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Syntheses with nitriles. 62 . 3,5‐Dicyanopyridine derivatives by vilsmeier formylation of malononitrile and tetracyanopropenides
Author(s) -
Mittelbach Martin,
Junek Hans
Publication year - 1982
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.5570190508
Subject(s) - malononitrile , chemistry , formylation , dimethylformamide , pyridine , methylene , cyanoacetamide , organic chemistry , alkaline hydrolysis , hydrolysis , phosphorus , medicinal chemistry , catalysis , solvent
Reaction of malononitrile with dimethylformamide and phosphorus oxychloride gave (dimethylamino‐methylene)malononitrile ( 1 ), 4‐chloro‐7‐methyl‐5,7‐diaza‐1,3,5‐octatriene‐1,1,3‐tricarbonitrile ( 3a ) and the pyridine 2 . Compounds 3a and 3b as well as the triaza‐derivative 3c may also be obtained by treatment of tetracyanopropenides 4a‐c with dimethylformamide and phosphorus oxychloride. Ring closures were achieved by heating 3 under alkaline or acidic conditions. Substitution of chlorine in 3a with aromatic amines provided 1‐aryl‐1,2‐dihydro‐2‐imino‐3,5‐pyridinedicarbonitriles 7 . Hydrolysis of 7 gave the 2‐oxo‐derivatives 8 .