Use of SO3H-functionalized halogenfree ionic liquid ([MIM(CH2)4SO3H] [HSO4]) as efficient promoter for the synthesis of structurally diverse spiroheterocycles

Structurally diverse spiroheterocycles with fused systems incorporating medicinally privileged systems have been synthesized by an efficient and convenient synthetic method involving four component domino reaction of 2-aminobenzothiazoles with isatin and cyclic β-diketones using SO3H-functionlized halogenfree ionic liquid ([MIM(CH2)4SO3H][HSO4]) in aqueous medium.