Facile ZrCl₄ promoted four-component coupling one-pot synthesis of polyhydroquinoline derivatives through unsymmetric Hantzsch reaction

1578-1582ZrCl₄ catalyzed efficient unsymmetric Hantzsch reaction via four-component coupling reaction of aldehydes, dimedone, ethyl acetoacetate and ammonium acetate at ambient temperature is described as the preparation of polyhydroquinoline derivatives. The process presented here is an operationally simple, economic, environmentally benign and provides excellent yield. Furthermore, the catalyst can be recovered conveniently and reused efficiently