title: Rapid and efficient one-pot synthesis of spiro[indoline-3,4'-pyrano[2, 3-c]pyrazole] derivatives catalyzed by l-proline under ultrasound irradiation.
abstract: A rapid and efficient ultrasound-promoted one-pot synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole] derivatives is described here. The reaction of substituted phenylhydrazine and dialkyl acetylenedicarboxylate with substituted isatin and malononitrile is catalyzed by l-proline to give good-to-excellent yields in water/ethanol (v/v, 1:1) at room temperature.
authors.affiliation: College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, PR China.
authors.forename: Wang
authors.initials: W
authors.lastname: Liju
authors.affiliation: College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, PR China. Electronic address: ablajan209@hotmail.com.
authors.forename: Keyume
authors.initials: K
authors.lastname: Ablajan
authors.affiliation: College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 830046, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Jun
keywords: Multi-component reaction; One-pot synthesis; Spiropyranopyrazoles; Ultrasound irradiation