Abstract: Novel molecular compounds containing carboxylic acid derivatives represented by general formula (I) or (II) as the constituent compound and exhibiting excellent performances in various technical fields including selective separation of useful substances, chemical stabilization, nonvolatilization, prolongation of release and powderization, wherein X is (CH2)n or p-phenylene; n is 0, 1, 2 or 3; R1 to R8 and R13 to R20 are each hydrogen, C1-C6 alkyl, C2-C4 alkenyl, phenyl optionally substituted with C1-C6 alkyl, halogeno or C1-C6 alkoxy; and R9 to R12 and R21 to R24 are each hydrogen, C1-C6 alkyl, C2-C4 alkenyl, C11-C12 aralkyl or an alkali metal.

Abstract: A process for producing high quality TPA suitable for PET feedstock material from recycled polyester. The process includes the steps of depolymerizing the polyester to form DMT; separating the DMT from secondary materials; and hydrolyzing the DMT to form TPA. In a preferred embodiment of the invention the recycled polyester is contacted with a component monomer or oligomer thereof to liquefy the polyester prior to depolymerizing the polyester.

Abstract: 6-Alkoxycarbonylmethyl-4H-1,3-dioxin-4-one derivatives are produced by reacting a 6-halomethyl-4H-1,3-dioxin-4-one derivative with carbon monoxide and an alcohol or water, and 3-oxopentanedicarboxylic acid esters are further produced by reacting the above derivatives with an alcohol or water. Such a process can produce 3-oxopentanedicarboxylic acid esters in an easy and simple and efficient manner.

Abstract: Compounds containing unsaturated aliphatic moieties which are linked to each other by a tertiary oxycarbonyl containing acyclic moiety are basis for compositions which are cured to polymer networks which are thermally decomposable to provide residue which can be dissolved to allow repair of inoperative assemblies by replacement of inoperative components or recovery or recycling of operative elements which are affixed in assemblies by the cured compositions.

Abstract: A pressure process for preparing a hydroxyalkyl ester monomer and oligomer that can be used to prepare a polyester such as polyethylene terephthalate (PET) is disclosed. The process includes the steps of reacting, by ethoxylation, dicarboxylic acid and alkylene oxide in the presence of a compressed gas medium to form a specified mixture of monohydroxyalkyl ester and bishydroxyalkyl ester. The reaction pressure is such that the density of the gas medium is greater than or equal to half the critical density of the compressed gas medium. The mole ratio of the alkylene oxide to the dicarboxylic acid is less than about 2:1, and preferably 1.1:1.2. The DP of all reaction products is less than 5. The reactant product may be polymerized into a polyester. The process may optionally employ catalysts such as amines or amino acids. The compressed gas medium can be a solvent and an optional cosolvent. The temperature of reaction is from about 100° C. to 240° C. at a pressure of 50-5000 psi.

Abstract: There is herein disclosed a process for efficiently preparing, from an &agr;-hydroxycarboxylic amide and an alcohol in an industrially advantageous manner, an &agr;-hydroxycarboxylate which is useful as any of raw materials for solvents, food additives, perfumes, various organic medicines and the like. According to the present invention, there is provided a process for preparing an &agr;-hydroxycarboxylate which comprises the step of reacting an &agr;-hydroxycarboxylic amide and an alcohol in the presence of a catalyst in a liquid phase, while an ammonia concentration in a reaction solution is maintained at 0.1% by weight or less by discharging generated ammonia as a gas into a gaseous phase.

Abstract: A tetraester of 3,3′,4,4′-biphenyltetracarboxylic acid is advantageously prepared by a process composed of a step of dimerizing an o-phthalic diester in the presence of a catalyst comprising a powdery palladium salt having a specific surface area of at least 0.5 m2/g and a basic bidentate ligand compound and one or more steps of continuing the dimerization after supplemental addition of at least one of the powdery palladium salt and the basic bidentate ligand compound.

Abstract: A catalytic process for production of biphenyl and its derivatives by coupling of substituted or unsubstituted monoaryl compounds in the presence of a catalytic system comprising at least one Pd (II) compound and a strong acid or a mixture of acids. The process provides high conversions and high selectivity under mild temperature conditions and short reaction times. The strong acid or mixture of acids has a Hammett acidity of less than about -10, and contains a predominant amount of counterions which form a weak ligand complex with palladium (II). The method is highly selective to formation of desired biaryl isomers, such as 4,4'-isomers, and allows control of the relative amounts of isomers of biaryl compounds and substituted monoaryl compounds in the final product.

Abstract: Method for producing an alkyl carboxylate, in which a carboxylic acid and an alcohol are esterified by reaction in the presence of an acid catalyst, by removing water in a dehydration step established halfway in the esterification reaction using a solid acid catalyst as the acid catalyst, and restarting the esterification reaction to complete the esterification reaction.

Abstract: The present invention relates to a highly enantioselective process for the preparation of enantiomerically pure cyclopentane- and -pentene .beta.-amino acids of the general formula (I) ##STR1## in which A and L, A and D or E and L, D and E, R.sup.2, R.sup.3, T and R.sup.1 have the meaning given in the description.

Abstract: There is described a process for improving the yield of diester monomer recovered from the depolymerization of polyethylene terephthalate by converting a mixture of dimethyl terephthalate and methylhydroxyethyl terephthalate to predominantly dimethyl terephthalate by treating that mixture with a mixture of an alcohol and an alkali metal hydroxide at a temperature up to the boiling point of the alcohol.

Abstract: A process for the preparation of a compound of formula (I) wherein R.sub.2 is a (C.sub.1 -C.sub.6)alkyl, (C.sub.2 -C.sub.6)alkenyl, (C.sub.2 -C.sub.6)alkynyl, phenyl(C.sub.1 -C.sub.6)alkyl, heteroaryl(C.sub.1 -C.sub.6)alkyl, cycloalkyl(C.sub.1 -C.sub.6)alkyl or cycloalkenyl(C.sub.1 -C.sub.6)alkyl group, any one of which may be optionally substituted by one or more substituents selected from (C.sub.1 -C.sub.6)alkyl, (C.sub.1 -C.sub.6)alkyl, --S(C.sub.1 -C.sub.6)alkyl, halo and cyano (--CN); and R.sub.7 is a carboxylic acid protecting group, which process comprises the internal molecular rearrangement of an allyl carboxylate compound of formula (II) wherein R.sub.2 and R.sub.7 are as defined in relation to formula (I) to form the desired compound of formula (I). Compounds (I) are intermediates for the preparation of Matrix metaloproteinase inhibitors.

Abstract: The present invention relates to a process for the preparation of compounds of the formula (1)R.sup.1 R.sup.2 R.sup.3 R.sup.4 R.sup.5 ArCOOR (1)in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are identical or different and are hydrogen, a halogen, an alkyl or alkoxy group having 1 to 6 carbon atoms or OR, NHR, NR.sub.2, SR or COOR, in which R is an alkyl radical having 1 to 4 carbon atoms, Ar is an aryl radical having 6 to 12 carbon atoms and the radical R shown in formula (1) has the above meaning, by reacting a compound of the formula (2)R.sup.1 R.sup.2 R.sup.3 R.sup.4 R.sup.5 ArCOOH (2)in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are identical or different and are hydrogen, a halogen, an alkyl or alkoxy group having 1 to 6 carbon atoms, OH, NH.sub.2, NHR, SH or COOH and Ar has the same meaning as in formula (1), with a sulfate of the formula (RO).sub.2 SO.sub.2, in which R has the above meaning, in the presence of a water-insoluble tertiary amine and water at a temperature of 10.degree.

Abstract: An improved process for recovering depolymerization products from polymers such as polyesters, polyamides, and polyesteramides, especially when the starting polymer content is less than about 98%. The depolymerization and vapor phase recovery of monomers and other reaction products are conducted in the presence of a solid support.

Abstract: A thermosetting composition which comprises:(D) a self-crosslinking compound having in the molecule (a) one or more functional groups of the formula (2): ##STR1## wherein R.sup.5, R.sup.6 and R.sup.7 are each hydrogen or an organic group of 1 to 18 carbons, R.sup.8 is an organic group of 1 to 18 carbons, Y.sup.2 is oxygen or sulfur, or R.sup.7 and R.sup.8 are bonded with each other to form a heterocyclic structure which comprises Y.sup.2 as the heteroatom component; and (b) one or more reactive functional groups which can form a chemical bond with carboxyl functional groups which are regenerated from (a) by heating; (C) optionally, a thermal latent acid catalyst which is activated during curing of the composition by heating; (A) optionally, a compound having in the molecule two or more functional groups of the formula (1): ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are each hydrogen or an organic group of 1 to 18 carbons, R.sup.4 is an organic group of 1 to 18 carbons, Y.sup.1 is oxygen or sulfur, or R.

Abstract: An improved process for recovering reaction products from polymers such as polyesters or polyamides, especially those having a desired polymer level below about 98%. The process involves depolymerization and vapor phase extraction of monomers in the presence of a solid support.

Abstract: Disclosed is a process for the preparation of 4,4'-stilbenedicarboxylate esters by a 4-step process starting with an alkyl p-formylbenzoate and utilizing intermediate phosphite and phosphonate compounds. The steps comprise(1) preparing an alkyl p-(hydroxymethyl)benzoate by hydrogenating an alkyl p-formylbenzoate;(2) contacting the alkyl p-(hydroxymethyl)benzoate of step (1) with a trialkyl phosphite to obtain a phosphite ester compound having the formula: ##STR1## (3) contacting the phosphite ester of step (2) with a catalytic amount of iodine to rearrange the phosphite ester to the corresponding phosphonate ester;and(4) contacting the phosphonate ester compound of step (3) with an alkyl p-formylbenzoate in the presence of an alkali metal alkoxide and an inert solvent to obtain the dialkyl 4,4'-stilbenedicarboxylate.

Abstract: Disclosed is a process for the preparation of 4,4'-stilbenedicarboxylate esters by a 3-step process utilizing p-toluic acid, an alkyl p-formylbenzoate and a trialkyl phosphite. The steps comprise(1) preparing p-(chloromethyl)benzoic acid by chlorinating p-toluic acid with sulfuryl chloride in the presence of a free radical initiator and chlorobenzene or dichlorobenzene;(2) contacting the p-(chloromethyl)benzoic acid of step (1) with a trialkyl phosphite to obtain a phosphonate compound; and(3) contacting the phosphonate ester compound of step (2) with an alkyl p-formylbenzoate in the presence of an alkali metal alkoxide and an inert solvent to obtain the dialkyl 4,4'-stilbenedicarboxylate.

Abstract: The invention relates to a method of reacting alkyl carboxylate chlorides and/or carboxylic dichlorides dissolved in corresponding diaikyl carboxylates with the corresponding alkanol at temperatures ranging from 60.degree. to 300.degree. C., in which the resultant hydrogen chloride remains in the reaction mixture.

Abstract: An industrial process for producing O,O'-diacyltartaric anhydride with high purity and high efficiency is disclosed. According to the process of the invention, a carboxylic acid of the formula (I):R.sup.1 COOH (I)(wherein R.sup.1 represents C.sub.1 -C.sub.4 alkyl group; phenyl group; or phenyl group substituted with 1-5 C.sub.1 -C.sub.4 alkyl groups or with 1-5 halogen atoms) is reacted with tartaric acid in the presence of a chlorinating agent.

Abstract: A process for recovering dimethyl terephthalate (DMT) is disclosed. The process includes the steps of: (a) providing a DMT stream, the DMT stream including DMT, catalyst, and ethylene glycol; (b) adding a solvent to the DMT stream, the solvent being immiscible with water and miscible with DMT; (c) adding water to the DMT stream; and (d) forming two phases, a first phase of the solvent and DMT, and a second phase of water, ethylene glycol, and catalyst.

Abstract: A process for recycling by-products produced from a process for the manufacture of polyethylene terephthalate is disclosed. The process includes the steps of: (a) providing ethylene glycol distillation bottoms from an ethylene glycol recovery unit associated with the manufacture of polyethylene terephthalate, the bottoms containing an alkali metal organic salt produced during the manufacture of polyethylene terephthalate, the alkali metal organic salt being in excess of about 100 ppm of the bottoms; (b) stripping the alkali metal from the organic acid by use of a strong acid; and (c) depolymerizing the organic acid.

Abstract: Disclosed is a method of making a 4-substituted phthalic anhydride. A halomaleic (including halofumaric anhydride (or the acid or ester thereof) is made by the reaction of-maleic anhydride with chlorine or bromine. The halomaleic anhydride is reacted with a conjugated diene to form a first cycloadduct having the formula ##STR1## The first cycloadduct is heated to eliminate HX and produce a second cycloadduct having the formula ##STR2## The second cyclo adduct is dehydrogenated to produce a 4substituted phthalic anhydride which has the formula ##STR3## where R.sub.1, R.sub.2, and R.sub.4 are preferably H and R.sub.3 is preferably Cl or F.

Abstract: A process for the production of terephthalate diesters having the following formula (I). ##STR1## Substituents R and R' are the same or different and represent a straight chain, branched or cyclic aliphatic group, an aromatic group, an alkaryl group or an aralkyl group, each group having from 6 to 20 carbon atoms. The process involves reacting a terephthalate polyester with a high molecular weight alcohol or a mixture of high molecular weight alcohols each having from 6 to 20 carbon atoms, in the presence of a catalyst and recovering the desired compound according to formula (I). This process is particularly useful for recycling scrap terephthalate polyester products such as those produced from polyethylene terephthalate (PET), crystallized polyethylene terephthalate (CPET), glycol-modified polyethylene terephthalate copolyester (PETG), polybutylene terephthalate (PBT), polycyclohexanedimethylene terephthalate (PCT), as well as the acid- and glycol-modified copolyesters of PCT, respectively PCTA and PCTG.

Abstract: A 3,4,3',4'-substituted biphenyl compound represented by the general formula (II): ##STR1## wherein, one of R.sup.1 and R.sup.2 is a -CH.sub.3 group and the one other is a --COOR.sup.5 group, --COOH group, or --COCl group, and one of R.sup.3 and R.sup.4 is a -CH.sub.3 group and the other one is a --COOR.sup.5 group, --COOH group, or --COCl group, is produced by the steps of oxidatively coupling an o-toluic acid alkyl ester in the presence of a catalyst containing a mixture of palladium salts with 1,10-phenanthroline or .alpha.,.alpha.'-bipyridine, a chelating product of a palladium salt with 1,10-phenanthroline, or a chelating products of a palladium salt with .alpha.,.alpha.

Abstract: Prepolymer polyols containing mesogenic moieties useful as reactants for the preparation of resinous materials are disclosed. Synthesized by condensing a polyether polyol with bifunctional mesogenic diacids, or diesters, the compounds of the invention are characterized by their reasonably low melt temperature which renders them suitable as additive materials in polymeric molding compositions and as precursors for the preparation of resinous materials.The liquid crystalline properties of the prepolymers of the invention were found to depend on the type and molecular weight of the glycols and on the molar ratio between the glycols and the mesogenic reactant.

Abstract: Disclosed are processes for the preparation of alkyl (alkoxycarbonylcyclohexyl)cyclohexenecarboxylates by the dimerization of alkyl 3-cyclohexenecarboxylates and the dehydrogenation of the alkyl (alkoxycarbonylcyclohexyl) cyclohexenecarboxylates to dialkyl biphenyldicarboxylates. The processes are especially useful for the preparation of dialkyl 4,4'-biphenyldicarboxylates which are intermediates in the preparation of high performance polyesters.

Abstract: A process for producing a dialkyl ester (i.e. BTDE) from its corresponding dianhydride (i.e., BTDA) comprising mixing the dianhydride, an organic solvent, solid catalyst and an alcohol capable of reacting with the dianhydride stirring the solution until the dianhydride and alcohol have reacted to form the dialkyl ester, separating the dialkyl ester from the catalyst and drying the ester to form a solid paticulate product. The product has a purity of over 85%.

Abstract: Allyl end-capped propylene terephthalate polyester oligomers are sulfonated in an aqueous system in the presence of a free radical initiator by a process in which only a part (about 15% to 40%) of the source of bisulfite is added at the start of the sulfonation step with the remainder being added later in that step, in such increments as will permit maintaining a clear single phase, to give sulfinate-containing sulfonated products, following which the sulfinate content is oxidized to give sulfonated end-capped propylene terephthalate polyester oligomers.

Abstract: The invention is concerned with a novel route for making 4,4'-bis(carboalkoxystilbene) derivatives. The process involved is a variation of the Wittig process and allows the compound to be obtained in a less costly and safer way.

Abstract: A ruthenium phosphine complex having catalytic, hydrogenation activity is disclosed. The catalyst as the formula ##STR1## wherein R and R' are the same or different and are C.sub.1 to C.sub.6 linear or branched alkyl; R" is hydrogen or C.sub.1 to C.sub.6 linear or branched alkyl; R.sub.1 is C.sub.1 to C.sub.6 linear or branched alkyl; and n is an integer from 1 to 6.The phosphine complex is particularly useful in the asymmetric hydrogenation of unsaturated carboxylic acids or alkyl esters thereof.

Abstract: A process for the production of terephthalate diesters having the following formula (I). ##STR1## Substituents R and R' are the same or different and represent a straight chain, branched or cyclic aliphatic group, an aromatic group, an alkaryl group or an aralkyl group, each group having from 6 to 20 carbon atoms. The process involves reacting a terephthalate polyester with a high molecular weight alcohol or a mixture of high molecular weight alcohols each having from 6 to 20 carbon atoms, in the presence of a catalyst and recovering the desired compound according to formula (I). This process is particularly useful for recycling scrap terephthalate polyester products such as those produced from polyethylene terephthalate (PET), crystallized polyethylene terephthalate (CPET), glycol-modified polyethylene terephthalate copolyester (PETG), polybutylene terephthalate (PBT), polycyclohexanedimethylene terephthalate (PCT), as well as the acid- and glycol-modified copolyesters of PCT, respectively PCTA and PCTG.

Abstract: This invention relates to spiro-isoquinoline-pyrrolidines and their pharmaceutically acceptable salts thereof, to processes for their preparation, to methods for using the compounds, and to pharmaceutical preparations thereof. The compounds have pharmaceutical properties which render them beneificial for the prevention or treatment of diabetes mellitus associated complications.

Abstract: A process for the preparation of 3,3',4,4'-biphenyltetracarboxylic acid salt by the dehalodimerization of a 4-halophthalic acid salt. The process uses hydroxylamine or one of its salts as the reducing agent in an alkaline solution, preferably of pH 10 or above, and palladium catalyst. The reaction is carried out between 50.degree. and 150.degree. C.

Abstract: Biphenyl tetracarboxlic acid esters and derivatives thereof are prepared by the coupling reaction of 4-halogen substituted o-benzenedicarboxylic acid ester, carried out in an aprotic polar solvent in the presence of a pre-prepared triphenylphosphine-nickel chloride or trialkylphosphine-nickel chloride catalyst, zinc powder as the reducing agent, and an alkali metal halide promoting agent. The ester may be hydrolyzed in basic solution to afford the corresponding acid. The acid may be heated or boiled with acetic anhydride to afford the biphenyl dianhydride.

Abstract: Polyfunctional hexasubstituted benzene derivatives wherein at least three of the substituents are saturated carbon chains having from 1 to 21 carbon atoms and functional groups containing hetero functionalities at the ends of the carbon chains and the remainder of the 6 substituents are either saturated carbon chains containing from 1 to 21 carbon atoms or saturated carbon chains containing from 1 to 21 carbon atoms having a functional group including a hetero functional group containing N, O, S, P, or Si at the end of the chains. These derivatives are made by reacting a disubstituted alkyne wherein one or both of the substituents are saturated carbon chains having 1 to 21 carbon atoms to which hetero functional groups are attached with a palladium catalyst and isolating the resulting hexasubstituted benzene derivative.

Abstract: An improved method for making biaryl compounds is disclosed, in which an aromatic acid halide having at least one strong electron-withdrawing group attached to or within the aromatic ring is reacted with at least one polysilane in the presence of an effective amount of a transition metal catalyst.

Abstract: Process for the preparation of tert-alkyl esters of the formula I ##STR1## in which m is 1 or 2, R is C.sub.4 -C.sub.12 tert-alkyl and X, if m=1, is unsubstituted or halogen-substituted alkyl, cycloalkyl, unsubstituted or substituted aryl or aralkyl, or an aromatic heterocyclic radical and, if m=2, is a direct bond, --CH.sub.2).sub.n, in which n can be an integer from 1 to 8, or 1,2-, 1,3- or 1,4-phenylene, by reaction of an ester of the formula II ##STR2## in which R.sub.1 is methyl or ethyl, with an alcohol ROH in the presence of a catalyst customary for transesterifications.

Abstract: An improved method of recovering a palladium catalyst from a liquid reaction mixture having been produced by oxidative coupling reaction of an aromatic compound in the presence of a catalyst containing palladium(II) salt is disclosed. The improved method comprises heating the liquid reaction mixture under stirring at a temperature of 180.degree. to 280.degree. C. in an atmosphere containing hydrogen gas at a partial pressure of 5 to 60 kg/cm.sup.2 whereby reducing the catalyst in the reaction mixture and precipitating a metallic palladium from the reaction mixture.

Abstract: An end carboxyl bearing reactive vinyl monomer represented by the formula: ##STR1## wherein R.sub.1 is hydrogen or methyl group; R.sub.2 is a bivalent aliphatic hydrocarbon having 2 to 10 carbon atoms, a bivalent alicyclic hydrocarbon having 6 to 7 carbon atoms, phenylene substituted with halogen, sulfo or carboxyl group; A is a repeating unit of the formula: ##STR2## R.sub.3 is ethylene or propylene; R.sub.4 is an alkylene having 2 to 7 carbon atoms; R.sub.5 is an alkylene having 2 to 5 carbon atoms; m is an integer of 1 to 10 and n is an integer of 2 to 50. The present reactive vinyl monomer is very useful as a constituting unit of vinyl resin.

Abstract: A process of regenerating a palladium salt catalyst comprising, in combination, steps of:(I) heating an organic residue containing a palladium salt catalyst which has been separated from a reaction solution, at a temperature of not lower than 330.degree. C. under an inert gas atmosphere to produce a reduced and thermally decomposed porous product;(II) firing the porous product produced in the step I under an oxygen-containing atmosphere; and(III) treating the product fired in the step II with an acid to produce a palladium salt.

Abstract: Disclosed is a process for producing dimethyl or novel diphenyl derivatives of stilbenedicarboxylic acids from dimethyl toluates or diphenyl toluates and sulfur. The reaction requires an excess of toluate to sulfur of at least about 5:1. In addition hydrogen sulfide is removed from the reaction zone.

Abstract: When a 4-halogenoorthophthalic acid salt is dissolved together with a base in an alkaline aqueous solution and the solution is heated in the presence of a catalyst comprising a noble metal supported on a carrier, a formic acid salt and a small amount of an aliphatic compound containing a hydroxyl group, a 3,3',4,4'-biphenyltetracarboxylic acid salt is obtained in a high yield.

Abstract: The preparation of 4,4'-dimethylstilbenedicarboxylate by acetylating 4,4'-bis(methoxycarbonyl)benzoin to give 4,4'-bis(methoxycarbonyl)benzoin acetate, selectively reducing 4,4'-bis(methoxycarbonyl)benzoin acetate with hydrogen to give 1,2-bis(4-methoxycarbonylphenyl)ethanol, and subjecting the 1,2-bis(4-methoxycarbonylphenyl)ethanol to either (1) dehydration or (2) acetylation to 1,2-bis(4-carbomethoxyphenyl)-1-acetoxy ethane followed by pyrolysis thereof to give the 4,4'-dimethylstilbenedicarboxylate. In this process, the new compounds 4,4'-bis(methoxycarbonyl)benzoin acetate, 1,2-bis(4-methoxycarbonylphenyl)ethanol, and 1,2-bis(4-carbomethoxyphenyl)-1-acetoxy ethane are produced and the novel preparations thereof are performed.

Abstract: This invention pertains to a new method for killing and controlling worms (Helminths), new formulations for killing and controlling worms in animals, new chemical compounds, and a new synthesis of northern hemisphere intermediates for the synthesis of milbemycin and avermectin macrolides.

Abstract: An olefin, especially an activated olefin, is telomerized by reaction with an arylamine, such as an aniline, in the presence of an alkyl nitrite, a copper catalyst, and a catalytic amount of water and/or acid and in the absence of more than about 0.5 volume part of inert solvent per volume part of olefin.

Abstract: A method for carrying out processes capable of catalysis by protons using as catalyst a stabilized pillared interlayered clay.

Abstract: Carboxylic acid esters are produced by the reaction of a carboxylic acid halide with a carbonate ester in the presence of an initiator. The reaction of a dicarboxylic acid dihalide and a bis(alkyl carbonate) ester produces a polymeric polyester.

Abstract: Provided is a process for preparing a diaryl or a mixture of diaryls represented by any or a combination of the following formulae (II), (III) and (V), characterized in that a diaryliodonium salt represented by the following formula (I) is reacted in a solvent in the presence of a transition metal catalyst and a reducing metal at a temperature in the range of room temperature to 100.degree. C.:[Ar.sub.1 -I.sup..sym. -Ar.sub.2 ]X.sup..crclbar. (I)Ar.sub.1 -Ar.sub.1 (II)Ar.sub.1 -Ar.sub.2 (III)Ar.sub.2 -Ar.sub.2 (IV)wherein Ar.sub.1 and Ar.sub.2, which may be alike or different, are each an aryl group which may have a substituent group or groups and X.sup..crclbar. is a counter ion which is inert to said reaction.

Abstract: A biphenyltetracarboxylic ester, particularly, 3,3',4,4'-biphenyltetracarboxylic tetraester, is prepared in an increased yield by first oxidative coupling, at 140.degree. C. to 260.degree. C., an o-phthalic diester with a molecular oxygen-containing gas, for example, air, in the presence of a catalyst comprising predetermined amounts of a Pd salt, a basic bidentate ligand compound, and a Cu salt to convert a portion of the o-phthalic diester to the corresponding biphenyltetracarboxylic ester and by additionally oxidative coupling in one or more steps, in each step, the remaining portion of o-phthalic diester with a molecular oxygen-containing gas at 140.degree. C. to 260.degree. C. while controlling the composition of the catalyst to an extent such that the entire molar amount of the Pd salt is 0.0001 to 0.01 time that of the o-phthalic diester, the entire molar amount of the ligand compound is 0.5 to 4 times that of the Pd salt and the entire molar amount of the Cu salt is 0.