Process for preparing 2-thio-2-substituted-alkanoic acid derivatives
申请人:Sagami Chemical Research Center
公开号:US04245108A1
公开(公告)日:1981-01-13
A process for preparing a 2-thio-2-substituted-alkanoic acid derivative represented by the formula (I) ##STR1## wherein A, R, R.sup.3 and R.sup.4 are as defined hereinafter, which comprises condensing an aldehyde compound of the formula (V) A--CHO (V) wherein A is as defined hereinafter, with a haloform of the formula CHX.sub.3 wherein X is as defined hereinafter and a mercaptan compound of the formula (IV) R.sup.3 SH (IV) wherein R.sup.3 is as defined hereinafter, in the presence of a base to produce a 2-(arylthio or alkylthio)-2-substituted-acetic acid of the formula (III) ##STR2## wherein A and R.sup.3 are as defined hereinafter, and reacting the resulting 2-(arylthio or alkylthio)-2-substituted-acetic acid of the formula (III) with an alkylating agent represented by the formula (II) RZ (II) wherein R and Z are as defined hereinafter, in the presence of at least 2 mols of a base per mol of the 2-(arylthio or alkylthio)-2-substituted-acetic acid, to form the compound of the formula (I) wherein R.sup.4 represents a hydrogen atom and, optionally, converting the resulting compound to the compound of the formula (I) wherein R.sup.4 represents an alkyl group by esterification.