Multicomponent One-Pot Synthesis of 3-Tetrazolyl and 3-Imidazo[1,2-a]pyridin Tetrazolo[1,5-a]quinolines

A series of 18 3-tetrazolyl-tetrazolo[1,5- a ]quinolines were synthesized in 21–90% yields via a novel one-pot Ugi-azide/S N Ar/ring–chain azido-tautomerization process. We report also the synthesis of 10 3-imidazo[1,2- a ]pyridin-tetrazolo[1,5- a ]quinolines in 28–94% yields via a novel one-pot Groebke–Blackburn–Bienaymé/S N Ar/ring–chain azido-tautomerization process. Both synthetic strategies involve the use of microwaves or ultrasound, and catalyst-free conditions. Finally, we show the synthesis of the tetrazolo[1,5- a ]quinoline-3-carbaldehyde and tetrazolo[1,5- a ]quinoline-3-dimethyl acetal at room temperature in methanol as solvent.