CA2125074A1 - Process for preparing organic carbamates - Google Patents

Abstract

PROCESS FOR PREPARING ORGANIC CARBAMATES

Abstract A process has been found for preparing organic carbamates from a basic amine, carbon dioxide and an alkylating agent, characterized in that the amine is firstreacted with carbon dioxide in the presence of one or more basic compounds of the elements lithium, sodium, magnesium, potassium, rubidium, strontium, caesium, barium and/or of ammonium and the alkylating agent then added.

Description

2~2~074 Gai/m-p514E

PROCESS FOR PREPARING ORGANIC CARBAMATES

The present invention relates to a particularly advantageous and easily to be carried out process for preparing organic carbamates from amines, carbon dioxide5 and an alkylating agent.

It is known that diethylamine can be converted to carbarnates by means of alkyl halides rmder CO2 pressure (see for example Chem. Letters 1984, 1571-1572).
Suitable reaction conditions are, for example, 40 atm pressure, 70C and 48 hours reaction time. Yields are in the range from 6 to 53%. Disadvantages are the 10 expense of working under pressure, the long reaction times and the often onlysmall to very small yields. In Bull. Chem. Soc. Jap. 62, 1534 (1989) it is stated that in this method use of more than 5% by weight of solvent (for instance dimethylformamide or dimethyl sulphoxide) leads to losses in yield.

The reaction of a weakly acid amine (= 2-alkylindole) with n-butyllithium and 15 carbon dioxide gives the corresponding lithium carbamate, which can be alkylated in the amine part, but not in the carbamate group, by alkylting agents in the presence of a s~rong organic base (= tSbutyllithium) (see for example J. Am Chem. Soc. 108, 6808-6809 (1986)). This is accordingly not a process for preparing organic carbamates, but for alkylating carbamates in the arnine part.

20 Other a,~-unsaturated, i.e. weakly acidic (= electrophilic) arnines, their metal salts and the metal carbamates obtainable from them, can be converted to organic carbamates without catalysts or with basic catalysts (see for exarnple US-A

3,147,262, US-A.3,299,076, FR-A-2 444 030 and J. Org. Chem. 54, 2425 (1989)).

Those skilled in the art would rule out the applicability of such reactions of 25 weakly acid amines to typical basic and nucleophilic amines, since, taking into account J. Am. Chem. Soc. 108, 6808-6809 (1986) (see above) and J. Chem. Soc.
Chem. Commun., 1979, 797, alkylation is expected in the amine part and not in the carbamate group.

Le A 29 700-FC - 1 -~ 212~07~
There are also processes for preparing organic carbamates from amines, carbon dioxide and alkylating agents or from metal carbamates and alkylating agents, inwhich environmentally unfriendly and/or costly compounds must be used, such as silver carbamates, zinc alkyls, palladium compounds and crown ethers (see for example, Japanese Published Specification 49-81371), Japanese Published Specification 51-113852, Bull. Chem. Soc. Japan 61, 2613 (198~), J. Chem. Soc.
Dalton Trans. 1989, 1007 and EP-A 477 159). Such processes are not very suitable for commercial application.

Finally, the preparation of organic carbamtes from amines, carbon dioxide and alkyl halides in the presence of stoichiometric or excess amounts of strong organic bases, for example diazabicyclo(5.Dr.0)-undec-7-ene (= DBU), has also become known (see for example EP-A 511 948), Chemistry Express 1, 224 (1986)). The large amounts of organic bases required, which are expensive to prepare, difficult to separate and difficult to dispose of, the use of specific solvents and the extensive exclusion of water make this process also unattractive for commercial application. Furthermore, strong bases such as DBU tend to give a multiplicity of ~ -. r reactions, for example eliminations, which increases $he probability of forming by-products (Oediger et al., Synthesis 1972, 591).

In EP-A 511 948 it is specifically indicated that good yields are only obtained with large excesses of alkyl halides. This is naturally very disadvantageous from an economic point of view. -The catalytically forced addition of alkenes, alkines, carbon dioxide and amines to form carbamates is likewise known (J. Molecular Catalysis 74, 97 (1992)).
However the alkylating agents used here have their functionality altered, which is .
25 not the case in this invention.

A process has been found for preparing organic carbamates from a basic amine, carbon dioxide and an alkylating agent, which is characterized in that the amine is first reacted with carbon dioxide in the presence of one or more basic compoundsof the elements lithium, sodium, magnesium, potassium, calcium, rubidium, 30 strontium, caesium, barium and/or of ammonium and the alkylating agent then added.

Le A 29 700-~C - 2 -.... . ,. ~ ~.

. j,,,,,, . , . ,: : - ~ . .

r' 212~074 In the process of the invention a wide variety of basic amines can be used, for example those of the formula (I) ~/R3~
N--~A I A\ I (I), ~R2~ ~ R4J
mn in which 5 Rl, R2, R3 and R4 are the same or di~ferent and each r~present hydrogen or one of the following radicals in monovalent form: Cl-C30-alkyl, C3-C30-alkenyl, C3-C30-alkinyl, C3-CI2-cycloalkyl, C5-CI2-cycloalkenyl, C8-CI2-cycloalkinyl, C6-CI4-aryl, Cs-CI3-hetaryl having up 3 oxygen, sulphur and/or nitrogen atoms in the ring system, C7-C20-aralkyl, C9-C20-aralkenyl, Cg-C20-aralkinyl, C7-C20-alkaryl, C8-C20-10 alkenearyl or C8-C20-alkinearyl, which can optionally be substituted from one to five times by O-C1-CI2-alkyl or -C6-C10-aryl, NH2, NH-C~-CI2-alkyl or -C6-C1O-aryl, N(CI-Cl2-alkyl or -C6-C10-aryl)2, COO-CI-CI2-alkyl or COO-C6-C1O-aryl, CON~I2, CONH-CI-CI2-alkyl, CON(CI-CI2-alkyl)2, halogen, OP(O-CI-CI2-alkyl or -C6-CIO-aryl)2, Si(CI-Cl2-15 alkyl and/or C6-C10-aryl)3~ Si(O-CI-Cl2-alkyl and/or C6-C10-aryl~3~ Si(CI-Cl2-alkyl or -C6-CIO-aryl)(O-Cl-Cl2-alkyl and/or O-C6-CIO-aryl)2, Si(CI-Cl2-alkyl and/or C6-C10-aryl)2(O-Cl-Cl2-alkyl or O-C6-C10-aryl), OS(CI-Cl2-alkyl or C6-C1O-aryl),O2S(CI-Cl2-alkyl or C6-C1O-aryl), CHO, CN, C(O-CI-Cl2-alkyl or -C6-C1O-aryl)2, OC(CI-Cl2-alkyl or C6-CIO-aryl), N~2, CF3, OCF2H, OC~H2, OCF2CF3 20 OCH2Cl~3, OCO(CI-CI2-alkyl or C6-C1O-aryl), HNCO(CI-CI2-alkyl or C6-C1o-aryl), OP(CI-CI2-alkyl or C6-C10-aryl)3, OP(O-(: I-C10-alkyl or -C6-C]O-aryl)2 (Cl-CI2-alkyl or C6-C10-aryl) and/or can optionally be interrupted by oxygen or sulphur atoms or by ~(CI-C12-alkyl or C6-C10-aryl) groups, 25 where Rl and R2 or R3 and R4, in each case together, can also be one of the above-defined radicals, albeit then in divalent form, Le A 29 700-:E~C- 3 -~,,,. .,.; . . ~. ~, . . . I , .
" ,, .",, , ,: . :: ., . , ,: . .. . . . .
,~,:... . ..... : .. . . . . . . : ... . . ~ , . . .
~f, :* , . -~ i... , -.. ~ , . .. . . . .. . . .
,"~, . . ,, , - " , .. : . ,: ". .: :, .. ., . .~

:-~`` 2125~17~
or R3 and R4 can together be a from 3- to 10-membered alkyl ring, which can optionally be substituted with one or two Cl-C10-alkyl groups and/or optionally be interrupted by one or two oxygen, sulphur and/or nitrogen atoms, A is hydrogen or a radical as defined for Rl, although in divalent form, 5 m is zero or an integer from 10 to 10 and n is an integer from 1 to 10, with the provisos that a) Rl~ R2' R3 and R4 are not radicals which contain an isolated a"B multiple ~ :
bond, . .

10 b) in the case of m ~ zero, at least one of the radicals Rl, R2, R3 and R4 is hydrogen, c) in the case of A = hydrogen, m is zero and d) in the case of A = hydrogen, Rl and R2 are not simultaneously hydrogen. : ;
The proviso a) essentially excludes enamines. :

15 Some, not exhaustively listed examples of alkyl groups, including those in compound radicals, are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl and hexadecyl, which can each be straight-chain or branched and/or optionally be substituted byfluorine.

20 Some, not exhaustively listed exarnples of alkoxy groups, including those in compound radicals, are methoxy, ethoxy, propyloxy, butyloxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecylo~y and dodecyloxy, which can each be straight-chain or branched and/or optionally be substituted byfluorine Le A 29 700-~C - 4 -. i ~ ' ~ ! ' ' ' ~ ' ' ,f,r~",. . ,,, .. ," ~

212~74 Halogene means fluorine, chlorine, bromine or iodine.

Some, not exhaustively listed examples of hetaryl groups are pyrazolyl, imidazolyl, 1,2,4-triazolyl, pyrrolyl, furanyl, thienyl, thiazolyl, oxazolyl, pyridinyl, pyrimidinyl, triazinyl, quinolinyl, isoquinolinyl, quinazolinyl, indolyl, ben~o-thienyl, benzofuranyl, benzothiazolyl, benzimidazolyl, pyrazolylmethyl, imidazolyl-methyl, 1,2,4-triazolylmethyl, pyrrolylmethyl, furJ~uryl, thienylmethyl, thiazolyl-methyl, oxazolylmethyl, pyridinylmethyl, pyrimidinylmethyl, triazinylmethyl, quinolinylmethyl, isoquinolinylmethyl, quinazolinylmethyl, indolylmethyl, benzo-thienylmethyl, benzofurfuryl, benzothiazolylmethyl or benzimidazolylmethyl, where optionally each of these groups can be mono- to trisubstituted by the sameor different substituents, for example by fluorine, chlorine, bromine, methyl, ethyl and/or tert.-butyl.

The process of the invention can also be carried out using polyamines which contain, for example, 21 to 500,000 N / -groups where at least one of these groups Rl is hydrogen and Rl and R2 are otherwise asdeflned in formula (I), but where Rl and R2 cannot together be a divalent radical.
Such polyamines can, for example, have molecular weights of from 500 to 3,500,000.

Preferred amines are those of the formula (I) in which Rl, R2, R3 and R4 are thesame or different and are each hydrogen or one of the following radicals in monovalent form:

Cl-CI4-alkyl, C3-C10-alkenyl, C3-C10-alkinyl, C3-CI2-cycloalkyl, C5-C7-cycloalkenyl, C6-C10-aryl, C5-C10-hetaryl having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system C7-Cl2-aralkyl or C7-C10-alkaryl, which can optionally be substituted one to five times by O-CI-C6-alkyl or -C6-C10-aryl, N~I2, NH-CI-C6-alkyl or -C6-C1O-aryl, N(CI-C6-alkyl or -C6-C1O-aryl)2, COO-Cl-C6-alkyl, COO-C6-C10-aryl, CONH-CI-C6-alkyl, CON(CI-C6-alkyl)2, Le A 29 700-FC - S -~.;. . . .. . .

,~: . .. . ..

- 2~ 2~74 OS(CI-C6-alkyl or phenyl), O2S(Cl-C6-alkyl or phenyl), CHO, CN, OC(CI-C6-alkyl or phenyl), NO2, CF3, OCF3, OCF2H, OCFH2, OCO-(CI-C6-alkyl or phenyl) or HNCOICI-C6-alkyl or phenyl), and/or can optionally be interrupted by oxygen or sulphur atoms or by N(C~ 6-S alkyl or phenyl) groups, where Rl and R2 or R3 and R4 in each case together, can also be one of the above-defined radicals, albeit then in divalent form, or R3 and R4 can together be a from 5- to 7-membered alkyl ring, which can optionally be substituted with one or two Cl-C6-alkyl groups and/or optionally be 10 interrupted by an oxygen or sulphur atom or an N(CI-C6-alkyl or phenyl) group, A is hydrogen or a radical defined as preferred for Rl, in divalent form, m is zero or an integer from 1 to 5 and n is an integer from 1 to 5, with the provisos that 15 a') Rl, R2, R3 and R4 are not radicals which contain an isolated a"B multiple bond, b') in the case of m .i zero, at least one of the radicals Rl, R2 R3 and R4 is hydrogen, c') in the case of A -- hydrogen, m is zero and 20 d') in the case of A = hydrogen, Rl and R2 are not simultaneously hydrogen.

Particularly preferred amines are those of the forrnula (I) in which Rl, R2, R3 and R4 are the same or different and are each hydrogen or one of the following radicals in monovalent ~orm:

Le A 29 ~00-FC - 6 -i'' i ":, 21'~74 methyl, ethyl, n-propyl, i-propyl, butyl, cyclohexyl, phenyl, pyrazolyl, imidazolyl, pyrrolyl, furanyl, thienyl, pyridinyl, quinolinyl, isoquinolinyl, quinazolyl, indolyl, benzyl, tolyl and xylyl, which can optionally be mono- or disubstituted by methoxy, ethoxy, phenyl, C~IO,5 CN, carboxymethyl, carboxyethyl, ~:)CF3, OCF2H or NO2, which can optionally be interrupted once or twice by an oxygen atom or an N-methyl, N-ethyl or N-phenyl group, where Rl and R2 can together also be one of the above-defined particularly preferred radicals, although in divalent form, 10 A is hydrogen or one of the particularly preferred radicals as defined for R
although in divalent form, m is zero, 1 or 2 and nislor2, with the provisos as given above for the preferred amines.

15 Some individual amines are~
dimethylamine, diethylamine, di-n-propylarnine, di-i-propylamine, di n-butylamine, di-i-butylamine, di-s-butylamine, di-t-butylamine, di-n-pentylamine, diamylamine, di-i-amylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, di-decylamine, diundecylamine, didodecylamine, ditridecylamine, ditetradecylamine, 20 dipentadecylamine, dihexadecylamine, diheptadecylamine, dioctadecylamine, di-cyclohexylamine, dibenzylamine, diphenylamine, diallylarnine, N-methylaniline, N-ethylaniline, N-propylaniline, N-cyclohexylaniline, morpholine, 3,5 dimethyl-morpholine, piperidine, pyrrolidine, thiomorpholine, N-methylpiperazine, N ethyl-piperazine, tetrahydroisoquinoline 4-piperidone, and the methyl, benzyl and ethyl 25 esters of the following amino acids: alanine, arginine, asparagine, aspartic acid, cysteine, pipecotinic acid, nipecotinic acid, isonipecotinic acid, 4-piperidone-3-carbonic acid, as well as compounds of similar structure of the last example given in EP 541,407 or TAN-amines (see EP 511,948), Le A 29 700-FC - 7 -~ 2~2~7~

glutamine, glutamic acid~ glycine, histidine, isoleucine, leucine, Iysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, t-butylglycine, ornithine, norleucine and sarcosine.

The carbon dioxide used in the process of the invention can be the usual S commercial product, optionally also so-called dry ice. Isotopically enriched carbon dioxide, for example containing 13C and/or 14C, can also be used, in particular for specific purposes, such as analytical or diagnostic applications or where the products which can be prepared are to be used in such applications.

A wide variety of alkylating agents can be used in the process of the invention,10 for example compounds of the formula (II) (R7-Z)o X R B (II), \ (R6_y) in which R5, R6 and R7 are the sarne or different and are each one of the following radicals in divalent form: Cl-C30-alkyl, C4-CI2-cycloalkyl, C3-C30-alkenyl, Cs-CI2-cyclo-alkenyl, C3-C30-alkinyl, C~-CI2-cycloalkinyl, C7-C20-aralkyl, C8-C20-aralkenyl, C8-C20-aralkinyl, C8-C20-alkenaryl, C8-C20-alkinaryl, Cs-CI3-alkenehetaryl or Cs-CI3-alkinehetaryl, the latter two each having up to 3 oxygen, sulphur andtor nitrogen atoms in the ring system, where chains in the molecules can be linear, branched and/or optionally interrupted by oxygen, sulphur, N(CI-Cl2 or C6-C10-aryl), CO, COO, SO, SO2 or SO(O)O or OP(CI-Cl2-alkyl or C6-C10-aryl) groups, where the groups R6-Y and R7-Z can also be hydrogen and in this case lR5 can optionally be additionally substituted by COO(CI-Cl2-alkyl or C6-C10-aryl), O-C(O)-(CI-Cl2-alkyl or C6-C10-aryl), CON(CI-Cl2-alkyl or C6~C10-aryl)2, (CH2-O-(-C(O) Cl-CI2 alkyl or C6-C10 aryl), C6-C10-aryl, Cs-CIl-hetaryl having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system, O(CI-Cl2-alkylor C6-C10-aryl), N(CI-Cl2-alkyl or C~-C10-aryl)2, OP(OC-CI-Cl2-alkyl or C6-C10-Le A 29 700-FC - 8 --` 21~507~
aryl)2, Si(O-Cl-C12-alkyl or -C6-CI0-aryl)3, Si(Cl-Cl2-alkyl or C6-Cl0-aryl)3 orhalogen, o and p independently of one another are each zero or 1, B is not present if o = p = zero, in the case of p= 1 and o= zero, B is one of the following radicals in divalent form: CH2, N(Cl-Cl2-alkyl or C6-C10-aryl), OP(CI-Cl2-alkyl or C6-CI0-aryl), phenyl, naphthyl, (CH2)q with q = 2 to 30 or (CH2),-M-(CH2)S with r and s being the same or different and each = 1 to 20 and M= an oxygen or sulphur atom or an SO2 or N(Cl-Cl2-alkyl or C6-CI0-aryl) group, in the case of p= 1 and o= 1, B is one of the following radicals in trivalent form: CH, N, (O)P, phenyl or naphthyl and -~

X, Y and Z independently of one another are each a leaving group.

Alkene and alkine radicals may be once or several times unsaturated.

Suitable leaving groups X, Y and Z are, for example, halogen such as fluorine, chlorine, bromine and iodine, sulphonate such as aryl- and perfluoroalkyl-sulphonate, monosubstituted diazo and monosubstituted nitrato, and those addition-ally given in J. March, Advanced Organic Chemistry, 3rd Ed., John Wiley &
Sons, New York 1985, pp. 310-316. Chloromethylated aromatic polymers, such as chloromethylpolystyrene, having molecular weights of, for exarnple, from 1000 to1,000,000 are also suitable.

Preferred alkylating agents of the formula (II) are those in which R5, R6 and R7are the same or differeint and are each one of the following radicals in divalent form: C]-C20-alkyl, C5-C8-cycloalkyl, C3-C10-alkenyl, C5-C8-cycloalkenyl, C3-CIo-alkinyl, C7-CI4-aralkyl, C8-Cls-aralkenyl, C8-CIs~aralkinyl, C8-CI~-alkenaryl, C5-CI0-alkenehetaryl or C5-CI0-alkinehetaryl, the latter two having each up to 2sulphur and/or nitrogen atoms in the ring system, Le A 29 700-lFC - 9 -;, , ~ ,~ ., . .~, . . . , . . ~

~ 2~2~07~
. . .
where chains in the molecules can be linear, branched and/or optionally interrupted by oxygen, sulphur, N(CI-Cl2-alkyl or C6-C10-a~yl), CO, SO or SO2 groups, where the groups R6-Y and R7-Z can also be hydrogen and in this case ~5 can S optionally be additionally substituted by COO(CI-C6-alkyl or phenyl), -O-C(O~-CI-C8-alkyl), CON(CI-C6-alkyl~, C6-C1O-aryl, CH2-O-(-C(O)-CI-CI2-allyl), C5-C8-heta~yl having up to 2 sulphur and/or nitrogen atoms in the ring system, OCI-C6-alkyl, N-CI-C6-alkyl or halogen, B is not present if o = p = zero, in the case of p= 1 and o= zero, B is one of the following radicals in divalent form: CH2, N(CI-C6)-alkyl or phenyl), phenyl, naphthyl, (CH2)q with q = 2 to 10 or (CH2),-M-(CH2)s with r and s being the same or different and each= 1 to 10 and M = an oxygen or sulphur atom or an SO2 or N(CI-C6-alkyl or phenyl) group, in the case of p = 1 and o = 1, B is as defined above and X, Y and Z independently of one anothel are each a leaving group.

Possible alkylating agents include tri(CI-Cl2-alkyl) phosphites and also acetates and aminal esters of dimethylformamide, each having a total of up to 10 carbon atoms.

Possible alkylation agents include further:

a-D-Glucopyranosyl bromide tetra acetate, a-D-Glucopyranosyl bromide tetra benzoate, 2,3,4-Tri-o-acetyl-a-D-xylopyranosyl bromide, 2,3,4,6-Tetra-o-acetyl-a-D-xylopyranosyl bromide, 2,3,4,6-Tetra-o-acetyl-oc-D-glucopyranosyl bromide, Methyl-2,3,4-tri-o-acetyl-1-bromo-1-deoxy-a-D-glucopyranuronate, a-D-C;alactopyranosyl bromide tetraacetate, Acetobromo-a-D-galactose, 2,3,4,6-tetra-o-acetyl-oc D-galactopyranosyl bromide, Le A 29 700-FC - 10 -212~7~
Methyl-(2,3,4-tri-o-acetyl-c~-D-glucopyranosyl-bromide)-uronate, I-a-bromo gluconic acid 2,3,4-tri-o-acetyl methylester, 1-a-bromo gluconic acid 2,3,4-tri-o-acetyl ethylester, Acetobromo cellobiose, 5 a-bromo hepta-o-acetyl maltose and 2,3,6-tri-o-acetyl-4-o(2,3,4,6-tetra-O-acetyl-oc-D-glucopyranosyl) glucosyl bromide or similar halogen/oxygen acetals which are described in Houben-Weyl, Methoden der Organischen Chemie, Band E14a/3, page 1-136 and 621-1075 as well as halogen/sulfur or halogen/nitrogen acetals, described on pages 142-202 and 203-10 620.

In addition to these reagents suitable for the claimed reaction one can prepare C-(3)-chloro (or bromo or iodo)-1,3-dihydro-2H-1,4-benzodiazepin-2-ones as given in Kovac et al., 3. Heterocyclic Chem. ~, 1449 (1979), p. 1452 method A or B and react these with CO2 and amines as claimed to yield, e.g. Camazeparn (= dimethyl15 carbamic acid 7-chloro-2,3 -dihydro- l -methyl-2-oxo-5 -phenyl- l H-benzodiazepin-3 -yl ester (see Merck Index 11th ed., 1732).

Particularly preferred alkylating agents are those of the formula (III) X - Rs (III), in which 20 Rs is one of the following radicals in monovalent form: Cl-C20-alkyl, C4-CI2-cyc-loalkyl, C3-C30-alkinyl, C7-C20-aralkyl, C8-C20-aralkenyl, C8-C20-alkenaryl, C8-C20-alkinaryl, Cs-CI3-alkenehetaryl or Cs-CI3-alkinehetaryl, the latter two each having up to 2 oxygen, sulphur and/or nitrogen atoms in the ring system and X isa leaving group, and also the following individual compounds:

25 The bromides, iodides, toluenesulphonates and mesylates of the following radicals:
methyl, ethyl, propyl, i-propyl, allyl, n-butyl, i-butyl, s-butyl, t-butyl, pentyl, he~yl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, docosyl, tricosyl, cyclopropylmethyl chloride, cyclopropylmethyl mesylate, benzyl chloride, benæyl bromide, benzyl 30 iodide, benzyl p-tolylsulphonate, benzyl mesylate, 2-(chloromethyl)-naphthalene, 3-(chloromethyl)-naphthalene, the chloride, toluene sulphonate and mesitylate of 9- `
Le ~ 29 700-FC - 11 -f~

" ~ , , -- 2~2~07~
fluorenylmethyl, cinnamyl chloride, p-methoxybenzyl chloride, rn- and p-nitro-benzyl chloride, p-bromobenzyl chloride, o-, m- and p-chlorobenzyl chloride, 9-anthrylmethyl chloride, methyl chloromethyl ether, ethyl chloromethyl ether, butyl chloromethyl ether, octyl chloromethyl ether, N-chloromethylphthalimide, 2,2,2-5 trichloro-1,1,1-dimethylethyl chloride,o-, m- and p-chloromethylbenzyl chloride, monochloroacetone, ethyl chloromethyl ketone, propyl chloromethyl ketone, phenyl chloromethyl ketone, p-nitrophenyl chloromethyl ketone, methyl and ethyl chloroacetate, methyl and ethyl bromoacetate, p-(chloromethyl)-polystyrene, Merrifield's peptide resins, t-butyl 4-chloroacetoacetate, 2,3-, 2,4-, 2,5- 2,6- and 10 3,4-dichlorobenzyl chloride, (3-chloropropyl)-4-methylpiperazine, 1,2-dichloro-ethane, 1,3-dichloropropane, 1,4-dichlorobutane, 1,5-dichloropentane, dichloro-methyl ether, 2,4-dichloro-2-butene, 1,4-dichloro-2-butine, di-(1-chloroethyl) thio-ether, chloromethyl t-butyl ketone, 3-(chloromethyl)-heptane7 chloroacetonitrile, 4-chlorobutyronitrile, chloroacetaldehyde, epichlorohydrin, isoamyl chloride, 6-15 chlorohexyl isocyanate, 2-isocyanatobenzyl chloride, triethoxychloromethylsilane, methyl and ethyl 1-chloropropionate, crotyl chloride, 1-dimethylamino-2-chloro-ethane, 1,2-dichloro-2-propene, 1-chloro-2-methyl-2-propene, chloroacetarnidoben-zene, 1-chloroacetamido-4-chlorobenzene, N,N-diethylchloroacetarnide, 2-chloro-ethyl p-chlorophenyl ketone, methyl, ethyl, propyl, n-butyl and t-butyl esters of 2-20 or 4-chloroacetic acid, a-2,4-trichloroacetophenone, chloromethyl phenyl and tolyl sulphone, 3-chloropentane dione, diethyl chloroacetamide, dimethyl-2-chloro-acetamide, ethyl-o~-chlorophenylacetate, 2-chloro-malonic acid diethyl ester and 2-chloro-malonic acid dimethylester. Also methylene chloride, methylene bromide and chloro-bomo-methane are suitable alkylating agents.

25 Particularly preferred sulphonate radicals X, Y and Z are p-toluenesulphonate, p-bromobenzenesulphonate, p-chlorobenzenesulphonate, p-nitrobenzenesulphonate, methanesulphonate, trifluoromethanesulphonate, nonafluorobutanesulphonate, 2,2,2-trifluoroethanesulphonate and benzalsulphonate.

Alkylating agents containing sulphonate groups can, like other alkylating agents30 mentioned, be prepared separately and used as such in the process of the invention. The alkylating agents needed can also be prepared in situ, alkylatingagents containing sulphonato groups for e~ample from alcohols and halogenosulphorlyl compounds.
:; , Le A 29 700-FC - 12 -,,,~", , . ~ , , , , . ~ .

' 212~07~
In the process of the invention, for example, from 0.01 to 10,000 equivalents ofcarbon dioxide can be used per equivalent of amine used. Preferably this ratio is from 0.5 to 1,000:1, in particular from I to 10:1.

In the process of the invention, for example, from 0.01 to 10,000 equivalents of5 alkylating agent can be used per equivalent of amine used. Preferably this ra$io is from 0.3 to 100:1, in par$icular from 0.4 to 10:1. The alkylating agent can be used ~ ' in a substantial excess, particularly in the case of lesse reactive alkylating agents, and can then optionally also serve as solvent.

It is an essential feature of the present invention that it is carried out in the 10 presence of one or more basic compounds of the elements lithium, sodium, magnesium, potassium, calcium, rubidium, strontium, caesium, barium and/or of ammonium. Possible basic compounds are, for example, basic salts, oxides, hydrides and hydroxides. Examples are: lithium hydride, sodium hydride, potassium hydride, calcium hydride, lithium hydroxide, sodium hydroxide, l S potassium hydroxide, strontium hydroxide, barium hydroxide, lithium oxide, sodium peroxide, potassium oxide, potassium peroxide, calcium oxide, barium oxide, magnesium oxide, strontium oxide, lithium carbonate, lithium hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, rubidium carbonate, rubidium hydrogen carbonate, 20 caesium hydrogen carbonate, caesium carbonate, lithium cyanide, sodium cyanide, potassium cyanide, rubidium cyanide, ammonium hydrogen carbonate, ammonium carbonate, ammonium carbama$e, potassium sulphite, potassium hydrogen sulphide, sodium sulphide, sodium hydrogen sulphide and/or naturally occurring or synthetic mixtures containing them, such as for example dolomite or magnesium 25 oxycarbonate and/or compounds which contain sodium or potassium metal in dispersed form on the corresponding carbonates.

Preferred compounds are alkali metal carbonates and/or hydrogen carbonates, verypar$icular preference being given to potassium carbonate. ...

The basic compounds"'c~an be used in anhydrous form or, as far as salts which 30 crystallize with water of hydration are concerned, in hydrated form. Use of anhydrous compounds is preferred. .

Le A 29 700-~C - 13 --` 212507~
The basic compounds can, for example, be used in amounts of from 0.5 to 10 mol per mole of amine used. Preferably this amount is in the range from 0.8 to 5 mol, particularly preferably in the range from I to 2.5 mol, in each case p~r mole ofamine used.

5 The process of the invention can optionally be carried out in the presence of auxiliary bases, i.e. in the presence of further bases, for example in an amount of less than 0.5 mol, with respect to the base used.

Examples of such auxiliary bases are: halides of alkali metals, zeolites, potassium acetate, potassium formate, sodium acetate, titanium alkoxides, titanic amides, arnidine bases or guanidine bases such as 1,5-diazabicyclo(4.3.0)non-5-ene ~DBN), 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU), 7-methyl-1,5,7-triazabicyclo(4.4.0)dec-5-ene (MTBD), cyclohexyl-tetrabutylguanidine, cyclohexyl-tetram~thylguanidine, N,N,N,N-tetramethyl-1,8-naphthalenediamine, pentamethylpiperidine, N,N-di-methyl-aminopyridine, N-butyl-tetraethylguanidine, N-t-butyl-N'-N'-diethylform-15 amidine, tetrarnethylguanidine, tetraethylguanidine, N-t-butyl-N',N'-dimethylacet-amidine, N-cyclohexyl-tetraethylguanidine and N-t-butyl-tetraethylguanidine and also 1,4-diazabicyclo(2.2.2)octane (DABCO), tertiary amines such as triethyl-amine, trimethylamine, N-methylmorpholine, pyridine and tetramethylethylene-diamine, primary and secondary amines having the same structure as the arnine 20 used in the reaction, alkyl and aryl metal compounds such as butyl~, methyl-, phenyl- and neophyl-lithium, and also Grignard reagents.

In general, it is advantageous to carry out the process of the invention in the presence of solvents. Solvents are advantageously used in such an amount that the reaction mixture remains readily stirrable during the whole process. Possible 25 solvents are, for example: hydrocarbons such as petroleum ether, benzene, toluene, chlorobenzene, dichlorobenzene, hexane, cyclohexane, methylcyclohexane, pentane, heptane, octane and industrial hydrocarbon mixtures, for example so-called white spirits containing components with boiling points in the range of, for example, from 40 to 250C~, ethers such as dimethyl, diethyl, dipropyl, diisopropyl, 30 dibutyl, methyl t-butyl ether, tetrahydrofuran, 1,4-dioxane and polyethers ofethylene oxide and/or propylene oxide, amines such as trimethyl-, triethyl-, tripropyl-, tributylamine, N-methylmorpholine, pyridine and tetramethylethylenedi-amine, esters such as methyl, ethyl and butyl acetate, and also dimethyl, dibutyl Le A 29 700-FC - 14 -r~,~ - . .

~/" .

212~7A
-and ethylene carbonate, nitro-compounds such as nitromethane, nitroethane, nitropropane and nitrobenzene, nitriles such as acetonitrile, propionitrile and benzonitrile and also compounds such as tetrahydrothiophene dioxide and dimethylsulphoxide, tetramethylene sulphoxide, dipropyl sulphoxide, benzylmethyl 5 sulphoxide, diisobutyl sulphoxide, dibutyl sulphoxide, diiosamyl sulphoxide, ketones such as acetone, methyl butyl ketone and methyl ethyl ketone, liquefied carbon dioxide, amides such as hexamethylenephosphoric triarnide, N-methyl-pyrrolidone, N-methylcaprolactam, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimid-ine, octylpyrrolidone, octylcaprolactam, 1,3-dimethyl-2-imidazolinedione, di-10 methylformamide, dimethylacetamide, formamide, diethylformamide, N-formyl-pyrrolidine, N-formylmorpholine, N-formylpiperidine, N,N'-1,~-diformylpipera~ine, dipropylformamide and dibutylformamide. Also suitable are dimethylsulfone, diethylsulfone, dipropylsulfone, dibutylsulfone, dipentylsulfone, dihexylsulfone, methylethylsulfone, ethylpropylsulfone, ethylisobutylsulfone, 3-sulfolane and 1 5 pentamethylenesulfone.

The process of the invention can also be carried out without solvent, particularly when, instead of solvent, auxiliaries suitable for phase transfer reactions are added, for example quaternary ammonium salts, polyvinylpyrrolidone, trioctylphosphine oxide and/or acetylacetone.

20 Auxiliaries such as cryptands, for example crown ethers or polyethers as complexing agents, may optionally be added to the solvents.

Mixtures of solvents can of course also be used in the process of the invention.
Preferred solvents are dimethylformamide and dimethylsulphoxide and mixtures of these with other solvents mentioned.

25 The process of the invention is generally carried out in such a way that the basic amine and the earbon dioxide are first combined in the presence of a basic compound of the elements mentioned and allowed to react. It is advantageous to add the alkylating agent only when the reaction of the amine with the carbon dioxide is complete or largely complete. The progress of the reaction of the amine 30 with the carbon dioxide can be monitored, for example, by the degree of heat evolution.

Le A 29 700-FC - 15 -;,, ~.. ,,. . . . -~, -. ~ . , : . , . :
;,;~,: . , , : : -. ~
",, .. . . , . ,, ,-: . -! ` 2 ~ ~ 5 0 Both steps of the process of the invention can be carried out, for example, at temperatures of from -50 to +180C. Temperatures are preferably in the range from -30~ to +150C, particularly in the range from -10C to -~100C.

The pressure is not critical in the process of the invention. It can in principle be 5 carried out at atmospheric pressure, but increased or reduced pressure is alsopossible. It is preferable to work at atmospheric pressure or at pressures up to15 bar. At higher temperatures it is advantageous to use increased pressure, optionally even above 15 bar.

The process of the invention can be carried out under a carbon dioxide 10 atmosphere, but also in an atmosphere containing carbon dioxide and other, preferably inert, gases. If liqued carbon dioxide is used, then the reaction is preferably carried out in an closed vessel at the autogenous pressure which is developed.

The process of the invention has a number of surprising advantages. It allows the 15 preparation of carbamates in a technically simple, economically advantageous manner, avoiding the use of phosgene, chlorine, formic esters, isocyanates, carbamoyl chlorides and carbonates, which in many cases require very considerable expenditure for plant safety. It can be used to prepare N,N-dialkylated, highly O-reactive alkenes and alkines which are not obtainable, or 20 obtainable only with great difficulty, by other means, such as Bu2N-CO-OCH2-C_C-H (see Exarnple 13). It can be carried out under mild reaction conditions and the reaction mixtures can often be directly used further, for example for hydrogenations, chlorinations, brominations, oxidations, condensations and/or polymerizations.

25 Radioactive or labelled carbon atoms can be simply introduced into organic molecules using the process. If the carbamate produced is to be isolated in pureform, this can likewise be achieved in a simple manner, for example by separating off the mixture of salts present in the reaction mixture, stripping off the readily volatile cornponents of the reaction mixture and then isolating the carbamate, for 30 example by distillation or crystallization. If the reaction mixture contains unreacted amine, this can be removed as described above or by washing with dilute acid, without the carbamate formed being attacked. As the process of the invention Le A 29 700-~C - 16 -~": ~ , ', . , 'I : : .:

,~','~,.'S;'"` ','''.'' ,' ' "' ' ;, ., '', -- 2~2~7~
proceeds in a heterogeneous phase, it is also suitable ~or continuous operation, in which case solvent and base, optionally after regeneration, can then be recycled to the reaction mixb~re. This is particularly convenient ~or the solvent, since it allows direct reuse without introduction of an aqueous phase in the work-up.

5 Carbamates are important substances in the chemical industry which are used, for example, as intermediates -for active ingredients or as active ingredients in plant protection (in particular for insecticides, pesticides, fungicides and herbicides) and in the pharmaceutical area. They can also serve as intermediates for plastics, paints and polymers. Isocyanates can be obtained from carbamates by thermal 10 elimination. The process of the invention can also be applied to the removal of undesired halogen-containing organic materials from waste gases and liquid and solid residues, and also for rendering harmless halogencontaining organic weapons (as mentioned, for example, in Klimmek et al., Chemische Gifte und Kampfstoffe [Chemical Poisons and Weapons], Hippokrates Verlag Stuttgart 1983, p. 2,7 ff.).
15 Examples are the removal of methyl chloride and chlorodimethyl ether from waste gases or the disposal of bromoacetone, bromobutenones, chloroacetophenones, mustard gas and nitrogen mustard.

The process of the invention Gan also be used to protect primary or secondary amines for further reactions, by conversion to carbamates, and afterwards again 20 liberating the primary or secondary amines from these. This protective group technique is particularly important in the area of ~rotein chemistry (see for example T.W. Greene, Protective Groups in Org. Synthesis. Wiley-Interscience, New York 1981, pp. 223-249). Some particularly important carbarnates, which can advantageously be prepared according to the invention, are as follows: 3-methyl-2-25 oxalidone, N-phenyl-carbamic acid, ethyl N-methyl-N-phenylcarbamate, ethyl N-ethyl-N-phenylcarbamate, carbendazim, isopropyl 3-chlorocarbanilate, 4-nitro-phenyl-methylurethane, 1,3-propanediol-2-methylene-bis(methylcarbamate), 2-[(methoxycarbonyl)-methyl-amino]-benzoic acid N-methylisatate, methyl 7-hydroxy-1-naphthalenecarbamate, ethyl diphenylcarbamate, 3-ethoxycarbonyl-30 aminophenyl N-phenylcarbamate, methyl N-[3-[N-(3-methylphenyl)-carbonyl]-phenyl]-carbamate, CH3-N(-CH2CH2-O-CO-N~I-C6H532, N-L-a-aspartyl-L-phe.nyl alanine-1-methylester-N-benzyl carbamate, asparlyl benzylester-N-benzyl carb-amate, aspartyl methylester-N-benzyl carbamate, aspartyl ethylester-N-benzyl carbamate, aspartyl acid-N-benzyl carbamate, and the carbamates mentioned in Le A 29 700-liC - 17 -s~ -~. , .. - - . , , 7 . . ~ ~

K.H. Buechel, Pflanzenschutz und Schadlingsbekampfung [Plant Protection and Pest Control], ~eorg-Thieme-Verlag, Stuttgart, 1977, in the chapters Insecticides, Herbicides, Fungicides, Nematocides, Acaricides and Bactericides, as well as carbamates described in ~P 289,842 and DE 4,026.966.

Also carbamates of the type described in WO 93/7116 and EP 582,902 (see Examples 33 and 45 of the present description) can be produced according to the present invention. The corresponding benzyl compounds with leaving groups as described above and the corresponding amines can be used as educts in this case.
Also carbamates of the type described in EP 560,424 can be produced according to the present invention, especially the compound designated I to 3, 6 to 10, 12and 14 to 17, as well as similar compounds with structures of the carbarnate type as described in EP 560,424. The starting materials then are, ~or example, benzyl or aliphatic compounds with leaving groups as described above and the corresponding amines.

Also carbamates of the type described in EP 335,297 and in EP 3~6,189 and in Keith et al., Spec. Publ. - R. Soc. chem., 119, 79 (1993), and in literature cited there can likewise be prepared. Especially compounds using ciprofloxacin as a starting material, e.g. compoun:l 8 cited in Keith et al., can be prepared easily.
The starting materials are esters of ciprofloxacin or related derivatives of 20 quinolones and cephatosporius in their protected form ~see the literature mentioned above) and with leaving groups as defined above, preferred activated esters as tosyl or mesyl esters.

Carbamates of the type described in U.S. 5,210,224 (antibiotic lankacidines) canalso likewise be prepared. In this case the corresponding mesyl- or tosyl- or other 25 above stated acyl leaving groups are bond to the lankacidine instead of the carbonate group given in U.S. 5,210,224 and is reacted with CO2 and an arnine asdescribed above. The products are the same as given in U.S. 5,210,224 and might be others depending from the amine used.

Le A 29 700-FC - 18 -. ~,. .. .. ~.... " . ~ . , . , - . - - - , - - - -~.,; :~ . . :
', .. .. .

---" 212~0 ~4 Examl)les The bases used in the examples (often potassium carbonate) were dried at 150C
and 15 mbar for 14 hours and powdered. Solvents used (often dimethylformamide or dimethyl sulphoxide) were dried with a molecular sieve of 3 A. All reactions were carried out with a steady slow strearn of carbon dioxide over the reaction mixture.

Example 1 Cinnamyl N-methyl-N-9-fluorenylcarbamate 5.0 g of N-methyl-N-9-fluorenylamine, 20.0 g of potassium carbonate and 100 ml of dimethylformamide (abbreviated to DMF below) were admixed with 40 g of dry ice and after 1 hour at 25C under a carbon dioxide atmosphere 4.69 g of cinnamyl chloride were added. The mixture was stirred for a further 1 hour at 25C and 5 hours at 50C, then separated from the solids, the volatile components were driven off under reduced pressure, the concentrate was extracted with dichloromethane/water and the extract was chromatographed on silica gel with toluene and an increasing ethyl acetate conten~. 4.96 g (54 % of theory) of the desired product having a melting point of from 108 to 109C were obtained. In addition, 0.61 g (8 % of theory) of N-methyl-N-9-fluorenyl-N-cinnamylamine having a melting point of ~rom 85 to 89C were obtained.

E~amPle 2 Cinnamyl N-methyl-N-9-fluorenylcarbamate-l3C

Example 1 was repeated but, instead of using dry ice, l3co2 (produced from barium carbonate-l3C, 88 %, and sulphuric acid) was blown in. The yield was 3.14 g (34 % of theory). The l3C-NMR spectrum showed a great increase in intensity of the carbamate-l3C at r 157-158 ppm Le A 29 700-FC - 19 -~ . ' : ! , , :
~'''' ' ' , .~ ' 2~2507~

4-tert.-Butylbenzyl N-methyl-N-9~fluorenylcarbamate in 100 ml of DMF and 20.0 g of potassium carbonate were admixed with 6.99 g of 4-tert.-butylbenzyl bromide, stirred for 2 hours at 25C and 8 hours at 50C and worked up as described in Example 1. 3.4 g ~38 % of theory) of N-methyl-N-9-fluorenyl-(4-t-butylamine) having a melting point of from 92 to 94C were obtained, and also 4.02 g of an oil which contained about 80 % by weight of the desired material.
The IR spectrum showed a characteristic band (CO bending) at 1,685 cm~l.

E~ample 4 Cinnamyl N-methyl-N-(I-naphthylmethyl)carbarnate ~:

8.5 g of N-methyl-N-(I-naphthylmethyl)-amine (obtained from the hydrochloride .
by shaking with sodium hydroxide, extraction and distillation using a bulb tube), 38.43 g of potassium carbonate and 200 ml of DMF were treated with carbon dioxide gas for 1 hour at 25C, then 8.34 g of cirmamyl chloride were added, themixture was stirred for 1 hour at 25C and 8 hours at 50C and then worked up asdescribed in Exarnple 1. 7.23 g (44 % of theory) of the desired material were obtained (~H: 4.83 ppm, 4.97 ppm). In addition, 0.83 g (6 % of theory) of N-methyl-N-(l-napthylmethyl)-cinnamylamine were isolated.

E~ample 5 Cinnamyl N-methyl-N-phenylcarbamate 5.35 g of N-methylaniline, 38.43 g of potassium carbonate, 200 ml of DM~, ~ed-incarbon dioxide and 8.34 g of cinnamyl chloride were reacted as described in Example 4 and worked up as described in Example 1. The yield of the desired product was 1.61 g (12 % of theory). The lH-NMR and 13C-NMR spectra showed the following characteristic signals: yH: 4.76 and 3.3.2 ppm and ~C: 155.4 ppm.

Le A 29 700-~C - 20 -s~5;~

f'` 2~2~07~
lExample 6 Cinnamyl N,N-dibutylcarbamate 20.0 g of dibutylamine, 37.73 g of potassium carbonate and 100 ml of DMF were treated with carbon dioxide gas (exothermic reaction up to about 45C). 23.64 g of 5 cinnamyl chloride were then added dropwise at 10C and the mixture was stirredfor I hour at 25C and 4 hours at 50C. After working up as described in Example 1, 9.86 g of the desired product and 0.56 g (2 % of theory) of dibutylcinnamylamine were isolated. Characteristic signals in the IH~
spectrum were at 4.73 and 3.23 ppm.

ExamDle 7 ;

Phenylacetyl N,N-dibutylcarbamate 20.0 g of dibutylamine, 37.73 g of potassium carbonate and 100 ml of DM~ were combined as described in Example 6 and treated with carbon dioxide gas for I hour at 25C, then admixed at 10C with 23.95 g of a-chloroacetophenone and the mixture stirred for a further 1 hour at 25C and 4 hours at 50C. The work-up ~: :
proceeded by extraction with 5 % by weight strength aqueous hydrogen chloride and ethyl acetate and distillation in a bulb tube. At a boiling point of 145C at 0.1 mbar 29.1 g of the desired product (62 % of theory) were obtained. The characteristic signals in the IH-NMR spectrum were at 5.31 and 3.28 ppm.

20 Example 8 Example 7 was repeated, but using only half the amount of each material, using dimethyl sulphoxide (abbreviated to DMSO below) instead of DM:F and stirring for 6 hours at 25C. Subsequent gas chromatographic examination of the reaction mixture gave a 98.4 % yield of the desired product based on the conversion.

Le A 29 700-~C - 21 -~:~ 2~177~
Example 9 3-Oxo-2-ketobutyl N,N-dibutylcarbamate ~, The procedure was as in Example 7, but 23.73 g of ethyl bromoacetate were added instead of 2-chloroacetophenone and the mixture was stirred for 1 hour at 25C and 3 hours at 50C. At a boiling point of 100C at 0.1 mbar 5.0 g of the desired product (12 % of theory) were isolated. The characteristic signals in the IH-NMR spectrum were at 4.60, 4.21 and 3.25 ppm.

Example 10 The procedure was as in Example 9, but only half the amount was used and 10 DMSO was used instead of DMF. The yield (gas chromatography, % by area) after 4 hours reaction time was 52 % based on the conversion. The conversion was 90 %.

Example 11 Propargyl N-butylcarbamate 15 30 g of butylamine, 100 g of potassium carbonate and 160 g of DM~ were treated with carbon dioxide gas (exothermic reaction up to 66C). After 1 hour 33.68 g of 3-chloropropine were added at 15C and the mixture stirred for 1 hours at 25C
and 3 hours at 50C. The rnixture was then worked up as described in Example 7.
2.86 g of the desired product (4 % of theory) were obtained.

20 Example 12 5.66 g of butylamine, 18.87 g of potassium carbonate and 50 rnl of DMSO were admixed with 5.77 g of propargyl chloride after treatment for 1 hour with carbondioxide gas at 25C and the mixture was stirred for 4 hours at 25C. Otherwise the procedure was as described in ~xarnple 11. The yield of propargyl N-butyl-25 carbamate was 87 % based on the conversion (gas chromatography, % by area).

Le A 29 700-~C - 22 -i %125074 Exam~e 13 Propargyl N,N-dibutylcarbamate 100 g of dibutylamine, 189.0 g of potassium carbonate and 500 ml of DMF were treated with 440 g of carbon dioxide in a 3 I stainless steel autoclave and subsequently heated to 100C for 30 minutes. After cooling to 50C, 60.0 g of 95 % propargyl chloride were added at a pressure of 75 bar and the temperature maintained at 50C for a further 6 hours. After depressurization the mixture wasfiltered with suction, the filtercake washed with 1 l of methylene chloride and the organic phase distilled. Two fractions containing the desired product were collected. 1st fraction: boiling point from 55 to 95C at from 1.3 to 1.5 mbar:
11.41 g (of which 50 % by weight was the desired product). 2nd fraction: boilingpoint from 97 to 98C at 1.4 mbar: 107.53 g (of which 98.8 % by weight was the desired prod7~ct). This corresponds to a yield of 69.~ % of theory. Characteristic signals in the IH-NMR spectrum were at 4.68, 3.23 and 2.43 ppm.

E~aml~le 14 Butyl N-methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 70 ml of DMSO
were admixed with 7.17 g of butyl chloride after treatment with carbon dioxide gas for 1 hour. After 15 hours at 25C the formation of the desired product in ayield of 42.1 % was determined by gas chromatography. The mass spectrum showed M~ at 207.

Examp!e 15 Benzyl N,N-dibutylcarbamate 10 g of dibutylamine, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour (slightly exothermic reaction). Afteraddition of 9.83 g of benzyl chloride the mixture was stirred for 29 hours at 25C.
Analysis by gas chromatography and mass spectroscopy indicated that the desired Le A 29 700-FC - 23 -2i2~7~
, .. .

product was then present in a 95.5 % yield. M = 263. After working up as in Example 1 18.4 g of product (90 % of theory, 96 % pure) were obtained.
Examnle 16 .
0-[3-Methoxycarbonyl-2~methoxyprop-2-enyl] N,N-dibutylcarbamate 10 g of dibutylamine, 18.87 g of potassium caubonate and 50 ml of DMS0 were treated with carbon dioxide gas for 1 hour (slightly exothermic reaction) and 12.75 g of methyl 4-chloro-3-methoxy-2-butenoate were then added. After stirringfor 45 hours at 25C the desired product was present in the reaction mixture in a yield of 92.4 %, according to gas chromatographic and mass spectroscopic examination. The mixture was filtered with suction and the residue was concentrated with a rotary evaporator, taken up with ethyl acetate and washed with 5 % strength aqueous hydrogen chloride to give 26.75 g of 79.4 % desired product(90.9 % of theory), remainder = dimethyl sulphoxide. The IH-N~ spectrum showed the characteristic signals at 5.23, 5.10 and 3.20 ppm.

Example 17 cis/trans-0-(3-methoxylcarbonylprop-2-enyl) N,N-dibutylcarbamate 10.0 g of dibutylamine, 18.87 g of potassium carbonate and 50 ml of DMS0 were treated with carbon dioxide gas for I hour (~xothermic reaction). 16.32 g of methyl 4-bromocrotonate (85 %) were then added. After stirring for 45 hours at 25C the desired product was found in a yield of 23.8 % of theory, according to gas chromatographic and mass spectroscopic analysis. M~ = 271, cis/trans mixtureabout 1:2.

E2~arnl~le 18 Tributyl carbamate lO.0 g of dibutylamine, 18.87 g of potassium carbonate and 50 ml of DMS0 were treated with carbon dioxide gas for 1 hour at 25C (exothermic reaction). After addition of 10.62 g of butyl bromide and stirring for 45 hours at 25C the desired Le A 29 700-FC - 24 -2~074 product was found in an amount of 76.0 % of theory, according to gas chromato-graphic and mass spectroscopic analysis. M+ = 229.

Example 19 .
Benzyl N-butylcarbamate 5.66 g of butylamine, 18.87 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour at 25C. After addition of 9.81 g of benzyl chloride and stirring for 45 hours at 25C gas chromatography and mass spectrometry showed the desired product to be present in a yield of 87.2 % of theory, based on a conversion of 78 %. M~ = 207. After working up as described in Exarnple 16, 14.7 g (73 %, 80 % pure) of the desired molecule were obtained.
~G: 5.09 and 3.17 ppm.

E~amp!e 20 N-Methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 50 ml of DMSO
were treated with carbon dioxide gas for I hours at 25C. 9.81 g of benzyl chloride were then added and after stirring for 45 hours at 25C gas chromato-graphic and mass spectroscopic examination showed the desired product to be present in a yield of 56.2 % of theory (M+ = 241). In addition, N-methyl-N-phenyl-benzylamine had been formed in a yield of 37.0 % of theory. After working up as described in Exarnple 1, 7.8 g (42 /0) of the desired product were isolated. ~H: 5.15 and 3.30 ppm.

Example 21 Propargyl N-methyl-N-phenylcarbamate 8 29 g of N-methylaniline, 18.87 g of potassium carbonate and 50 ml of DMSO
were treated with carbon dioxide gas for 1 hour at 25C. 5.78 g of propargyl chloride were subsequently added and the mixture stirred for a further 45 hours at 25C. After a conversion of 76 %, gas chromatographic and mass spectroscopic Le A 29 700-FC - 25 -'7,1;'' ` ~,, . : : ' . . , , .' ~ 212~07~

examil1ation showed the desired product to be present in a yield of 74.4 % of theory (M+= 189). In addition, N-methyl-N-phenyl-N-propargylamine had been formed in a yield of 20.3 % of theory. After working up as described in Example 16, 7.7 g (52 %, 80 % pure) of the desired product were isolated. IR: 1705 cm~l,~H: 4.71 ppm.

Example 22 Allyl N-methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 50 ml of DMSO
were treated with carbon dioxide gas for 1 hour and 5.93 g of allyl chloride were then added. After 45 hours at 25C gas chromatography and mass spectrometry showed the desired product to be present in a yield of 64.5 % of theory (M~=
191), based on a conversion of 31 %. In addition, N-methyl-N-phenyl-N-allyl-amine had forrned in a yield of 30.3 % of theory.

Example 23 0-[3 -Methoxycarbonyl-2-methoxyprop-2-enyl] N-methyl-N-phenylcarbamate 8.29 g of N-methylaniline, 18.87 g of potassium carbonate and 50 ml of DMSO
were treated with carbon dioxide gas for 1 hour at 25C. 12.79 g of methyl 4-chloro-3-methoxy 2-butenoate were added and the mixture stirred for 45 hours at 25C. The mixture was then examined by gas chromatography and mass spectro-metry. The desired product was present in a yield of 63.4 % of theory (M~ = 279), together with N-methyl-N-phenyl-N-[3-Methoxycarbonyl-2-methoxyprop-2-enyl]-amine. After working up as described in Exarnple 1, 7.1 g (33 %) of the desired product (yH: 5.27, 5.09, 3.67 and 3.31 ppm) with a melting point of 49-50C wereisolated, together with 1.85 g of methyl N-methyl-N-phenyl-4-(3-methoxy)-buten-2-oate.

Le A 29 700-FC - 26 -212~07~

Example 24 Propargyl N,N-dibutylcarbamate 10.0 g of dibutylamine, 18.87 g of potassium carbonate and 250 ml of DMSO
were treated with carbon dioxide gas for I hour at 25C. 5.78 g of propargyl 5 chloride were then added in one portion and the mixture stirred for a further 4 hours. Gas chromatographic analysis showed the desired product to be present in a yield of 99.4 % of theory. In addition, N,N-dibutylpropargylarnine had been formed to the extent of 0.6 % of theory.

Example 2~

10 Propargyl N,N-dibutylacarbamate 200 g of dibutylamine, 378.12 g of` potassium carbonate and 4000 ml of DMSO
were treated with carbon dioxide gas for 150 minutes at 100 mbar superatmosphe-ric pressure (exothermic reaction up to about 35C) and then adrnixed with 115.5 g of propargyl chloride (95 % pure). A~ter 27 hours at 25C the mixture 15 was filtered with suction and distilled. Apart from the fractions which distilled over at temperatures up to 68C at 8 mbar and contained mostly DMSO (together with 57 g of the carbamate), 215 g of the desired product were obtained in a purity of 99 % and with a boiling point of 85-95C at from 0.6 to 0.9 mbar. Thiscorresponds to a total yield of 272 g (88 % of theory).

20 E~ample 26 Allyl N,N-dibutylcarbamate 500 g of dibutylamine, 94.55 g of potassium carbonate and 250 ml of DMSO were treated with carbon dioxide gas for 1 hour and then admixed with 29.95 g of allyl chloride. The mixture was very viscous and was therefore stirred for 30 days.
25 During this time carbon dioxide was continually fed in and a further 14.8 g of allyl chloride was 20 days and again after 23 days. After filtering with suction and dillistation 24.95 g of allyl N,N-dibutylcarbamate were obtained (30.2 % of theory). The product had a boiling point of 69C at 0.1 mbar.

Le A 29 700-FC - 27 -~'~,','' . . ' ~ ' 212507~
Exam~le 27 Propargylsarcosine carbamate 11.9 g of sarcosine ethyl ester hydrochloride, 29.55 g of potassium carbonate and 50 ml of DMSO were treated with carbon dioxide gas for 1 hour and then 5 admixed with 5.78 g of propargyl chloride. After 22 days the mixture was filtered with suction, diluted with methylene chloride, washed with 5 % aqueous hydrochloric acid and the organic phase was concentrated. 6.3 g of a dark oil were obtained, which corresponds to 37 % of theory, and the product was 91 % pure.
M~ = 199, base 126. yH: 4.72 and 4.0 ppm.

10 E~am~le 28 Propargylsarcosine carbamate 8.0 g of sarcosine ethyl ester hydrochloride were treated with 20 % strength aqueous sodium hydroxide solution in diethyl ether at 0C. The organic phase wasdried and concentrated. 12.81 g of potassium carbonate and 50 ml of DMSO were 15 then added. After treatment with carbon dioxide gas for 1 hour, 3.88 g of propargyl chloride were added. After 30 hours at 25C gas chromatographic analysis was conducted, which showed 84.4 % of the desired product to be present.

Example 29 20 4-Chloro-2-butinyl N-(3-chlorophenyl)carbamate 9.89 g of 3-chloroaniline, 18.87 g of potassium carbonate and 50 rnl of DMSO
were treated with carbon dioxide gas for 1 hour at Z5C and 9.54 g of 1,4-dichlorobut-2-ine were then added. After 43 hours the desired product was found in 12 % yield by gas chromatographic and mass spectroscopic analysis. The mass 25 spectrum was identical with that of the known herbicide barban, which is also 4-chloro-2-butinyl N-(3-chlorophenyl)carbamate.

Le A 29 700-FC - 28 -~ 2~25~7~
ExamDle 30 Polymer with units of the formula ~-(CH2~6-O-CO-N~N-CO-O- ) 71 g of piperazine, 450 g of carbon dioxide and 500 ml of DMSO were maintained at 100C for 30 minutes and 200 g of 1,6-dibromohexane were then added at 50C and the mixture was maintained at 70C for 10 hours. After depressurization the mixture was concentrated on a rotary evaporator and subsequently extracted with 3 l of methylene chloride. The organic phase was -again concentrated to give a water-soluble polymer with the following parameters: `

M,,,, = 1057 g/mol, u = 0.68 Mn= 630 g/mol Mz = 1920 g/mol, uz = 0.82.
The parameters were determined by GPC.

Example 31 15 Polymer with units of the formula (CH2~CH2 CO--N~N-CO-O) 49.1 g of piperazine, 423 g of potassium carbonate, 1250 ml of DMSO and 200 g of carbon dioxide were heated to 100C for 30 minutes in a stainless steel autoclave and 100 g of a,a-dichloro-p-xylene were then added. After 6 hours at 50C and a further 6 hours at 80C, working up as in l~xample 30 gave a polymer whose parameters were determined as described in Example 30. .
Mw= 24a,3 g/mol, u = 1.49 Mn= 982 g/mol Mz= 4727 g/mol, uz = 0.93.

Le A 29 700-FC - 29 -,,;~:...... .

21 2507~
, ~
Example 32 0-4-(3-Methoxycarbonyl-2-methoxyprop-2-enyl) N-3-pyridylcarbamate 7.29 g of 3-aminopyridine, 18.87 g of potassium carbonate and 50 ml of DMSO
were treated with carbon dioxide gas for I hour and then admixed with 15.55 g ofmethyl 4-chloro-3-methoxy-2-butenoate. After 116 hours at 25C, analysis by gas chromatography and mass spectroscopy showed 43 % of theory of the desired product. M~ = 266, base: 121).

Ex~mple 33 Compound identical with that of Example 2/2 in WO 93/7116 1.54 g of 3-trifluoromethyl-N-methylaniline, 150 ml of DMSO and 4.87 g of potassium carbonate were treated with carbon dioxide gas ~or 2 hours at 1.1 bar and 2.5 g of methyl 2-(2-bromomethylphenyl)-3-methoxyacrylate was then added and the mixture was stirred for 6 days at 25C. After working up as in Example 1, 2.2 g (59 % of theory, 86 % pure) of the desired molecule were obtained. The IH-NMR spectrum of the compound prepared was identical with that known from WO 93M116.

ExamDle 34 D-glucopyranosyl-(dibenzylcarbamate)-tetraacetate :

A mixture of 4.80 g (0.0243 mol) dibenzyl amine, 40 ml of dimethylsulfoxide and 6.72 g (0.0486 mol) of potassium carbonate was stirred for one hour at 25C .:
during which a constant stream of carbon dioxide was passed through the apparatus. Then 10.0 g (0.0243 mol) cc-D-glucopyranosylbromide-tetraacetate (97 % pure) was added and the mixture was stirred for additional 28 hours followed by filtration and evaporation of the solvent. The remaining oil was chromatographated using KG 60 silicon gel and toluene as a solvent. The main fraction crystallized after removing the solvent, yield 5.87 g, m.p. 115-116C. In the 13C-NMR four signals due to acetate ~170.6, 170.1, 169.4, 169.2 ppm) and onedue to carbamate (1543 ppm) were observed.

Le A 29 700-FC - 30 -212~07~
Exampie 3~

Propan-2-on N,N-dibutylcarbamate 10.0 g of dibutylamine, 21.39 g of potassium/carbonate and 200 ml of DMSO
were admixed with 7.17 g of chloroacetone after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 24 hours at 25C the formation of the desired product in a yield of 89 % was determined by gas chromatography. The mass spectrum showed M~ = 229.

Example 36 3-Aza-3-ethyl-pentan-2-on N,N-dibutylcarbamate 10.0 g of dibutylamine, 21.39 g of potassium carbonate and 200 ml of DMSO
were admixed with 11.59 g of N-(2-chloroacetyl)-diethylamine after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 24 hours at 25C the formation of the desired product in a yield of 99 % W?~S
determined by gas chromatography. The mass spectrum showed M~ -- 286.

Ex:lmple 37 1-(Ethoxycarbonyl~propan-2-on N,N-dibutylcarbamate 10.0 g of dibutylamine, 21.39 g of potassium carbonate and 200 ml of DMSO
were admixed with 12.75 g of ethyl 2-chloroacetoacetate after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 30 hours at 25C the formation of the desired product in a yield of 46 % was determined by gas chromatography. The mass spectrum showed ~ = 301.

Le A 29 700-FC - 31 -~".. . . . ..

~,;,.; . , }; ,,: , . .
;,:,,.,.. - :

y~

~ 212~07~
Example 38 1-(Dimethylaminocarbonyl)propan-2-on N,N-dibutylcarbamate 10.0 g of dibutylamine, 21.39 g of potassium carbonate and 200 ml of DMSO
were admixed with 12.67 g of dimethyl 2-chloroacetoamide after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 24 hours at 25C the formation of the desired product in a yield of 71 % was determined by gas chromatography. The mass spectrum showed M~ = 300.

~2 1-Acetylpropan-2-on N,N-dibutylcarbamate 10.0 g of dibutylamine, 21.39 g of potassium carbonate and 200 ml of DMSO
were admixed with 10.35 g of 3-chloro acetylacetone after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 24 hours at25C the formation of the desired product in a yield of 47 % was determined by gas chromatography. The mass spectrum showed ~ = 271.

E~amPle 40 Propargyl N-methyl-N-benzyl carbamate ~ .:

88.0 g of N-methyl-N-benzylamine, 200.73 g of potassium carbonate and 750 ml of DMSO were admixed with 54.18 g propargyl chloride after treatment wilh carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure.

20 After 48 hours at 25C the mixture was filtered and distilled. At a boiling point of 123C at 0.9 mbar 90.0 g of the desired product were obtained in a purity of 97 %.

Le A 29 700-FC - 32 -~ 212~0 74 Example 41 ((Ph-CH2)2-N-c(0)-0)2-~H2 50.0 g of Dibenzylamine, 175.4 g of potassium carbonate and 500 ml of D~ISO
were admixed with 88.2 g of methylene-bromide after treatment with carbon dioxide gas for I hour at 70~C in an autoclave at about 30 bar pressure. After 16 hours at 70C the mixture was filtered and the solvent was evaporated. The remaining solid was washed with hexane and dried. Melting point 86-89C, yield:
86.7 g (64.4 % of theory).

Example 42 , Example 41 was repeated but using instead of methylene bromide methylene chloride (86.3 g) and 1.66 g of potassium iodide. Yield: 65.6 g, 52 % of theory.
Example 43 Benzyloxycarbonyl-nipecotinic acid ethylester 25 g of ethyl nipecotinic acid ester, 43.95 g of potassium carbonate and 200 ml of DMSO were admixed with 20.4 g of benzyl chloride af~er treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After 9 days at 25C the mixture was washed with 5 % by weight strength aqueous hydrogen chloride and ethyl acetate and dried with sodium sulfate. After removing the solvent in vacuo the remaining oil was found to be the pure desired product.
Yield: 25.0 g, IH-NMR data: 7.35 ppm, 5.13 ppm (only important signals given).

Example 44 (1 -Naphthylmethyl)-N,N-dimethylcarbamate 10 0 g of a reaction product of 2 mol dimethylamine and 1 mol CO2 (sold as "Dimcarb" by Fa. Schuchardt, Germany), 41.19 g of K2CO3 and 200 ml DMSO
were admixed with 26.30 g (1-chlormethyl)-naphthalene after treatment with carbon dioxide gas for 2 hours at 100 mbar superatmospheric pressure. After Le A 29 700-FC - 33 -,~,.: , " : . ~

~ ~2~07~
65 hours at 25C the mixture was worked up as described in Example 1, 12.13 g (71 % of theory) of the desired product were obtained. lH-NMR-data: 5.57, 2.93 and 2.86 ppm.

Example 45 [~ ~f CH3~CO2CH3 A solution of 40 g of sodium hydride (60 % strength) in 1000 rnl dimethyl-formamide was brought together with 100 g of methyl-2-(2-methyl-4-chloro-phenyl)-acetic acid methylester (see U.S. patent 4,424,394) at 20C in the course of 20 minutes. After stirring for 2 hours at 2C, there were added dropwise 189 g 10 dimethylsulfate and the mixture was left standing over night. Thereafter, themixture was extracted with methylene chloride, the mixture of ice and water was added, the organic phase was separated, dried with sodium sulfate and distilled.The boiling point was 121 to 135C at 0.25 mmHg pressure. In this manner, there were obtained 104.9 g methyl-2-(2-methyl-4-chlorophenyl)-3-methoxyacrylate.

lS 27.37 g of this product, 350 ml tetrachloromethane and 22.45 g N-bromosuccin-imide were heated to reflux for 90 minutes after having added 0.5 g of dibenzoyl-peroxide. After filtration and evaporation of the solvent there were obtained 24 g of methyl-2-(2-bromomethyl-4-chlorophenyl)-3-methoxyacrylate with a melting point of 48C.

This compound (8.6 g) was reacted as described in Example 33 for another acrylicacid methylester thereby using 27.08 g of potassium carbonate and 8.6 g of 3-trifluoromethyl-N-methylaniline. The working up of the reaction mixture was carried out as described in Example 33. The desired product was obtained in thismanner in a yield of 11.01 g. The IH-NMR-spectlum showed following signals:

7.56 ppm, s(2H), 7.47 ppm, s(2H), 7.25 ppm, dd(2H), 7.06 ppm, d(lH), 5.05 ppm, s(2H), 3.79 ppm, s(3H), 3.67 ppm, s(3H) and 3.34 ppm, s(2H).

Le A 29 700-FC - 34 -

Claims (12)

1. A process for preparing organic carbamates from a basic amine, carbon dioxide and an alkylating agent, in which the amine is first reacted with carbondioxide in the presence of at least one basic compound of the elements lithium, sodium, magnesium, potassium, calcium, rubidium, strontium, caesium, barium and or ammonium and the alkylating agent then added.

2. The process of claim 1, in which the basic amine used is of the formula (I) (I), in which R1, R2, R3 and R4 are the same or different and are each hydrogen or one of the following radicals in monovalent form: C1-C30-alkyl, C3-C30-alkenyl, C3-C30-alkinyl, C3-C12-cycloalkyl, C5-C12-cycloalkenyl, C8-C12-cycloalkinyl, C6-C14-aryl, C5-C13-hetaryl having up 3 oxygen, sulphur and/or nitrogen atoms in the ring system, C7-C20-aralkyl, C9-C20-aralkenyl, C9-C20-aralkinyl, C7-C20-alkaryl, C8-C20-alkenearyl or C8-C20-alkinearyl, which are unsubstituted or substituted from one to five times by O-C1-C12-alkyl or -C6-C10-aryl, NH2, NH-C1-C12-alkyl or -C6-C10-aryl, N(C1-C12-alkyl or -C6-C10-aryl)2, COO-C1-C12-alkyl or COO-C6-C10-aryl, CONH2, CONH-C1-C12-alkyl, CON(C1-C12-alkyl)2, halogen, OP(O-C1-C12-alkyl or -C6-C10-aryl)2, Si(C1-C12-alkyl and/or C6-C10-aryl)3, Si(O-C1-C12-alkyl and/or C6-C10-aryl)3, Si(C1-C12-alkyl or -C6-C10-aryl)(O-C1-C12-alkyl and/or O-C6-C10-aryl)2, Si(C1-C12-alkyl and/or C6-C10-aryl)2(O-C1-C12-alkyl or O-C6-C10-aryl), OS(C1-C12-alkyl or C6-C10-aryl),O2S(C1-C12-alkyl or C6-C10-aryl), CHO, CN, C(O-C1-C12-alkyl or -C6-C10-aryl)2, OC(C1-C12-alkyl or C6-C10-aryl), NO2, CF3, OCF2H, OCFH2, OCF2CF3, OCH2CF3, OCO(C1-C12-alkyl or C6-C10-aryl), HNCO(C1-C12-alkyl or C6-C10-aryl), OP(C1-C12-alkyl or C6-C10-aryl)3, OP(O-C1-C10-alkyl or -C6-C10-aryl)2 (C1-C12-alkyl or C6-C10-aryl) and/or can optionally be interrupted by oxygen or sulphur atoms or by N(C1-C12-alkyl or C6-C10-aryl) groups, where R1 and R2 or R3 and R4 can, in each case together, also be one of the above-defined radicals, albeit then in divalent form, or R3 and R4 can together be a from 3- to 10-membered alkyl ring, which can optionally be substituted with one or two C1-C10-alkyl groups and/or optionally be interrupted by one or two oxygen, sulphur and/or nitrogen atoms, A is hydrogen or a radical as defined for R1, although in divalent form, m is zero or an integer from 10 to 10 and n is an integer from 1 to 10, with the provisos that a) R1, R2, R3 and R4 are not radicals which contain an isolated .alpha.,.beta. multiple bond, b) in the case of m ? zero, at least one of the radicals R1, R2, R3 and R4 is hydrogen, c) in the case of A = hydrogen, m is zero and d) in the case of A = hydrogen, R1 and R2 are not also simultaneously hydrogen.

3. The process of claim 2, in which the basic amine used is of the formula (I) in which R1, R2, R3 and R4 are the same or different and are each hydrogen or one of the following radicals in monovalent form:

C1-C14-alkyl, C3-C10-alkenyl, C3-C10-alkinyl, C3-C12-cycloalkyl, C5-C7-cycloalkenyl, C6-C10-aryl, C5-C10-hetaryl having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system C7-C12-aralkyl or C7-C10-alkaryl, which an unsubstituted or substituted one to five times by O-C1-C6-alkyl or C6-C10-aryl, NH2, NH-C1-C6-alkyl or -C6-C10-aryl, N(C1-C6-alkyl or -C6-C10-aryl)2, COO-C1-C6-alkyl, COO-C6-C10-aryl, CONH-C1-C6-alkyl, CON(C1-C6-alkyl)2, OS(C1-C6-alkyl or phenyl), O2S(C1-C6-alkyl or phenyl), CHO, CN, OC(C1-C6-alkyl or phenyl), NO2, CF3, OCF3, OCF2H, OCFH2, OCO-(C1-C6-alkyl or phenyl) or HNCO(C1-C6-alkyl or phenyl), and/or can optionally be interrupted by oxygen or sulphur atoms or by N(C1-C6-alkyl or phenyl) groups, where R1 and R2 or R3 and R4 can, in each case together, also be one of the above-defined radicals, albeit then in divalent form, or R3 and R4 can together be a from 5- to 7-membered alkyl ring, which can optionally be substituted with one or two C1-C6-alkyl groups and/or optionally be interrupted by an oxygen or sulphur atom or an N(C1-C6-alkyl or phenyl) group, A is hydrogen or a radical defined as preferred for R1, in divalent form, m is zero or an integer from 1 to 5 and n is an integer from 1 to 5, with the provisos that a') R1, R2, R3 and R4 are not radicals which contain an isolated .alpha.,.beta. multiple bond, b') in the case of m ? zero, at least one of the radicals R1, R2 R3 and R4 is hydrogen, c') in the case of A = hydrogen, m is zero and d') in the case of A = hydrogen, R1 and R2 are not simultaneously hydrogen.

4. The process of claim 1, in which the carbon dioxide used is the usual commercial product, dry ice or isotopically enriched carbon dioxide.

5. The process of claim 1, in which the alkylating agent used is of the formula (II) (II), in which R5, R6 and R7 are the same or different and are each one of the following radicals in divalent form: C1-C30-alkyl, C4-C12-cycloalkyl, C3-C30-alkenyl, C5-C12-cyclo-alkenyl, C3-C30-alkinyl, C8-C12-cycloalkinyl, C7-C20-aralkyl, C8-C20-aralkenyl, C8-C20-aralkinyl, C8-C20-alkenaryl, C8-C20-alkinaryl, C5-C13-alkenehetaryl or C5-C13-alkinehetaryl, the latter two each having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system, where chains in the molecules can be linear, branched and/or optionally interrupted by oxygen, sulphur, N(C1-C12- or C6-C10-aryl), CO, COO, SO, SO2 or SO(O)O or OP(C1-C12-alkyl or C6-C10-aryl) groups, where the groups R6-Y and :R7-Z can also be hydrogen and in this case R5 can optionally be additionally substituted by COO(C1-C12-alkyl or C6-C10-aryl), O-C(O)-(C1-C12-alkyl or C6-C10-aryl), CON(C1-C12-alkyl or C6-C10-aryl)2, (CH2-O-C(O)-C1-C12 alkyl or C6-C10 aryl), C6-C10-aryl, C5-C11-hetaryl having up to 3 oxygen, sulphur and/or nitrogen atoms in the ring system, O(C1-C12-alkyl orC6-C10-aryl), N(C1-C12-alkyl or C6-C10-aryl)2, OP(OC-C1-C12-alkyl or C6-C10-aryl)2, Si(O-C1-C12-alkyl or -C6-C10-aryl)3, Si(C1-C12-alkyl or C6-C10-aryl)3 orhalogen, o and p independently of one another are each zero or 1, B is not present if o = p = zero, in the case of p= 1 and o = zero, B is one of the following radicals in divalentform: CH2, N(C1-C12-alkyl or C6-C10-aryl), OP(C1-C12-alkyl or C6-C10-aryl), phenyl, naphthyl, (CH2)q with q = 2 to 30 or (CH2)r-M-(CH2)s with r and s being the same or different and each = 1 to 20 and M = an oxygen or sulphur atom or an SO2 or N(C1-C12-alkyl or C6-C10-aryl) group, in the case of p = 1 and o = 1, B is one of the following radicals in trivalent form: CH, N, (O)P, phenyl or naphthyl and X, Y and Z independently of one another are each a leaving group.

6. The process of claim 1, in which the alkylating agent is of the formula (III) X - R5' (III), in which R5 is one of the following radicals in monovalent form: C1-C20-alkyl, C4-C12-cyc-loalkyl, C3-C30-alkinyl, C7-C20-aralkyl, C8-C20-aralkenyl, C8-C20-alkenaryl, C8-C20-alkinaryl, C5-C13-alkenehetaryl or C5-C13-alkinehetaryl, the latter two each having up to 2 oxygen, sulphur and/or nitrogen atoms in the ring system and X isa leaving group.

7. The process of claim 1, in which from 0.01 to 10,000 equivalents of carbon dioxide and from 0.01 to 10,000 equivalents of alkylating agent are used per equivalent of amine used.

8. The process of claim 1, in which the basic compound of the elements lithium, sodium, magnesium, potassium, calcium, rubidium, caesium, barium and/or of ammonium used is an alkali or metal carbonate and/or metal hydrogen carbonate.

9. The process of claim 1, in which the basic compound is potassium carbonate.

10. The process of claim 1, which is carried out inh the presence of at least one solvent selected from hydrocarbons, ethers, amines, esters, nitro-compounds, nitriles, tetrahydrothiophene dioxide, dimethyl sulphoxide, tetramethylene sulphoxide, propyl sulphoxide, benzylmethyl, sulphoxide, diisobutyl sulphoxide, ketones, liquefied carbon dioxide, polyethers of ethylene and/or propylene oxideand amides.

11. The process of claim 1, which is carried out in the presence of dimethyl-formamide or dimethyl sulphoxide or mixtures of these with other solvents mentioned in claim 10.

12. The process of claim 1, which is carried out at from -50 to +180°C.