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Synthesis of pyrazoles and oxyquinoxalines from 2,4‐dioxohexenoales
Author(s) -
El Khadem H.,
ElShafei Zaki,
Rateb Latif,
Mokhtar Hassan
Publication year - 1973
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.5570100104
Subject(s) - chemistry , hydrolysis , borohydride , condensation , hydroxymethyl , medicinal chemistry , o phenylenediamine , organic chemistry , sodium borohydride , catalysis , physics , thermodynamics
Condensation of ethyl 2,4‐dioxo‐6‐phenylhex‐5‐enoates (I; R = H, I; R = Me, I, R = Ph) with various hydrazines yielded ethyl 5‐styrylpyrazole‐3‐carboxylates (III), which were hydrolyzed to the acids (IV), and ozonized to 5‐keto pyrazole esters (VI) and acids (VII). Reduction of the 5‐formylpyrazoles (VI; R = II) with borohydride afforded the 5‐hydroxymethyl derivatives (VIII). The same 2,4‐dioxohexenoates (I) when treated with o‐phenylenediamine gave 2‐oxy‐quinoxalines (V; R = H, V; R = Me, V; R = Ph). The uv spectra data of these compounds are given.