Amalgam (Na.Hg) reduction of some 4-Substituted-2-amino-3,5-dicyano-6-methoxypyridines. New evidence regarding the oxidation step in their synthesis

✍ Scribed by LuÍS Fuentes; Ma Jesús Lorenzo; César Márquez; Mikhail Galakhov

• Book ID: 102341309
• Publisher: Journal of Heterocyclic Chemistry
• Year: 1999
• Tongue: English
• Weight: 243 KB
• Volume: 36
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570360225

✦ Synopsis

Abstract

The amalgam (Na.Hg) reduction of some 4‐substituted‐2‐amino‐3,5‐dicyano‐6‐methoxypyridines 3 results in the formation, in high yields of 3,4‐dihydropyridines 2. Highfield ^1^H and ^13^C nmr studies provide unambiguous support for the structures proposed. The synthesis of C‐4 deuterium labeled dihydropyridine 2c‐D, by this procedure, let us understand the role played by this dihydropyridines as intermediates in the necessary oxidation path into the synthesis of pyridines 3 from malononitrile and benzylidenemalononitriles 1 in methanol/sodium methoxide.