A facile and efficient method for the selective deacylation of N-arylacetamides and 2-chloro-Narylacetamides catalyzed by SOCl₂

Thionyl chloride efficiently and selectively promoted the deacylation of N-arylacetamides and 2-chloro-N-arylacetamides, under anhydrous conditions, without effecting the ester group, aminosulfonyl group, or benzyloxyamide group. This method, which has been successfully applied to a variety of substrates including different N-arylacetamides and 2-chloro-N-arylacetamides, has the attractive advantages of inexpensive reagents, satisfactory selectivity, excellent yields, short reaction time, and convenient workup. This new method can probably be used to selectively deacylate between aromatic amides and alkyl amides.