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Free‐radical reactions of diazonium salts with α,β‐unsaturated carbonyl compounds. A new synthesis of 1,4‐diarylpyrazole derivatives
Author(s) -
Citterio Attilio,
Ramperti Massimo,
Vismara Elena
Publication year - 1981
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.5570180426
Subject(s) - chemistry , salt (chemistry) , diazonium compounds , organic chemistry , decomposition , catalysis , pyrazole , radical , ferrous , metal
Free‐radical decomposition of diazonium salts catalyzed by titanous or titanous and ferrous salts in the presence of β‐substituted α,β‐unsaturated carbonyl compounds leads to 1,4‐diarylpyrazole derivatives. The reaction occurs via an intermediate azo compound ( 1 ), which can be reduced by the metal salt or can be isolated and hydrogenated to pyrazole derivatives.