Preparation of 4-Chloro-2-thiophenecarboxylic Acid via Selective Bisulfite Salt Addition Procedure

JW Raggon, JM Welborn, JE Godlewski…

Index: Raggon, Jeffrey W.; Welborn, Jennifer M.; Godlewski, Jane E.; Kelly, Sarah E.; LaCour, Thomas G. Organic Preparations and Procedures International, 1995 , vol. 27, # 2 p. 233 - 236

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Citation Number: 4

Abstract

A key reaction in a proposed synthesis of 4-chloro-2-thiophenecarboxylic acid 6 is the regioselective chlorination of 2-thiophenecarboxaldehyde 1. The chlorination of 1 in the presence of excess AlC1, to give 6 has been reported.'However, the product was separated from the undesired positional chloro isomers by column chromatography. Herein we would like to report a more general method of isolating 6 that is amenable to large-scale ...