Modification of the Gewald methodology for the synthesis of 3-amino-2-(1H-1,2,3-benzotriazol-1-yl) substituted benzofurans, benzothiophenes and 1H-indoles

Treatment of 1- chloromethylbenzotriazole ( 4) with salicylonitrile ( 5a), thiosalicylonitrile ( 5b), ethyl N-( 2- cyanophenyl) carbamate ( 5c), and N-( 2- cyanophenyl) methane- sulfonamide ( 5d) provided the corresponding intermediates 3. Cyclization of compounds 3a- 3c with LDA gave 2( 1H- benzo[ d][ 1,2,3] triazol- 1- yl) benzofuran- 3- amine ( 2a), 2-( 1H- benzo[ d][ 1,2,3] triazol- 1yl) benzo[ b] thiophen- 3- amine ( 2b), and ethyl 3- amino- 2-( 1H- benzo[ d][ 1,2,3] triazol- 1- yl)- 1H-indole1- carboxylate ( 2c), respectively. Attempts to accomplish elimination of the benzotriazole nitrogen under both thermal and photolytic conditions failed.