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A facile synthesis of pyrazole‐5‐sulfonamide derivatives
Author(s) -
Yamamoto Susumu,
Sato Toshiaki,
Morimoto Katsushi,
Makino Kenzi
Publication year - 1991
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570280808
Subject(s) - chemistry , pyrazole , lithium diisopropylamide , sulfonamide , lithium (medication) , butyllithium , sulfur , organic chemistry , medicinal chemistry , ion , medicine , deprotonation , endocrinology
The reaction of the 5‐unsubstituted pyrazoles 2a‐k with lithium diisopropylamide or n ‐butyllithium gave intermediary 5‐lithiopyrazoles, whose reaction with sulfur dioxide afforded the lithium pyrazole‐5‐sulfinates 3a‐k . Subsequent reaction of 3a‐k with N ‐chlorosuccinimide followed by ammonolysis provided the pyrazole‐5‐sulfonamides 5a‐k .