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Enaminone Incorporating a Dibromobenzofuran Moiety: Versatile Precursor for Novel Azines and Azolotriazines
Author(s) -
Sanad Sherif M. H.,
Mekky Ahmed E. M.
Publication year - 2018
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.3107
Subject(s) - chemistry , moiety , acetonitrile , triazine , combinatorial chemistry , furan , azo coupling , dimethylformamide , chloride , stereochemistry , medicinal chemistry , organic chemistry , solvent
2‐Acetyl‐5,7‐dibromobenzo[ b ]furan ( 1 ) reacted with dimethylformamide‐dimethylacetal to give the corresponding ( E )‐enaminone 3 which coupled with aromatic diazonium chloride to afford the corresponding key intermediates 3‐oxo‐2‐(2‐arylhydrazono)propanals 6a , b . Compounds 6a , b were used to prepare novel 3‐imino‐2,3‐dihydropyridazines 10a , b and 6‐phenylazopyrido[2,3‐ d ]pyrimidin‐4(1 H )‐one derivatives 15a , b through their reaction with acetonitrile derivatives 8a , b and 6‐aminopyrimidin‐4(1 H )‐one 13 , respectively. On the other hand, the enaminone 3 was taken as a synthetic precursor to synthesize novel pyrazolo[5,1‐ c ][1,2,4]triazines 21a – c , [1,2,4]triazolo[3,4‐ c ][1,2,4]triazines 25 and benzimidazo[2,1‐ c ][1,2,4]triazine 29 containing 5,7‐dibromobenzofuran‐2‐oyl moiety via its coupling with the appropriate diazonium salts of a variety of hetero‐armomatic amines in a facile one‐step route.