title: Rapid and efficient ultrasound-assisted method for the combinatorial synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole] derivatives.
abstract: An efficient one-pot synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole] derivatives by four-component reaction of hydrazine, β-keto ester, isatin, and malononitrile or ethyl cyanoacetate catalyzed by piperidine under ultrasound irradiation is described. This synthesis was confirmed to follow the group-assistant-purification chemistry (GAP) chemistry process, which can avoid traditional chromatography and recrystallization purifications.
authors.affiliation: Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zou
authors.forename: Yu
authors.initials: Y
authors.lastname: Hu
authors.forename: Hai
authors.initials: H
authors.lastname: Liu
authors.forename: Daqing
authors.initials: D
authors.lastname: Shi
mesh_terms: D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013016:Sound; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013997:Time Factors
chemical_list: D007211:Indoles; D011720:Pyrazoles; D013141:Spiro Compounds