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Reaction of acetylenic ketones with hydrazine derivatives. Synthesis of hydroxypyrazoles
Author(s) -
AlHajjar Farouk S.,
Sabri Salim S.
Publication year - 1986
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.5570230317
Subject(s) - chemistry , acetic anhydride , potassium hydroxide , hydrazine (antidepressant) , yield (engineering) , hydrolysis , aryl , organic chemistry , potassium , medicinal chemistry , catalysis , materials science , alkyl , chromatography , metallurgy
Aroylphenylacetylenes Ia‐c react with (‐butyl hydrazinecarboxylate (IIa) and 2‐furylhydrazide (IIb) to give the corresponding hydroxydihydropyrazole derivatives IVa‐f. This cyclic structure is supported by chemical transformations. Thus, when compounds IVa‐c are heated with acetic anhydride, they yield the corresponding 5‐aryl‐1‐( t ‐butoxycarbonyl)‐3‐phenylpyrazoles Va‐c which, upon hydrolysis with methanolic potassium hydroxide, produce the corresponding 5(3)aryl‐3(5)phenylpyrazoles VI. Spectroscopic data also confirm the suggested cyclic structure IV.