title: Expeditious, four-component synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives catalyzed by trichloroacetic acid or ceric sulfate.
abstract: Two efficient and convenient procedures for the synthesis of 6-amino-3-methyl-1,4-diphenyl-1,4-dihydropyrano[2,3c]pyrazole-5-carbonitrile derivatives based on four-component reaction involving ethyl acetoacetate, phenylhydrazine, malononitrile, and various aromatic aldehydes using trichloroacetic acid or ceric sulfate as heterogeneous catalysts in excellent yields and short reaction times have been described.
authors.affiliation: Department of Chemistry, Firoozabad Branch, Islamic Azad University, P.O. Box 74715-117 Firoozabad, Fars, Iran. zahed.karimi@yahoo.com
authors.forename: Zahed
authors.initials: Z
authors.lastname: Karimi-Jaberi
authors.forename: Mohammad Mehdi Reyazo
authors.initials: MM
authors.lastname: Shams
authors.forename: Baharak
authors.initials: B
authors.lastname: Pooladian