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β‐Oxoanilides in heterocyclic synthesis: An expeditious synthesis of new polyfunctionally substituted pyridine and pyrazole derivatives
Author(s) -
Hussein A. M.,
Harb A. A.,
Mousa I. A.
Publication year - 2008
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.5570450641
Subject(s) - chemistry , hydrazine (antidepressant) , acetic anhydride , pyrazole , hydrate , pyridine , yield (engineering) , methylene , derivative (finance) , reagent , organic chemistry , oxime , malononitrile , hydrochloride , medicinal chemistry , hydroxylamine , condensation reaction , catalysis , materials science , chromatography , economics , financial economics , metallurgy
3‐Oxo‐ N ‐{4‐[(pyrimidin‐2‐ylamino)sulfonyl]phenyl}butanamide 3 was condensed with (DMF‐DMA) in refluxing dry dioxane to yield branched structure 4 not its linear isomeric 5 . Compound 4 readily reacted with active methylene to yield compounds 8a‐c, 14, 17 and 20 respectively. Also enaminone 4 reacted with phenyl hydrazine giving 24 and 25 . In contrast, when compound 4 reacted with hydrazine hydrate in the same experimental conditions pyrazole derivative 27 was obtained. Furthermore, condensation of anilide 3 with triethylorthoformate in refluxing acetic anhydride afforded the ethoxy methylene derivative 28 . On the other hand, compound 28 was reacted with active methylene reagents, and hydrazines to afford the products identical in all respects (mp., mixed mp., and spectral data) with those corresponding to compounds 6‐27 respectively. Similarly, compound 3 was reacted with hydrazine hydrate to afford the reaction product 29 . Also, compound 3 reacted with cyanoacetamide in refluxing ethanolic pipridine solution to yield the pyridine derivative 30 . Finally, 3 reacted with hydroxylamine hydrochloride in refluxing ethanol/sodium acetate solution to yield the acyclic oxime derivative 31 .