PROCESSES FOR PRODUCING 2-SUBSTITUTED BENZO[B]THIOPHENE

摘要

A 2-alkylthiobenzaldehyde of general formula (I) is reacted with a halo compound of general formula (II) to produce a 2-substituted benzo¢b!thiophene of general formula (III). (I) wherein R1 means an alkyl group of 1 to 4 carbon atoms. X1CH2Y (II) wherein X1 means Cl or Br; Y means -CO2H, -CO2R, -COR2, -CONH2 or -CN; R2 means an alkyl group of 1 to 4 carbon atoms. (III) wherein Y is as defined above. The process of this invention is of great economic and industrial value, for 2-acetylbenzo¢b!thiophene and 2-benzo¢b!thiophenecarboxylic acid, which are important intermediates for drugs and agricultural chemicals among others, can be obtained in a simple manner, easily and in high yield.