Facile Method for the Synthesis of Pyrazolo[3,4-b]-pyrido[4,3-d]-pyrimidine-4-ones via a Tandem Aza-Wittig Reaction
作者:Tao Wang、Cai Hua Zheng、Shu Liu、Hong Wu He
DOI:10.1080/00397910902730895
日期:2009.9.8
Abstract Fifteen novel pyrazolo[3,4-b]-pyrido[4,3-d]-pyrimidine-4-ones (7a–o) were designed and have been successfully synthesized via tandemaza-Wittig and annulation reactions of the corresponding iminophosphorances 5, phenylisocyanate, and substituted phenols in 60–77% isolated yields. Their structures were clearly verified by infrared (IR), 1H NMR, electron impact–mass spectrometry (EI-MS), and