Herein, we wish to report a new and convenient method for the synthesi of 2-unsubstituted1,3-selenazoles which relies on the fragmentation of novel 2-benzoyl-l,3-selenazoles.6 In addition, a second ap- proach to 2-unsubstituted1,3-selenazoles by cyclization of selenoformamide with u-bromoketones is reported. The cyclization of a-bromoacetophenone (la) with sele- nophenylacetic amide (2a), prepared
2-Acyl-1,3-selenazoles were prepared in two steps from α-bromoketones and seleno amides. The base mediated fragmentation of these compounds afforded 2-unsubstituted 1,3-selenazoles. The reaction of 2-acyl-1,3-selenazoles with hydroxylamine hydrochloride afforded oximes which were transformed into 2-carbamoyl-1,3-selenazoles by a regioselective Beckmann rearrangement.