WO1993014065A1

WO1993014065A1 - Process for preparing 1,3,5- tris(4'-hydroxyphenyl)benzene and its derivatives

Info

Publication number: WO1993014065A1
Application number: PCT/US1992/011015
Authority: WO
Inventors: Mohammad Aslam; Daniel Alfonso Aguilar
Original assignee: Hoechst Celanese Corp
Current assignee: CNA Holdings LLC
Priority date: 1992-01-08
Filing date: 1992-12-18
Publication date: 1993-07-22
Anticipated expiration: 1994-07-08

Abstract

Compounds of formula (I) wherein R1 is hydrogen, alkyl, halogen, nitro or alkyl or aromatic sulfonyl, x is an integer from 1 to 4, when x is greater than 1, The R1 substituents on any one or all of positions 2, 3, 5 and 6 and can be the same or different, and R is (III, IV or V), wherein each of R?2 and R3¿ is an alkyl group, a substituted alkyl group, an aromatic or a substituted aromatic, and R?2 and R3¿ can be the same or different. Intermediates and methods of making such novel compounds, as well as using them and 4-hydroxyacetophenone derivatives to make 1,3,5-tris(4' -hydroxyphenyl)benzene compounds are also disclosed and claimed.

Description

PROCESS FOR THE PREPARATION OF 1,3,5-TRTS(4'-HYDROXY- PHENYL) BENZENE AND ITS DERIVATIVES

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is also made to the commonly owned and concurrently filed U.S. patent applications of Aslam et al., Serial No. 07/819,168 filed January 8, 1992, and of Hilton Serial No. 07/819,166, filed January 8, 1992, incorporated herein by reference.

This application also discloses and claims subject matter disclosed in copending U. S. Patent Application Serial No.: 07/819,167 filed January 8, 1992 and is a continuation application thereof.

FIELD OF THE INVENTION

This invention relates to derivatives of 1,3,5-tris (4'- hydroxyaryl) benzene, intermediate compounds and methods for making these compounds More specifically, the invention relates to novel 1,3,5-tris (4'-acyloxy-substitutedphenyl) benzenes, 1,3,5- tris [4'-0-(N,N'-disubstitutedthiocarbamoyl) -phenyl] benzenes and 1,3,5-tris (4'-substitutedsulfonoxyphenyl) benzenes and methods for making these compounds. In one process, the corresponding acetophenones, namely the 4- acyloxyacetophenones , the novel 4' - substitutedsulfonyloxyacetophenones and the 0-(4'- acetylphenyl)-N,N'-disubst itutedthiocarbamates, are trimerized under appropriate reaction conditions. The electron withdrawing groups, that is,

of the resulting trimers may be hydrolyzed to form 1,3,5- tris (4'-hydroxyaryl) benzenes. The invention also includes trimerizing 4-hydroxyacetophenone, a 4-hydroxyacetophenone derivative, or a 4-substitutedoxyacetophenone by contacting such a compound with a tetrahalosilane, for instance tetrachlorosilane, preferably in an alkyl alcohol, for example, a lower alkyl alcohol such as methanol, ethanol, propanol or the like. BACKGROUND OF THE INVENTION

1,3,5-tris (4'-hydroxyphenyl) benzene (THPB) falls into the class of compounds known as trisphenyls. Trisphenyls have been recognized as useful intermediates in the preparation of more complex organic structures. For example, reacting trisphenyls with formaldehyde, acid anhydrides and more importantly with epichlorohydrin produces epoxide resins. Epoxide resins prepared from such compounds exhibit low shrinkage, extraordinary hardness, chemical inertness, outstanding mechanical strength, and a variety of beneficial features. See, for example, U.S. Patent No. 4,394,496; and, the commonly owned, concurrently filed application of Hilton, Serial No. 07/819,166, filed January 8, 1992, incorporated herein by reference. 1,3,5-tris (4'-hydroxyaryl) benzene (THAB) molecules are particularly useful in their ability to stabilize polycarbonates. This is accomplished via a three site rigid D_3h crosslink. THAB molecules may also be used as crosslinking agents in epoxy resins. See, for example, Chem. Abstracts, 66, 3004C. Thus, the compositions obtained by the invention are useful for their epoxidation products which can be used to form epoxy resins and also can be used in the preparation of polycarbonates. THPB was first reported in Beilstein, E II 6 , 1115

(1921), as the result of the treatment of 4- methoxyacetophenone (4-MAP) with sulfuric acid to obtain a

20% yield of 1,3,5-tris (4'-methoxyphenyl) benzene (4-MAP trimer or TMPB). This compound was demethylated with concentrated hydrochloric acid to yield THPB.

THPB was also reported in Chimia, 12, 143 (1958) as formed by the trimerization of 4-haloacetophenone, where the halogen is either bromine or chlorine, in the presence of potassium pyrosulfate and sulfuric acid. This reaction results in 1,3,5-tris (4'-halophenyl) benzenes. These halogen-containing trimers were treated with sodium hydroxide and converted to THPB.

M.H. Karger and Y. Mazur, J. Org. Chem, 36, 540 (1971), reported that anisole and acetyl methanesulfonate, affords 4-MAP (46% yield) and TMPB (41% yield). Subsequent to anisole acetylation, trimerization is effected and is apparently catalyzed by methanesulfonic acid. R.E. Lyle, E.J. DeWitt, N.M. Nichols, and W. Cleland, J. Amer. Chem. Soc., 75, 5959 (1953), report the trimerization of substituted acetophenones, i.e., 4-MAP to TMPB (54% yield), by a alcoholic hydrochloric acid solution, after four months at room temperature.

G.P. Sharin, I.E. Moisak, and E.E. Gryazin, Zhurnal Prikladnoi Khimii, 43, 1642 (1970), report the trimerization of 4-MAP to TMPB (27% yield) using a mixture of potassium pyrosulfate and sulfuric acid. This article also relates an unsuccessful attempt to trimerize 3-HAP. See also, A.F. Odel et al., J. Amer. Chem. Soc. 36, 81 (1913).

Starnes et al. U.S. Patent No. 3,458,473, issued July 29, 1969 and Starnes et al. U.S. Patent No. 3,644,538, issued February 22, 1972 are directed to the preparation of various hindered trisphenols. The hindered trisphenols of both Starnes references are prepared by the cyclotrimerization of an acetylphenol which is the precursor. The acetylphenol precursors are combined with triethylorthoformate in a solvent and then treated with gaseous hydrogen chloride.

U.S. Patent No. 3,026,264 to Rocklin et al., issued March 20, 1962 is directed to polynuclear polyphenols and stabilized compositions containing such compounds. The substituted benzenes of Rocklin are prepared by alkylation of a trialkylbenzene with 3,5-dialkyl-4-hydroxy-benzyl alcohol under alkylating conditions and in the presence of sulfuric acid or a Friedel-Crafts catalyst. U.S. Patent No. 3,053,803 to Jaffe et al., issued September 11, 1962 concerns polynuclear phenols, including tri (hydroxybenzyl) benzenes. The polynuclear phenols of Jaffe are taught to be useful as phenolic anti-oxidants for stabilized compositions. The polynuclear phenols of Jaffe are prepared by reacting a mononuclear aryl compound having up to two hydroxyl substituents attached to ring carbon atoms and having at least two replaceable hydrogen atoms attached to ring carbon atoms, with 3,5-dialkyl-4- hydroxybenzyl alcohol, in an inert solvent containing a catalytic amount of a catalyst selected from the group consisting of sulfuric acid and Friedel-Crafts catalysts.

German Patent 258,929 to Zimmerman et al., issued August 10, 1988 is directed to methods for the production of 1,3,5-tris (triarylbenzene) compounds. These compounds are reacted by combining 2,4,6-triaryl pyrylium salts with carboxylic acid anhydride in the presence of a basic condensing agent. The reaction of Zimmerman utilizes triaryl pyrylium carboxylic anhydride.

Elmorsy et al., "The Direct Production of Tri- and Hexa-Substituted Benzenes from Ketones Under Mild Conditions," Tetrahedron Letters, Vol. 32, No. 33, pp. 4175- 4176 (1991) report the treatment of aryl benzenes with tetrachlorosilane in ethanol to yield 1,3,5-triarylbenzenes. However, Elmorsy et al. fail to teach or suggest trimerizing 4-hydroxyacetophenone, a 4-hydroxyacetophenone derivative, or a 4-substitutedoxyacetophenone by contacting such a compound with a halosilane, as in the present invention. Indeed, it is believed that trimerizing a hydroxyacetophenone such as 4-hydroxyacetophenone or a 4- hydroxyacetophenone derivative, is not disclosed or suggested by Elmorsy et al. because of the belief that the hydroxy group would interfere with the reaction, for example, react with the tetrachlorosilane. See, e.g., Sharin et al., supra, which illustrate why it was believed, before now, that direct trimerization of hydroxyacetophenone was not feasible. Accordingly, Elmorsy et al. fail to teach or suggest the present invention.

THE SUMMARY OF THE INVENTION

This invention relates to derivatives of 1,3,5-tris (4'- hydroxyphenyl) benzene, various intermediate compounds and methods for making these compounds.

The 1,3,5-tris (4'-hydroxyphenyl) benzene derivatives of the invention have the general formula I:

and are prepared by trimerizing compounds of the formula:

In each of these formula, R is an electron withdrawing group such as

in which each of R² and R³ is a C₁-C₂₀ alkyl, e.g., C₁-C₅ lower alkyl such as methyl or ethyl, a substituted alkyl, e.g., alkyl substituted by one or more halogen and/or nitro, or an aromatic such as phenyl, or an aromatic substituted by an alkyl and/or halogen and/or nitro such as tolyl, cumenyl, xylyl, mesityl, or an aryl halide, for instance a halophenyl such as chlorophenyl, R² and R³ being the same or different; R¹ is hydrogen, an alkyl group such as an alkyl group having from 1 to about 12 carbon atoms, preferably a C₁-C₅ lower alkyl, e.g., methyl or ethyl, a cycloalkyl of from about 3 to about 6 carbon atoms, phenyl, halogen, e.g., Cl, F, Br or I, nitro, or an alkyl sulfonyl or aromatic sulfonyl in which the alkyl group preferably has 1 to about 12 carbon atoms, more preferably the alkyl group is a C₁-C₅ lower alkyl group or a substituted alkyl, e.g., a C₁-C₅ lower alkyl substituted by one or more halogen and/or nitro groups; and, the aromatic is phenyl or a substituted aromatic such as an alkyl substituted aromatic, e.g., tolyl, cumenyl, xylyl, mesityl, an aromatic substituted by one or more halogen and/or nitro groups, e.g., a halo-substituted aromatic or a nitro-substituted aromatic; x is an integer of from 1 to 4; and when x is greater than 1, the R¹ substituents can be the same or different.

The general reaction scheme of the present invention is :

4-HAP

Derivative 4-HAP sub

1,3,5-tris(4-Substituted THPB derivative phenyl)benzene derivative

wherein R, R¹ and x are defined as above.

The reaction involves the use of 4-hydroxyacetophenone derivatives (4-HAP derivative) to prepare 4- substitutedoxyacetophenones (4-HAP subs) such as 4- acyloxyacetophenones, 4-substitutedsulfonyloxyacetophenones and 0-(4'-acetylphenyl)-N,N'-disubstitutedthiocarbamates. The 4-HAP sub compounds prepared in the present invention have the general formula II:

wherein R is an electron withdrawing group such as

The trimerization of the compounds of formula II results in the new 1,3,5-tris (4'-hydroxyphenyl) benzene derivatives such as 1,3,5-tris (4'-acetoxyphenyl) benzene, 1,3,5-tris (4'-methanesulfonoxyphenyl) benzene and 1,3,5- tris [4'-0-(N,N'-dimethylthiocarbamoyl)phenyhl]benzene. These derivatives are not only useful for preparing THPB, but also, like THPB, they can be used to form more complex organic structures. Furthermore, they can be used in the preparation of polycarbonates.

The hydrolysis of the electron withdrawing protecting group, III, IV, and V, e.g., the acetoxy, the mesylate or the N,N'-dimethylthiocarbamoyl of the compounds of formula

I results in a 1,3,5-tris(4'-hydroxyphenyl)benzene derivative.

Thus, for example, in an embodiment of the inventive process, a compound such as 4-acetoxyacetophenone or a derivative is trimerized with dimethoxyethane and triethyl orthoformate to form a new compound, 1,3,5-tris (4'- acetoxyphenyl) benzene or one of its derivatives. The 1,3,5- tris (4'-acetoxyphenyl) benzene derivative is in turn hydrolyzed to a 1,3,5-tris (4'-hydroxyphenyl) benzene. Another embodiment provides for the preparation of compounds such as 1 , 3 , 5 - t ris ( 4 ' - methanesulfonoxyphenyl) benzene and 1,3,5-tris (4'- hydroxyphenyl) benzene and their derivatives by trimerizing 4-methanesulfonyloxyacetophenone (4-HAP mesylate) or a derivative of the formula

in a water scavenger such as methanesulfonyl chloride arid methanesulfonic acid catalyst to produce 1,3,5-tris (4'- methanesulfonoxyphenyl) benzene (or the corresponding derivative). This new compound in turn is cleaved by hydrolysis to form 1,3,5-tris (4'-hydroxyphenyl) benzene or a derivative thereof.

The 4-HAP mesylate and its derivatives, are formed by mesylating the corresponding 4-hydroxyacetophenone (4-HAP), for example, by contacting the 4-HAP compound with methanesulfonyl chloride.

Alternatively, an embodiment of the present invention includes a process for the preparation of a 1,3,5-tris (4'- hydroxyphenyl) benzene derivative, which comprises contacting a compound such as 0-(4'-acetylphenyl) -N,N'- dimethylthiocarbamate or one of its derivatives, with triethyl orthoformate and chloroform under reaction conditions which results in a new compound 1,3,5-tris [4'-0- (N,N-dimethylthiocarbamoyl)-phenyhl]benzene or a derivative which may in turn be hydrolyzed to produce 1,3,5-tris (4'- hydroxyphenyl) benzene or one of its corresponding derivatives.

In a further alternative process, a 4-HAP sub compound of formula II, or a 4-HAP derivative such as 4- hydroxyacetophenone, is contacted with a halosilane, preferably a tetrahalosilane such as tetrachlorosilane, tetrabromosilane, tetrafluorosilane, tetraiodosilane, and the like, to yield the corresponding trimer. The halosilane is preferably present in at least an equimolar amount with respect to the a'cetophenone; and, the contacting is preferably performed in the presence of a solvent such as an alkyl alcohol, for instance, methanol, ethanol, propanol, or the like, more preferably an anhydrous solvent. For example, tetrachlorosilane, dry anhydrous ethanol, and reaction conditions of about 15° to about 80°C, typically about room temperature (e.g., about 20° to about 25°C) and stirring for about 2 to about 100, typically about 4 to about 72, e.g., about 6 to about 48 hours, are preferred. When a 4-HAP sub is so trimerized, the resulting trimer may in turn be hydrolyzed to produce 1,3,5-tris (4'- hydroxyphenyl)) benzene or one of its derivatives.

DETAILED DESCRIPTION

The preparation of 1,3,5-tris (4'-hydroxyphenyl) benzene and its derivatives and precursors is based on the following reactions.

Initially, the 4-HAP derivative may be converted to a 4-HAP sub:

4-HAP

derivative 4-HAP substituted or

"4-HAP sub"

wherein R¹ is hydrogen, an alkyl group (including mono- or poly-substituted alkyl, e.g., with halogen and/or nitro) such as an alkyl group having from 1 to about 12 carbon atoms, preferably a C₁-C₅ lower alkyl, such as methyl or ethyl, a cycloalkyl of from about 3 to about 6 carbon atoms, phenyl (including mono- or poly- substituted phenyl, e.g., with halogen and/or nitro), halogen, such as Cl, Br, F or I, nitro, alkyl sulfonyl or aromatic sulfonyl in which the alkyl group preferably has 1 to about 12 carbon atoms, more preferably the alkyl group is a C₁-C₅ lower alkyl or a substituted alkyl, e.g., a C₁-C₅ lower alkyl substituted by one or more halogen and/or nitro groups, the aromatic is phenyl, a substituted aromatic such as an alkyl substituted aromatic, e.g., tolyl, cumenyl, xylyl, mesityl, or an aromatic substituted by one or more halogen and/or nitro groups; x is an integer from 1 to 4, and when x is greater than 1, the R¹ substituents can be the same or different; and R^P is a precursor compound, which, under reaction conditions provides the substitution of R for H in the 4-HAP derivative. In accordance with the invention, R^P is a halide or anhydride of any one of formulae VI, VIA, VII, VIIA, or VIII:

or V ;

wherein R² and R³ are the same or different and each is a C₁- ₂₀ alkyl, preferably a C_{1 - 5} alkyl and more preferably methyl or ethyl or a substituted alkyl, for instance, an alkyl substituted by one or more nitro and/or halogen groups, e.g., a halo-substituted alkyl or a nitro substituted alkyl, or an aromatic or a substituted aromatic, e.g., an alkyl substituted aromatic such tolyl, cumenyl, xylyl or mesityl, or a halo-substituted or nitro-substituted aromatic; and X is a halogen, e.g., F, Cl, Br, I, preferably Cl. Thus, the R^P compounds of formulae VIA and VIIA can be symmetrical or mixed anhydrides. When the R^P compounds of formulae VIA and VIIA are symmetrical anhydrides, they can be represented as:

(VIA) , and

(VIIA) .

More specifically, R^P can be a symmetrical anhydride of the formula

(VIA)

which is preferably an alkyl anhydride, such as acetic anhydride or a substituted alkyl anhydride, such as, a halo- substituted alkyl anhydride, for instance, trifluoroacetic anhydride, or trichloroacetic anhydride, or an aromatic anhydride such as benzoic anhydride.

Under these circumstances, R will be

R^p can also be a sulfonyl halide of the formula

which is preferably an alkyl sulfonyl halide, such as ethanesulfonyl chloride or methanesulfonyl chloride (mesyl chloride) or an aromatic sulfonyl halide, such as tosyl chloride. Thus, R will be

Or R^p can be

which is preferably a Ν,Ν'-disubstitutedthiocarbamoylhalide such as a N,N'-alkylalkylthiocarbamoylhalide, for instance, N,N'-dimethylthiocarbamoylchloride, or N,N'- methylethylthiocarbamoylchloride. R² and/or R³ may also be aromatic or substituted aromatic, such as phenyl, tolyl, xylyl, mesityl, an aryl halide, or a nitro-substituted aromatic. Therefore, R will be

Looking at the entire reaction in more detail, the 4- HAP derivative may be converted to a 4-HAP sub wherein R is

which is preferably a 4-acyloxyacetophenone, by contacting the 4-HAP derivative with the corresponding R^p anhydride or R^P halide, e.g., chloride, under suitable reaction conditions such as reflux under an inert atmosphere such as nitrogen for a suitable time such as about 2 to 20, preferably about 4 hours. Thereafter, the acid (formed during the reaction) and any excess anhydride or acid halide, e.g., chloride corresponding to R are removed, for instance, distilled, preferably in vacuo, leaving a product. The product is preferably then purified, to yield the 4-HAP sub in which R is R²CO- . 4-HAP can be converted to 4-HAP sub where R is

which is preferably a 4-substitutedsulfonyloxyacetophenone, by contacting the 4-HAP derivative with the corresponding R^p halide or anhydride of formula VII or VIIA under conditions which do not cause excessive decomposition of reactants and/or products, and, which allow for a sufficient yield of desired product. For instance, the 4-HAP derivative can be added to a solvent, for example, methylene chloride, and cooled to an appropriate temperature, for example, about -10 to 20°C, preferably about 0°-15°C, more preferably about 10°C. A base, such as triethylamine is added and preferably the mixture is maintained at the cool temperature. The base to 4-HAP derivative mole ratio is preferably about 2:1 to 1:2, and more preferably about 1:1. The R^p halide or anhydride of formula VII or VIIA in a solvent, such as methylene chloride, is then added, in a mole ratio relative to the 4-HAP of about 2:1 to about 1:2, preferably about 1:1, at such a rate that the reaction temperature preferably is maintained at the cool temperature. The reaction mixture is then allowed to achieve room temperature and stirred or agitated at ambient temperature for about 1 to 24 hours, preferably about 10 to 16 hours, for example, overnight. An additional quantity of the R^p halide or anhydride of formula VII or VIIA, for instance mesyl or tosyl chloride or anhydride, is added in an amount of, for example about 10 to 20%, preferably about 15 to 17% of the amount initially utilized. The mixture is heated with agitation for about 0.5-2 hours, preferably about 1 hour at about 30°-50°C, preferably about 40°C. The reaction mixture is then concentrated, for example, by vacuum, at about 25-35°C, preferably about 30°C. See also Finley et al., U.S. Patent No. 4,128,490, incorporated herein by reference.

While the trimerization of the resultant 4-HAP sub can be performed in the same pot as the substitution of the 4- HAP derivative, without isolating the intermediate 4-HAP sub, the 4-HAP sub formed can be recovered, if desired. For instance, the solids from the concentrated reaction mixture can be slurried in a sufficient quantity of ice water, filtered, and dried, to result in a solid of the 4-HAP sub in which R is R²SO₂-.

When R is

the 4-HAP sub is preferably an 0-(4'-acetylphenyl)-N,N'- disubstitutedthiocarbamate, the 4-HAP derivative is contacted with the corresponding R^p halide of formula VIII under conditions which will not result in significant deterioration of reactants and/or products. Such conditions include forming a cooled solution of alkali hydroxide in alkyl alcohol, such as, KOH in CH₃OH, adding 4-HAP derivative, and, adding the halide corresponding to R, to form a reaction mixture. The reaction mixture is gradually allowed to warm to room temperature. After stirring at room temperature, water is added and the mixture cooled, thereby causing precipitation of a solid. The solid is the 4-HAP sub with R being R²R³NCS-. The solid can be collected, for example, by filtration, washed, for instance, with water, and dried, for example, in vacuo, to obtain the 4-HAP sub in which R is R²R³NCS . See U.S. Patent No. 4,749,205, which is hereby incorporated herein by reference.

Next, upon obtaining the 4-HAP sub, the trimerization and optional hydrolysis reaction proceed as follows:

1,3 ,5-tris(4 -substituted

phenyl)benzene derivative

Generally, in this reaction, the 4-HAP sub is trimerized in an acidic medium to form the corresponding 1,3,5-tris (4'-substitutedphenyl) benzene derivative, which can be isolated and used in that form or can be converted to the corresponding THPB derivative by hydrolysis. The 4- HAP derivative or 4-HAP sub can also be trimerized in the presence of a halosilane. For instance, when R is

the 4-HAP sub which is preferably a 4-acyloxyacetophenone is exposed to an acid such as anhydrous HCl, in a

suitable medium, under reaction conditions which will not cause excessive decomposition while allowing for

sufficient yield of product. For example, the 4- acyloxyacetophenone is mixed with 1, 2 dimethoxyethane and triethylorthoformate which is cooled, for instance, to about -20° to 20°C, preferably to about 0°C and anhydrous HCl is added until the temperature rises, for example, to about at least 20° to 40°C, preferably at least about 30°C, for about 1 to about 4 hours, typically about 2 hours. The orthoformate to 4-HAP sub mole ratio is preferably about 1:2 to 2:1, typically about 1:1. The remaining HCl is purged, for example, by bubbling an inert gas such as nitrogen into the mixture and the resulting 1,3,5- tris (4'-acyloxysubstitutedphenyl) benzene is recovered. Recovery can include concentrating the reaction mixture, adding an excess of anhydride such as a two to five, preferably a three-fold. molar excess, adding about 0.05 to 0.3, preferably about 0.1 molar equivalents of the salt of the acid corresponding to the anhydride,

refluxing for a suitable time, for example, about 1 to 4 hours, preferably about two hours, and, precipitating the trimer by cooling. The precipitate can then be filtered, washed and dried. Alternatively, the 4-acyloxyacetophenone can be contacted with a suitable acid in liquid form, such as methanesulfonic acid at room temperature to form the 1,3,5-tris-(4'-acyloxysubstitutedphenyl)benzene. The trimer can then be recovered by hydrolysis'.

If desired, the 1,3,5-tris (4'- acyloxysubstitutedphenyl) benzene is conveniently

hydrolyzed to a THPB derivative in a basic alcoholic medium, for example, an alkali hydroxide in alkyl

alcohol, such as NaOH or KOH in methanol or ethanol, at suitable reaction temperature, for example, reflux, for a suitable time, for example, about 4 to 8 hours,

preferably about 6 hours. Since each mole of the trimer contains three moles of

it is preferred that the number of moles of alkali hydroxide be in excess of, preferably a three to 15-fold excess of, the number of moles of trimer. The THPB derivative can be recovered by washing the reaction mixture with an organic solvent such as methylene

chloride and acidifying the aqueous layer to a pH of about 3 to 6.

Alternatively, the acyloxy trimer can be hydrolyzed under acidic conditions. For instance, the acyloxy trimer can be contacted with .an acid catalyst such as HCl, H₂SO₄ and the like, for instance, catalytic amounts of an acid catalyst to an excess of an acid catalyst (with respect to the moles of the trimer); the contacting is preferably in the presence of a solvent such as water or a water miscible organic such as a lower alkyl

alcohol, e.g., methanol, ethanol and the like, and is preferably performed under temperatures and pressures of reflux, and for a time sufficient to effect hydrolysis such as 2 to 12 hours, e.g., 4 to 8 hours.

When R is

the 4-HAP sub, which is preferably a 4- substitutedsulfonyloxyacetophenone, is also trimerized in the presence of an acid and the trimer hydrolyzed.

In this instance, the 4- substitutedsulfonyloxyacetophenone is preferably

contacted with a R²-sulfonyl halide and a corresponding R²-sulfonic acid. For example, 4-HAP mesylate is

preferably contacted with methanesulfonyl chloride and methansulfonic acid, and 4-HAP tosylate is preferably contacted with tosyl chloride and p-toluenesulfonic acid. The mole ratio of the R²-sulfonyl halide to the 4- substitutedsulfonyloxyacetophenone (e.g., methanesulfonyl chloride to 4-HAP mesylate) is about 1:2 to about 2:1, preferably about 1:1; and, the R²-sulfonic acid is present in a mole ratio (to amount of the 4-HAP sub) of about 0.05:1 to about 0.5:1, preferably about 0.1:1 to about 0.44:1. Suitable reaction conditions include times of about 2 to about 100 hours and temperatures of about 25 to about 150°, e.g., 100°C for 40 hr. The resulting

1,3,5-tris (4'-substitutedsulfonoxyphenyl) benzene can then be recovered from the reaction mixture. The trimer can be recrystallized for further purification.

The trimer, if desired, is hydrolyzed to a THPB derivative in a suitable manner such as that described above in the hydrolysis of the 1,3,5-tris (4'- acyloxysubstitutedphenyl) benzene.

In this instance however, the reaction conditions for hydrolysis can include times of, for example, about 1 to 24 hours, preferably about 10 to 16 hours and

temperatures of reflux.

Likewise, when R is

the 4-HAP sub, which is preferably an 0-(4'- acetylphenyl)-N,N'-disubstitutedthiocarbamate, is also conveniently trimerized by contacting it with acid under suitable reaction conditions. For instance, the 0 -(4'- acetylphenyl)-N,N'-disubstitutedthiocarbamate can be dissolved into a solvent such as triethylorthoformate and chloroform, and contacted with anhydrous HCl at about 45 to 65°C, typically about 55°C. The temperature is maintained at about 60° to 80°C, preferably between about 65 and 71°C, for about 1 to about 5, preferably about 2 hours. The orthoformate to 4-HAP sub mole ratio in this instance is typically 1:2 to 2:1, preferably about 3:2. The HCl is purged leaving the 4-HAP sub trimer, 1,3,5- tris [4'-0-(N,N'- disubstitutedthiocarbamoyl) phenyl] benzene which is recovered, for example, by evaporating the chloroform, dissolving the product in ethyl acetate, and washing with water. The resultant organic layer is separated, dried, filtered, concentrated, and the product is recrystallized (e.g., with ethanol). The resulting trimer can be hydrolyzed to the

appropriate THPB derivative in a suitable manner such as that described above in the hydrolysis of the 1,3,5- tris (4'-acyloxysubstitutedphenyl) benzene.

Alternatively, a 4-HAP sub compound of formula II, or a 4-HAP derivative such as 4-hydroxyacetophenone can be trimerized by contacting the acetophenone with a

halosilane. The halosilane is preferably a

tetrahalosilane such as tetrachlorosilane,

terabromosilane, tetrafluorosilane or tetraiodosilane. Tetrachlorosilane is presently preferred. The halosilane is preferably present in at least an equimolar amount with respect to the acetophenone; and, the contacting is preferably performed in the presence of a solvent such as an alkyl alcohol, for instance, methanol, ethanol, propanol, or the like. An anhydrous solvent such as dry ethanol is preferred. The reaction conditions of this alternative embodiment are any conditions which will promote the formation of the product and will not cause significant deterioation of starting materials or

product. Typical conditions include temperatures of about 15°C to about 80°C, more preferably about room temperature (e.g., about 20° to about 25°C) and stirring for about 2 to about 100 hours, usually about 4 to about 72 hours, e.g., about 6 to about 48 hours. For instance, to a stirred solution of the acetophenone in dry ethanol, an equilmolar amount of tetrachlorosilane is added slowly. The mixture is stirred for 72 hours at room temperature. The trimer can then be recovered, for instance, by pouring the reaction mixture into water to afford the trimer. The trimer can be purified, for example, by drying, filtering, concentrating and

recrystallizing. In this alternative the reaction schemes are:

and

wherein R, R¹, and x are as defined above.

It is within the ambit of the skilled artisan from this disclosure to select suitable reagents, solvents, quantities thereof, and suitable reaction conditions, including times and temperatures for the preparation of the 4-HAP sub compounds, for the trimerization of 4-HAP derivatives and of the 4-HAP sub compounds and, for the hydrolysis of such trimers to afford THPB and its

derivatives, especially when factors such as the scale of the reaction are considered.

Examples of 1,3,5-tris (4'-substitutedaryl) benzenes which can be prepared in accordance with the invention include:

1,3,5-tris (4'-acetoxyphenyl) benzene;

1,3,5-tris (4'-trifluoroacetoxyphenyl) benzene; 1,3,5-tris (4'-trichloroacetoxyphenyl) benzene; 1,3,5-tris (2'-alkyl 4'-acetoxyphenyl) benzene; 1,3,5-tris(2',3'-dialkyl, 4'- acetoxyphenyl)benzene;

1,3,5-tris(2'-halophenyl,

4'acetoxyphenyl)benzene;

1,3,5-tris((2',3'-dihalophenyl,

4'acetoxyphenyl)benzene;

1,3,5-tris(2'-alkyl, 4'- trifluoracetoxyphenyl)benzene;

1,3,5-tris(2',3'-dialkyl, 4'- trifluoracetoxyphenyl)benzene;

1,3,5-tris(2'-halophenyl, 4'- trifluoroacetoxyphenyl)benzene;

1,3,5-tris(2',3'-dihalophenyl, trifluoroacetoxyphenyl)benzene;

1,3,5-tris(2'-alkyl, 4'- trichloroacetoxyphenyl)benzene;

1,3,5-tris(2',3'-dialkyl, trichloroacetoxyphenyl)benzene;

1,3,5-tris(2'-halophenyl, 4'- trichloroacetoxyphenyl)benzene;

1,3,5-tris(2',3'-dihalophenyl, trichloroacetoxyphenyl)benzene;

1,3,5-tris[4'-0-(N,N'- dimethylthiocarbamoyl)phenyl]benzene;

1,3,5-tris[4'-0-(N,N'- diethylthiocarbamoyl)phenyl]benzene;

1,3,5-tris[4'-0-(N,-methyl, N¹- ethylthiocarbamoyl)phenyl]benzene;

1,3,5-tris[2'-alkyl, 4'-0-(N,N' dimethylthiocarbamoyl)phenyl]benzene; 1,3,5-tris[2'-halophenyl, 4'-0-(N,N'- dimethylthiocarbamoyl)phenyl]benzene; 1,3,5-tris[2'-alkyl, 3'-halophenyl, 4'-0-(N,N'- dimethylthiocarbamoyl)phenyl]benzene;

1,3,5-tris.(4'-methanesulfonoxyphenyl)benzene;

1,3,5-tris(4'-toluenesulfonoxyphenyl)benzene; 1,3,5-tris(2'-alkyl, 4'- methanesulfonoxyphenyl) benzene;

1,3,5-tris(2'-halophenyl, 4'- methanesulfonoxyphenyl)benzene;

1,3,5-tris(2'-alkyl, 4'- toluenesulfonoxyphenyl) benzene;

1,3,5-tris(2'-halophenyl, 4'- toluenesulfonoxyphenyl)benzene;

1,3,5-tris(2',3'-dialkyl, 4'- methanesulfonoxyphenyl)benzene;

1,3,5-tris(2',3'-dialkyl, 4'- toluenesulfonoxyphenyl)benzene;

1,3,5-tris(2',3'-dihalophenyl, 4'- toluenesulfonoxyphenyl)benzene; and

1,3,5-tris(2',3'-dihalophenyl, 4'- methanesulfonoxyphenyl) benzene;

Examples of 1,3,5-tris(4'-hydroxyaryl)benzenes which can be prepared in accordance with the invention include the products of hydrolyzing the above-listed 1,3,5-tris (4'-substitutedaryl) benzenes as well as:

1,3,5-tris(4'-hydroxyphenyl)benzene;

1,3,5-tris(3'-alkyl,4'-hydroxyphenyl)benzene; 1,3,5-tris(3'-halophenyl, 4'- hydroxyphenyl)benzene;

1,3,5-tris(3'-nitro,4'-hydroxyphenyl)benzene; 1,3,5-tris(2'-alkyl,4'-hydroxyphenyl)benzene;

1,3,5-tris(2'-alkyl,3'-alkyl 4'- hydroxyphenyl)benzene;

1,3,5-tris(2'-nitro,3'nitro,4'- hydroxyphenyl)benzene;

1,3,5-tris(2'-halophenyl,3'halophenyl,4'- hydroxyphenyl)benzene and combinations thereof, e.g.

1,3,5-tris(2'-alkyl,6'-halo,4'-hydroxyphenyl)benzene.

Examples of 4-substituted acetophenones used in the reactions include the acetophenone precursors of the above-listed 1,3,5-tris(4'-substitutedaryl)benzenes, such as:

0-(4'-acetylphenyl)-N,N'-dimethylthiocarbamate; 0-(4'-acetylphenyl)-N,N'-diethylthiocarbamate; 0-(4'-acetylphenyl)-N-methyl, N'- ethylthiocarbamate;

4-acetoxyacetophenone;

4-trifluoroacetoxyacetophenone;

4-trichloroacetoxyacetophenone;

2-alkyl, 4-acetoxyacetophenone;

2,3-dialkyl, 4-acetoxyacetophenone;

2,3-dihalo, 4-acetoxyacetophenone;

2-halo, 4-acetoxyacetophenone;

2-alkyl, 4-trichloroacetoxyacetophenone; 2-alkyl, 4-trifluoroacetoxyacetophenone;

4-methanesulfonyloxyacetophenone;

4-toluenesulfonyloxyacetophenone;

2-alkyl, 4-methanesulfonyloxyacetophenone;

2-alkyl, 4-toluenesulfonyloxyacetophenone;

2-halo, 4-methanesulfonyloxyacetophenone; and 2-halo, 4-toluenesulfonyloxyacetophenone.

Examples of 4-hydroxyacetophenones deriviatives used in the reactions include the acetophenone precursors of the above-listed 1,3,5-tris(4'-hydroxyaryl)benzenes, as well as:

4-hydroxyacetophenone;

3-alkyl,4-hydroxyacetophenone,

3-halo,4-hydroxyacetophenone;

3-nitro,4-hydroxyacetophenone;

2-alkyl,4-hydroxyacetophenone;

3-alkyl,4-haloacetophenone; and

2-alkyl,6-halo,4-hydroxyacetophenone.

From the foregoing, it is to be understood that the term "1,3,5-tris(4'-hydroxyaryl)benzene" includes 1,3,5- tris(4'-hydroxyphenyl)benzene and substituted 1,3,5- tris(4'-hydroxyphenyl)benzenes. Likewise, the term "4- hydroxyacetophenone derivative" includes 4- hydroxyacetophenone and substituted 4- hydro-xyacetophenones (whereas "4-HAP substituted" or "4- HAP sub" refers to a 4-hydroxyacetophenone derivative wherein the H of the hydroxy group has been substituted by R).

The spirit of the invention may be further

illustrated by the following examples, many apparent variations of which are possible without departing from the spirit thereof. EXAMPLE 1

Preparation of 1,3,5-tris(4'hydroxyphenyl)benzene (THPB) from 4-acetoxyacetophenone (4-AAP)

a) Synthesis of 1,3,5-tris(4'-acetoxyphenyl)benzene (TAPB) from 4-AAP:

4-Acetoxyacetophenone (15.0 g, 0.084 mol), 1,2- dimethoxyethane (15.0 g), and triethyl orthoformate (12.7 g, 0.085 mol) were mixed in a three-necked 250 ml round bottom flask fitted with a thermometer, distillation head, and a Pasteur pipet (for gas introduction). The reaction mixture was cooled to 0°C with an ice bath.

Anhydrous HCl was bubbled into the flask until the solution maintained a temperature of at least 30°C for two hours. The HCl was thereafter shut off, and nitrogen bubbled through the reaction mixture to remove the last traces of HCl therefrom. The reaction mixture was concentrated on a rotary evaporator to a dark oil. A three-fold molar excess of acetic anhydride was added to the crude reaction mixture along with 0.1 molar

equivalents of sodium acetate. The resulting mixture was refluxed for two hours, at which time the solution was cooled to 0°C. Upon cooling, a yellow solid precipitated and was collected via filtration, washed with water, dried, and characterized as 1,3,5-tris (4'- acetoxyphenyl) benzene (TAPB in 60% yield).

b) Hydrolysis of TAPB to THPB;

TAPB prepared as in step (a) was hydrolyzed in a saturated solution of ethonolic potassium hydroxide by contacting the TAPB with the solution and refluxing the reaction mixture for several hours. The reaction mixture was then cooled to room temperature and solids were removed via filtration. The organic layer was discarded and the aqueous layer acidified to a pH of about 4 to 5 to afford a solid (9.8 grams) of crude THPB. EXAMPLE 2

Synthesis of 1,3,5-tris(4'-hydroxyphenyl)benzene (THPB) from 0-(4'-acetylphenyl)N,N'-dimethylthiocarbamate

a) Synthesis of 1,3,5-tris [4'-0-(N,N'- dimethylthiocarbamoyl) phenyl] benzene (TDMTCPB) from 0-(4'-acetylphenyl)-N.N'- dimethylthiocarbamate:

Using the same apparatus as in Example 1, 0-(4'- acetylphenyl)-N,N'-dimethylthiocarbamate (5.0 g, 0.0224 mol) was dissolved in triethyl orthoformate (5.0 g) and chloroform (25.0 g). With the addition of anhydrous HCl, which was bubbled in, the temperature rose to about 55°C. The temperature of the reaction mixture was maintained between 65 and 71°C with an oil bath and the reaction was completed in about 2 hours. Nitrogen was bubbled in to remove traces of HCl, chloroform was removed on a rotary evaporator and the product was dissolved in ethyl acetate and washed with cold water. The organic layer was separated and dried over anhydrous magnesium sulfate.

The magnesium sulfate was removed via filtration.

Concentration of the organic layer afforded crude product (5.0 g). Recrystallization of a sample (0.25 g) with ethanol (4.0 ml) afforded TDMTCPB (0.18 g) (78% yield). ¹Η and ¹³C NMR analyses confirmed that the product was TDMTCPB. b) Hydrolysis of TDMTCPB to THPB:

TDMTCPB prepared as in step (a) (7.7 g, 0.0125 mol) was hydrolyzed by contacting it with a saturated solution of saturated methanolic potassium hydroxide (115 ml). The reaction mixture was refluxed for about 6 hours, cooled to room temperature and washed with

methylene chloride. The organic layer was discarded, and the aqueous layer acidified with dilute HCl to a pH of about 4 to 5, to afford solid THPB (2.1 grams) (47% yield). ¹H and ¹³C NMR analyses confirmed that the product was THPB.

EXAMPLE 3 Preparation of 1,3,5-tris (4'-hydroxyphenyl)benzene (THPB) from 4-hydroxyacetophenone (4-HAP)

a) Mesylation of 4-HAP to 4-

Methanesulfonyloxyacetophenone

(4-HAP MeBylate)

4-Hydroxyacetophenone (4-HAP) (81.6; 0.60 mol) was added to 300 ml of methylene chloride and the mixture was cooled to 10°C. Triethylamine (60.6 g; 0.60 mol) was then added and a solution of methanesulfonyl chloride (69.0 g; 0.60 mol) in 300 ml of methylene chloride was added to the mixture at such a rate that the reaction temperature was maintained at about 10°C. The mixture was agitated overnight at ambient temperature, then additional methanesulfonyl chloride (12.0 g; 0.1 mol) was added and the reaction mixture was heated to 40°C with agitation for 1 hr. The mixture was concentrated in vacuo at about 30°C and the solids were isolated. The solids were slurried in ice water (600 g), filtered and dried to produce a 154.2 g of crude 4-HAP mesylate. In regard to this portion of this Example, reference is made to Finley et al., U.S. Patent No. 4,128,490. b) Trimerization of 4-HAP mesylate to 1,3,5- tris (4'-methanesulfonoxyphenyl)benzene (4-HAP Mesylate Trimer)

Crude 4-HAP mesylate (116.8 g; 0.55 mol), as prepared in step (a) was contacted with methanesulfonyl chloride (68.7 g; 0.60 mol), and methanesulfonic acid (5.8 g; 0.06 mol). This mixture was stirred at 100°C for 40 hours and transferred to a concentration flask with the aid of methylene chloride and concentrated in vacuo to afford a residue (154.8g). A dark liquid (49.2 g) was decanted from the residue and the remaining solid (105.6 g) was triturated with 250 ml of methanol for 5 minutes so as to provide a slurry. The slurry was filtered and the solids washed two times with methanol (2 x 75 ml). The solids were then dried to afford 74.3 g of a brown solid of crude 4-HAP mesylate trimer (81% pure by

normalized LC).

Crude 4-HAP mesylate trimer (30 g; 0.051 mol) was dissolved in 300 ml of hot 1,4-dioxane. The hot solution was filtered to remove particulates and about 115 ml of solvent was removed by distillation. Product was precipitated from the hot solution by the addition of about 50 ml of demineralized water and the slurry was agitated at ambient temperature overnight. The resulting solids were collected by filtration, and washed with 4:1 (v/v) dioxane:water (25ml) and dried to afford 19.1 g of recrystallized 4-HAP mesylate trimer (53.1% yield from 4- HAP). c) Hydrolysis of 4-HAP mesylate trimer to THPB

4-HAP mesylate trimer (18.0 g; .031 mol) prepared as in step (b) was contacted with and methanol (150 ml). While stirring the mixture, a solution of sodium hydroxide (18.0 g; 0.45 mol) in demineralized water (36 ml) was added. The mixture was heated at reflux overnight, then cooled to ambient temperature. The mixture was then acidified with concentrated HCl, to a pH of about 4 to 5 and concentrated in vacuo to afford a suspension (93 g). The suspension was cooled in an ice bath, diluted with demineralized water (50 ml), and the solids were isolated by filtration. The isolated solids were washed with water (25 ml) and dried, resulting in 13.3 g of a purple solid (88% pure by normalized LC). To remove color, the solid (12.7 g) was digested in a 10% (w/w) aqueous solution of sodium hydroxide (100 ml to form a dark green solution which was washed with dimethyl ether (50 ml) and acidified to a pH of about 4.0 to 5.0 with concentrated HCl to produce a solid which

precipitated out of solution. The precipitated solid was filtered, washed with water, and dried to give 11.1 g of grey solid crude THPB (88% pure).

A sample of the crude THPB (9.58 g) was dissolved in hot methanol (22 ml) and filtered. A solid was re-precipitated with methylene chloride (150 ml) on a steam bath, filtered and dried yielding a lavender solid (4.57 g). The isolated solid was dissolved in hot acetic acid (15 ml) and precipitated with demineralized water (40 ml) on a steam bath. The solids were then filtered, washed with 4:1 water:acetic acid and dried to give 3.71 g of off-white solid (38.7% yield from 4-HAP mesylate trimer, 98% purity by normalized LC).

EXAMPLE 4

Trimerization of 4-methanesulfonyloxyacetophenone (4-HAP mesylate) to 1,3,5 tris (4'-methanesulfonoxyphenyl)benzene (4-HAP mesylate trimer)

4-HAP mesylate (9.6 g) was contacted with

methanesulfonic acid (9.6 g) and methanesulfonylchloride (5.7 g). The reaction mixture was stirred for three days, heated to 60°C and stirred overnight, poured into ice (50 g) and neutralized with NaHCO₃. The mixture was

partitioned with methylene chloride (50 ml) and an insoluble orange-brown solid was filtered from the two phases, a sample of which was tested and found to be 4- HAP mesylate trimer (96% by area LC). EXAMPLE 5

Synthesis of 1,3,5-tris(4'-methanesulfonoxyphenyl) benzene

(4-HAP mesylate trimer) from

4-methanesulfonyloxyacetophenone (4-HAP mesylate)

4-HAP mesylate (9.6 g; 45 mmol) was contacted with methanesulfonyl chloride (5.8 g; 50 mmol) and methane sulfonic acid (0.5 g; 5 mmol). The mixture was heated at 95-105°C for about 18 hours. A sample of the resultant dark brown pasty suspension was tested and found to be 86% 4-HAP mesylate trimer (by normalized LC). The suspension was cooled, quenched in methanol (25 ml), transferred to a concentration flask with methylene chloride and concentrated to give a dark brown solid (26.9 g). The solid was triturated in methanol (3 x 25 ml), filtered, washed twice with methanol (2 x 12.5 ml), and then vacuum dried to give 6.1 g of brown solid (95.3% pure 4-HAP mesylate trimer by normalized LC).

EXAMPLE 6

Hydrolysis of 1,3,5-tris(4'- methanesulfonoxyphenyl)benzene (4-HAP mesylate trimer) to

1,3,5-tris(4'-hydroxyphenyl)benzene (THPB)

4-HAP mesylate trimer (1.7 mmol) was contacted with NaOH (25 mmol) in methanol (8 ml) and H₂O (2 ml). The mixture was heated at reflux overnight resulting in a dark solution which was vacuum concentrated and residue partitioned between methylene chloride and water. The water was acidified with acetic acid to a pH of about 4 to 5 and extracted with ether (3 x 50 ml). The combined ether layers were vacuum concentrated giving a dark brown oil (2.0 g) which was filtered through silica (15 g) with 1:1 methylene chloride: ethyl acetate (4 x 40 ml) and then concentrated to give a dark brown oil (1.32 g). This oil was triturated with methylene chloride (10 ml) and filtered giving 0.2 g of brown solid (THPB) (M.P. 224- 228°C) (33% yield). EXAMPLE 7

Preparation of 1,3,5-tris(4'- methanesulfonoxyphenyl)benzene from

4-methanesulfonyloxyacetophenone

A reaction mixture of 4- methanesulfonyloxyacetophenone (9.6 g; 45 mmol),

methanesulfonyl chloride (5.2 g; 45 mmol) and

methanesulfonic acid (1.9 g; 20 mmol) was heated at 60°C for 7 days, cooled to room temperature and poured over ice (50 g). The reaction flask was rinsed with methylene chloride (25 ml) and the wash was added to the ice, to form an aqueous mixture. The pH of the aqueous mixture was adjusted to basic with sodium carbonate causing

1,3,5-tris (4'-methanesulfonoxyphenyl) benzene to

precipitate. The precipitate was isolated by filtration to afford, after drying, 2.5 g of product. EXAMPLE 8

Preparation of 4-Acetoxyacetophenone from 4- hydroxyacetophenone (4-HAP)

A solution of 136.2 g (1.0 mol) of 4- hydroxyacetophenone and 400 ml of acetic anhydride was heated at reflux for 3 hours under a nitrogen atmosphere. The acetic acid and acetic anhydride was distilled in vacuo (30-41°C, 2.6 mm Hg). The remaining oil was then distilled in vacuo (132-134°C, 2.0 mm Hg) to yield 169.7 g (95.2%) of white crystals identified as 4- acetoxyacetophenone.

EXAMPLE 9

Preparation of 0-(4'-acetophenyl)-N,N'- dimethylthiocarbamate by reaction of

4-hydroxyacetophenone (4-HAP) with N,N'- dimethylthiocarbamoylchloride

A 5 liter flask equipped with a mechanical stirrer was charged with KOH (123 g, 2.2 mol) and methanol (500 ml). The solution was cooled in ice, 4- hydroxyacetophenone (272 g, 2.0

mol) added and the reaction mixture stirred for 0.25 hours. N,N'-Dimethylthiocarbamoylchloride

(274 g, 2.2 mol) was added and the reaction mixture gradually warmed to room temperature. An exothermic reaction was observed and a solid precipitated. After stirring the reaction mixture for an additional 0.5 hours, water (3 1) was added. The contents of the flask were cooled in ice, and the ensuing precipitate was collected via filtration and washed with water. Drying of the solid in vacuo (150 mm Hg) at 50°C. afforded 382 g (85.7% yield) of 0-(4'-acetophenyl)N,N'- dimethylthiocarbamate. (99% pure HPLC).

In regard to this Example, reference is made to U.S. Patent No. 4,794,205.

EXAMPLE 10

One Step Conversion of 4-Hydroxyacetophenone to

1,3,5-tris(4'-hydroxyphenyl)benzene (THPB) 4-Hydroxyacetophenone (6.8 g; 0.05 mol) was placed under nitrogen atmosphere in a dry 3 neck 100 ml round bottomed flask equipped with a condenser and a magnetic stirrer. Anhydrous ethanol (50 ml) was added and the reaction mixture was stirred for 5 minutes.

Tetrachlorosilane (8.5 g; 0.05 mol; 6.0 ml) was then added dropwise with a syringe. The reaction mixture was stirred at room temperature for 72 hours and poured into water (200 ml) to afford a reddish brown solid (7.9 g). HPLC analysis of the crude product revealed it to be THPB (64.4% pure) (86% yield).

Having described in detail preferred embodiments of the present invention, it is to be understood that the invention defined by the claims is not to be limited by particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit of the present invention.

Claims

WHAT IS CLAIMED IS:

1. A compound of the formula (I) :

wherein R¹ is hydrogen, C₁-C₁₂ alkyl, C₃-C₆ cycloalkyl, phenyl, halogen, nitro, C₁-C₁₂ alkyl sulfonyl or aromatic sulfonyl, x is an integer from 1 to 4, and, when x is greater than 1, each R¹ substituent can be the same or different, and R is

wherein each of R² and R³ is a C₁-C₂₀ alkyl group, a substituted alkyl group, an aromatic, or a substituted aromatic, and R² and R³ can be the same or different.

2. The compound of claim 1 wherein R is

3. The compound of claim 1 wherein R is

4. The compound of claim 1 wherein R is

5. The compound of any one of claims 2, 3 or 4 wherein R² and/or R³ each is the same or different and each is a C₁-C₅ alkyl, a C₁-C₅ alkyl substituted by one or more halogen and/or nitro, an aromatic which is phenyl or a substituted aromatic which is tosyl, tolyl, cumenyl, xylyl, mesityl, halo-substituted, or nitro-substituted.

6. The compound of claim 5, wherein R¹ is hydrogen, methyl, ethyl, chloro, fluoro, bromo, nitro, C₁-C₅ alkyl sulfonyl, or an aromatic sulfonyl which is tosyl.

7. The compound of claim 6, wherein R¹ is hydrogen, x is 1 and R² and/or R³ are each the same or different and each is -CH₃, -C₂H₅, -CF₃, -CCl₃ or phenyl.

8. The compound of claim 7, wherein R² and/or R³ are each methyl.

9. The compound of claim 2 wherein the compound of formula (I) is 1,3,5-tris(4'-acetoxyphenyl)benzene.

10. The compound of claim 3 which is 1,3,5-tris (4'- methanesulfonoxyphenyl) benzene.

11. The compound of claim 4 which is 1,3,5-tris [4'- 0-(N,N'-dimethylthiocarbamoyl)phenyl]benzene.

12. A process for the preparation of a compound of a formula (I):

wherein R¹ is hydrogen, C₁-C₁₂ alkyl, a C₃-C₆ cycloalkyl, phenyl, halogen, nitro, C₁-C₁₂ alkyl sulfonyl or aromatic sulfonyl, x is an integer from 1 to 4, and when x is greater than 1 each R¹ substituent can be the same or different, and R is

each of R² and R³ is an alkyl group, a substituted alkyl group or an aromatic, or a substituted aromatic and R² and R³ can be the same or different, said process comprising subjecting to trimerizing conditions a compound of formula (II):

wherein R¹, x and R are as defined above, to form the compound of formula (I).

13. The process of claim 12 further comprising subjecting the compound of formula (I) to hydrolyzing conditions to form a 1,3,5-tris (4'-hydroxyphenyl) benzene derivative of the formula

14. The process of claim 12 wherein R is

15. The process of claim 12 wherein R is

16. The process of claim 12 wherein R is

17. The process of any one of claims 14, 15 or 16, wherein R² and/or R³ each is the same or different and each is a C₁-C₅ alkyl substituted by one or more halogen and/or nitro, an aromatic which is phenyl or a

substituted aromatic which is tosyl, tolyl, cumenyl, xylyl, mesityl, halo-substituted, or nitro-substituted.

18. The proces of claim 17, wherein R¹ is hydrogen, methyl, ethyl, chloro, fluoro, bromo, nitro, C₁-C₅ alkyl sulfonyl, or an aromatic sulfonyl which is tosyl.

19. The process of claim 18, wherein R¹ is hydrogen, x is 1 and R² and/or R³ are each the same or different and each is -CH₃, -C₂H₅, -CF₃, -CCl₃ or phenyl.

20. The process of claim 19, wherein R² and/or R³ are each methyl.

21. The process of claim 13 wherein the trimerizing conditions include contacting the compound of formula (II) with an acidic medium, and the hydrolyzing

conditions include contacting the compound of formula (I) with a basic medium or an acidic medium.

22. The process of claim 21 wherein R is

the acidic medium includes HCl, the basic medium is NaOH or KOH in methanol or ethanol; x is 1, and R¹ is hydrogen.

23. The process of claim 22 wherein the compound of formula (II) is 4'-acetoxyacetophenone.

24. The process of claim 21 wherein R is

(

the acidic medium includes HCl, the basic medium is NaOH or KOH in methanol or ethanol, x is 1, and R¹ is hydrogen.

25. The process of claim 24 wherein the compound of formula (II) is 0-(4'-acetylphenyl)-N,N'- dimethylthiocarbamate.

26. The process of claim 21 wherein R is

the acidic medium comprises a R²- sulfonyl halide or R²- sulfonyl anhydride and a R²- sulfonic acid.

27. The process of claim 26 wherein R² is CH₃-, or p- CH₃-C₆H₄-SO₂- , the sulfonyl halide is methanesulfonyl chloride or tosyl chloride, the sulfonic acid is

methanesulfonic acid or p-toluenesulfonic acid, x is 1, and R¹ is hydrogen.

28. The process of claim 27 wherein the compound of formula (II) is 4-methanesulfonyloxyacetophenone, the sulfonyl halide is methanesulfonyl chloride, the sulfonic acid is methanesulfonic acid; and the basic medium includes NaOH or KOH in methanol or ethanol.

29. The process of claim 12 wherein the compound of formula (I) is 1,3,5-tris (4'-acetoxyphenyl) benzene.

30. The process of claim 12 wherein the compound of formula (I) is 1,3,5-tris(4'- methanesulfonoxyphenyl)benzene.

31. The process of claim 12 wherein the compound of formula (I) is 1,3,5-tris[4'-0-(N,N'- dimethylthiocarbamoyl)phenyl] benzene.

32. The process of claim 29, 30 or 31 wherein the compound of formula (I) is hydrolyzed to 1,3,5-tris (4'- hydroxyphenyl) benzene.

33. The process of claim 12 further comprising preparing the compound of formula (II) by contacting, under reaction conditions, a 4-hydroxyacetophenone derivative of the formula

wherein R¹ and x are as defined above, with a compound of formula R^p wherein R^p comprises

or

wherein each of R² and R³ are as defined above and, X is a halogen.

34. The process of claim 33 further comprising subjecting the compound of formula (I) to hydrolyzing conditions to form a compound formula:

wherein R¹ and x are as defined above.

35. The process of claim 34 wherein the compound of formula (II) is not isolated before trimerizing.

36. The process of claim 34 wherein the compound of formula (I) is 1,3,5-tris (4'-acetoxyphenyl) benzene.

37. The process of claim 34 wherein the compound of formula (I) is 1,3,5-tris (4'- methanesulfonoxyphenyl) benzene.

38. The process of claim 34 wherein the compound of formula (I) is 1,3,5-tris[4'-0-

(N,N'dimethylthiocarbamoyl)phenyl]benzene.

39. A process for the preparation of a compound of a formula (I):

each of R² and R³ is an alkyl group, a substituted alkyl group or an aromatic, or a substituted aromatic and R² and R³ can be the same or different, said process comprising contacting a compound of formula (II):

wherein R¹, x and R are as defined above, with a

halosilane to form the compound of formula (I).

40. The process of claim 39 further comprising subjecting the compound of formula (I) to hydrolyzing conditions to form a 1,3,5-tris (4'-hydroxyphenyl) benzene derivative of the formula

41. The process of claim 39 further comprising preparing the compound of formula (II) by contacting, under reaction conditions, a 4-hydroxyacetophenone derivative of the formula

Λ

or

wherein each of R² and R³ are as defined above and, X is a halogen.

42. The process of claim 41 further comprising subjecting the compound of formula (I) to hydrolyzing conditions to form a 1,3,5-tris(4'-hydroxyphenyl)benzene derivative of the formula

43. The process of any one of claims 39, 40, 41 or 42 wherein the halosilane is tetrachlorosilane.

44. A process for the preparation of a compound of formula (IA):

A

wherein R¹ is hydrogen, a C₁-C₁₂ alkyl, a C₃-C₆ cycloalkyl, phenyl, halogen, nitro, C₁-C₁₂ alkyl sulfonyl or aromatic sulfonyl, x is an integer from 1 to 4, and when x is greater than 1, each R¹ substituent can be the same or different, said process comprising contacting a compound of formula (IIA).

wherein R¹ and x are as defined above, with a halosilane.

45. The process of claim 44 wherein the halosilane is tetrachlorosilane.

46. The process of claim 45 wherein R¹ is hydrogen and x is 1.