Premium
Studies with enaminones: synthesis of new coumarin‐3‐yl azoles, coumarin‐3‐yl azines, coumarin‐3‐yl azoloazines, coumarin‐3‐yl pyrone and coumarin‐2‐yl benzo[ b ]Furans
Author(s) -
ElTaweel Fathy Mohamed Abel Aziz,
Elnagdi Mohamed Hilmy
Publication year - 2001
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.5570380428
Subject(s) - chemistry , coumarin , yield (engineering) , pyrone , acetic anhydride , pyrimidine , medicinal chemistry , acetic acid , pyridine , organic chemistry , stereochemistry , materials science , metallurgy , catalysis
3‐Acetylcoumarine was condensed with dimethylformamide dimethylacetal (DMFDMA) to yield the enaminone, which reacts readily with hydroxylamine and with hydrazines to yield coumarin‐3‐ylisoxazoles and coumarin‐3‐ylpyrazoles respectively. Reaction of the enaminone with benzamidine hydrochloride and 3‐amino‐1,2,4‐1 H ‐triazole affords the pyrimidine and triazolo[3,4‐ b ]pyrimidine. The enaminone reacts with hippuric acid and with the dithiocarboxylic acid to yield pyranones. The reaction of the enaminone with 3‐amino‐1 H ‐1,2,4‐triazole gives the triazolo[3,4‐ b ]pyrimidine. The enaminone underwent self dimerization on reflux in acetic acid ammonium acetate to yield the coumarinyl pyridines and reacted with ketone under the same conditions to yield the pyridine. The reaction of the enaminone with 1,4‐benzoquinone and 1,4‐naphthoquinone gives benzofuryl coumarine derivatives.