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

A highly efficient unprecedented catalyst-free microwave-assisted procedure for synthesizing benzo[ d ]imidazo[2,1- b ]thiazoles and N -alkylated 2-aminobenzo[ d ]oxazol in green media was developed. The transformation provided rapid access to functionalized benzo[ d ]imidazo[2,1- b ]thiazoles from 2-aminobenzothiazole and N -alkylated 2-aminobenzo[ d ]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.