An ionic liquid as a recyclable medium for the green preparation of α,α′-bis (substituted benzylidene)cycloalkanones catalyzed by FeCl3·6H2O

The utilization of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) as reaction medium, and of iron (III) chloride hexahydrate as a catalyst is described for the efficient preparation of α,α′-bis(substituted benzylidene)cycloalkanones. The preparative process presented here is operationally simple, environmentally benign and has the advantage of enhanced atom utilization. Furthermore, the solvent and the catalyst used can be recovered conveniently and reused efficiently.