Substituent-Oriented Synthesis of Substituted Pyrazoles/Chromeno[3,2-<i>c</i>]pyrazoles via Sequential Reactions of Chromones/3-Chlorochromones and Tosylhydrazones
作者:Tianzi Dai、Qunyi Li、Xiaofei Zhang、Chunhao Yang
DOI:10.1021/acs.joc.9b00282
日期:2019.5.3
A facile and efficient synthetic strategy for the chemoselective synthesis of monocyclic/tricyclic-fused pyrazoles was developed, and it was oriented by different 3-position substituents (H or Cl) on the chromones. The reaction proceeded in a one-pot sequential way with a broad substrate scope and moderate to excellent yields.
Cr-MCM-41 zeolite supported on silica gel can be used as an effective and mild oxidizing agent for the direct conversion of oximes and tosylhydrazones to carbonyl compounds under microwave irradiation in good yield. The procedure is applicable to the variety of oximes and tosylhydrazones and the zeolite can be recycled.