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/SNAr/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/SNAr/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.