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A Concise One‐Pot Synthesis of 3,4‐Diaryl‐1 H ‐pyrazoles from Natural Isoflavones and Hydrazine Hydrate
Author(s) -
Zhang ZunTing,
Tan DaJin,
Xue Dong
Publication year - 2007
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200790217
Subject(s) - chemistry , hydrate , hydrazine (antidepressant) , isoflavones , phenol , organic chemistry , reaction conditions , aromatization , pyrazole , medicinal chemistry , combinatorial chemistry , chromatography , catalysis , biochemistry
An efficient protocol has been developed for the preparation of a series of new 3,4‐diaryl‐1 H ‐pyrazoles, potential pharmacological and agricultural targets, by the reaction of hydrazine hydrate with different natural isoflavones or their derivatives. The target compounds were obtained in good‐to‐excellent yields (80–95%; Table 2 ) under fairly mild reaction conditions (80°) tolerating various functional groups. The new compounds were fully characterized, and the single‐crystal X‐ray structures of 3,5‐diethoxy‐2‐[4‐(4‐ethoxyphenyl)‐1 H ‐pyrazol‐3‐yl]phenol ( 26 ) and of the peracetylated compound 2‐{1‐acetyl‐4‐[4‐acetoxy‐3‐(diacetylamino)phenyl]‐1 H ‐pyrazol‐3‐yl}‐5‐acetoxyphenyl acetate ( 35 ) were solved ( Figure ).