Patent ID: 7183419

Claim:
A process for producing compounds represented by the following formula (I), wherein, A, B, C and D in each case independently denote a member selected from the group consisting of a bond, alkylene, substituted alkylene, cycloalkylene, substituted cycloalkylene, arylene, substituted arylene and (—O—(CR 1 R 2 ) m ) x , wherein R 1 and R 2 in each case are independently selected from the group consisting of hydrogen, alkyl, and substituted alkyl, m is an integer from 1 to 10 and x is an integer from 1 to 10, provided that at least one of the units A, B, C or D is other than a bond, said process comprising, (i) reacting a compound represented by the following formula (II), TosO-A-B-C-D-OTos (II) wherein A, B, C and D are each as described with regard to formula (I), and Tos denotes a member selected from the group consisting of p-toluenesulfonyl and trifluoromethanesulfonyl, with a thiophene represented by the following formula (III), wherein, R denotes C 1 –C 18 alkyl, and m denotes H, Li, Na or K, thereby forming an intermediate 3,4-dioxythiophene diester, (ii) saponifying the intermediate 3,4-dioxythiophene diester, thereby forming an intermediate 3,4-dioxythiophene dicarboxylic acid, and (iii) decarboxylating said intermediate 3,4-dioxythiophene dicarboxylic acid, thereby forming the compound represented by formula (I).