A process for the manufacture of (ª‰:ª‰:ª‰-trihalogeno-ethylidene)-ether esters of ª‰-substituted pyruvic acids

摘要

b 1:b 1:b 1-Trihalogenethylidene-ether esters of a b -substituted pyruvic acid of the formula FORM:0592283/IV/1 are prepared by heating the b -substituted pyruvic acid or alkyl ester thereof with an aldehyde of the formula CHO-CX3, wherein X is chlorine or bromine and R is a tertiary alkyl radical, an alicyclic radicle or a phenyl or naphthyl group which may be substituted. In the examples: (1) ethyl b -tertiary valerylpyruvate and chloral are reacted together to give the b 1:b 1:b 1-trichlorethylidene ether ester of b -tertiary pyruvic acid; (2) ethyl b -(p-chlorobenzoyl)-pyruvate and chloral are reacted to give the same ether ester of b -(p-chlorobenzoyl)-pyruvic acid. Specification 588,108 is referred to.