The first Bischler–Napieralski cyclization in a room temperature ionic liquid

We have demonstrated the use of the room temperature ionic liquid, 1-butyl-3-methylimidazoliumhexafluorophosphate ([bmim]PF6), as an environmentally benign solvent for the preparation of isoquinoline derivatives through Bischler–Napieralski cyclization under mild conditions with excellent purity and yields. The role of HF as a catalyst in the reaction was also investigated.