On water catalyst-free synthesis of benzo[]imidazo[2,1-] thiazoles and novel -alkylated 2-aminobenzo[]oxazoles under microwave irradiation.

A highly efficient unprecedented catalyst-free microwave-assisted procedure for synthesizing benzo[]imidazo[2,1-]thiazoles and -alkylated 2-aminobenzo[]oxazol in green media was developed. The transformation provided rapid access to functionalized benzo[]imidazo[2,1-]thiazoles from 2-aminobenzothiazole and -alkylated 2-aminobenzo[]oxazole from 2-aminobenzoxazole scaffolds under mild transition-metal-free conditions. This synthetic manipulation is expected to greatly expand the repertoire of reaction types in heterocyclic chemistry and pave the way for new syntheses of bioactive compounds.