, solid diluent or liquid diluent.

24. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 11 and at least one of the following: surfactant, solid diluent or liquid diluent.

25. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 12 and at least one of the following: surfactant, solid diluent or liquid diluent . 26. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the compound of Claim 13 and at least one of the following: surfactant, solid diluent or liquid diluent.

27. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 1.

28. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 2. 29. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 3.

30. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 4.

31. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 5.

32. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 6.

33. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 7. 34. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 8.

35. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 9.

36. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 10. 37. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 11.

38. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 12.

39. A method for controlling the growth of desired vegetation which comprises applying to the locus to be protected an effective amount of a compound of Claim 13.