GB730599A - Production of carboxylic acid ester - Google Patents

Abstract

Polyesters are prepared by adding chlorocarbonic esters of polyhydroxy compounds to a mixture of about the equivalent amount, with reference to the chlorocarbonic acid ester groups, of a polycarboxylic acid or of a salt thereof and up to about 1.7 per cent by weight, with reference to the amount of carboxylic acid used, of a tertiary amine or of finely divided copper, iron or palladium and heating the mixture at 90 DEG to 160 DEG C. until no more carbon dioxide escapes. Aliphatic, cycloaliphatic, aromatic, araliphatic and heterocyclic poly-carboxylic acids may be used, e.g. oxalic, succinic, adipic, phthalic, hexahydrophthalic and terephthalic acids. The chloro carbonic acid esters may be of aliphatic, cycloaliphatic or aromatic polyhydroxy compounds such as glycerol, pentaerythritol, glycol and cyclohexanediols. In an example, the bischlorocarbonic ester of 1 : 4-butanediol is added to a solution of sodium adipate using pyridine as catalyst at 100 DEG C., the resulting polyester precipitating in the form of white flocks.ALSO:Carboxylic acid esters are prepared by adding chlorocarbonic acid esters of mono- or poly-hydroxy compounds to a mixture of about the equivalent amount, with reference to the chlorocarbonic acid ester groups, of a carboxylic acid or salt thereof and up to about 1.7 per cent by weight, with reference to the amount of carboxylic acid used, of a tertiary amine or of finely divided copper, iron or palladium and heating the reaction mixture to about 90 DEG to 160 DEG C. until no more carbon dioxide escapes; when the free acid is used, hydrogen chloride is also evolved. Reaction of chlorocarbonic esters of polyhydroxy compounds with poly-carboxylic acids yields polyesters (see Group IV (a)). In examples: (1) 1 : 4 - butanediol - bis - chlorocarbonic acid ester is gradually added to hexahydrobenzoic acid at 90 DEG C., the product being the bishydrobenzoic acid ester of the diol; the chlorocarbonates of glycerol, butane-triol and 1 : 6- or 2 : 5-hexanediol may be used similarly; (2) the chlorocarbonate of 4-chlorobutanol is likewise added to benzoic acid containing copper, yielding 4-chlorobutanol benzoate; chlorbenzoic acid, methoxy-benzoic acid and naphthoic acid may also be used; (3) sec.-butyl chlorocarbonate is added to acetic acid containing pyridine as in (1) to form sec.-butyl acetate; esters of stearic and montanic acids may be prepared in like manner; (4) n-butyl chlorocarbonate is added to aqueous sodium adipate containing pyridine at 100 DEG C. yielding bis-n-butyl adipate; (5) chlorocarbonates of mixed C5-7 sec.- and tert.-alcohols are similarly reacted with aqueous sodium phthalate containing pyridine to yield a mixture of phthalic acid esters. Many other reactants are mentioned, e.g. cyclopentane carboxylic acid, phenylacetic, isonicotinic, oxalic and terephthalic acids, and chlorocarbonates of methanol, glycol, cyclohexanol, pentaerythritol and phenol.