Regiospecific synthesis of 3H-pyrido[2,3-b][1,4]diazepin-4(5H)-ones via haloform reaction with the isolation of N3-[3-oxo-4,4,4-trichloroalk-1-en-1-yl]-2,3-diaminopyridine intermediates

✍ Scribed by Helio G. Bonacorso; Rogério V. Lourega; Liliane M. F. Porte; Everton D. Deon; Nilo Zanatta; Alex F. C. Flores; Marcos A. P. Martins

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2009
• Tongue: English
• Weight: 206 KB
• Volume: 46
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.89

✦ Synopsis

Abstract

magnified image

The synthesis of a novel series of analogous intermediates N^3^‐[1‐alkyl(aryl/heteroaryl)‐3‐oxo‐4,4,4‐trichloroalk‐1‐en‐1‐yl]‐2,3‐diaminopyridines and N^2^‐(methanesulfonyl) [Cl~3~CC(O)CHCRNH(C~5~H~3~N)NHY], where R = H, Me, C~6~H~5~, 4‐FC~6~H~4~, 4‐ClC~6~H~4~, 4‐BrC~6~H~4~, 4‐CH~3~C~6~H~4~, 4‐OCH~3~C~6~H~4~, 4,4′‐biphenyl, 1‐naphthyl, 2‐thienyl, 2‐furyl, and Y = H, SO~2~Me, is reported. A new corresponding series of 2‐aryl/heteroaryl‐3__H__‐pyrido[2,3‐b][1,4]diazepin‐4(5__H__)‐ones obtained from intramolecular cyclization reaction of the first series of trichloroacetyl enamines or from the direct cyclocondensation reaction of 4‐methoxy‐1,1,1‐trichloalk‐3‐en‐2‐ones with 2,3‐diaminopyridine, under mild conditions, is also demonstrated. J. Heterocyclic Chem., (2009).