Regioselective Synthesis of 1,3,5-Tri- and 1,3,4,5-Tetrasubstituted Pyrazoles from N-Arylhydrazones and Nitroolefins
摘要:
[GRAPHICS]Two general protocols are developed for the regioselective synthesis of 1,3,5-tri- and 1,3,4,5-tetrasubstituted pyrazoles by the reaction of electron-deficient N-arylhydrazones with nitroolefins. Studies on the stereochemistry of the key pyrazolidine intermediate suggest a stepwise cycloaddition mechanism.
Synthesis of 1,3,4-Trisubstituted and 1,3,4,5-Tetrasubstituted Pyrazoles
申请人:Deng Xiaohu
公开号:US20090093637A1
公开(公告)日:2009-04-09
This invention concerns the synthesis of highly substituted pyrazoles, which are structural components of pharmacological compounds, through reaction of hydrazones with nitroolefins.