Abstract: A process the preparation of a dithiocarboxylic esters comprises reacting a carboxylic acid compound of formula R1(COOH)m, a compound of formula R2AH and phosphorus pentasulfide to produce a compound of structure I. An alternate process comprises reacting a compound of formula R3(COAH)m and a compound of structure II in the presence of a clay catalyst; and treating products of the reaction with a thiating agent to produce a compound of structure III, a compound of structure IV, or a combination of compounds of structure III and structure IV.

Abstract: A process the preparation of a dithiocarboxylic esters comprises reacting a carboxylic acid compound of formula R1(COOH)m, a compound of formula R2AH and phosphorus pentasulfide to produce a compound of structure I.

Abstract: Polycarbonate oligomers are prepared by oxidative carbonylation of a dihydroxyaromatic compound such as bisphenol A in the presence of a catalyst comprising a Group VIII metal such as palladium, an inorganic and/or an organic co-catalyst, a halide source and an alcohol-free solvent comprising at least one liquid aromatic hydrocarbon, optionally in combination with a dipolar aprotic liquid such as N-methylpyrrolidinone. These oligomers may be further polymerized by melt polymerization to precursor polycarbonate oligomers which may be converted to high molecular weight polycarbonates by melt or solid state polymerization.

Abstract: Diaryl carbonates such as diphenyl carbonate are prepared by reaction of hydroxyaromatic compounds such as phenol with oxygen and carbon monoxide in the presence of a catalyst composition comprising a Group VIIIB metal such as palladium or a compound thereof, a bromide source such as a quaternary ammonium or hexaalkylguanidinium bromide and a polyaniline in partially oxidized and partially reduced form. The polyaniline is preferably halide-doped and in the form of a blend with a binder polymer containing ether or ester groups and a complex-forming salt.