Preparation of substituted 1,3-dihydro-2H-imidazo[4,5-c]pyridin-2-ones

✍ Scribed by Jan M. Bakke; Hanna S. H. Gautun; Harald Svensen

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2003
• Tongue: English
• Weight: 66 KB
• Volume: 40
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570400405

✦ Synopsis

Abstract

A new synthetic route to 6‐substituted‐imidazo[4,5‐c]pyridin‐2‐ons from 4‐aminopyridine has been investigated. 4‐Aminopyridine protected as alkyl carbamates were nitrated with dinitrogen pentoxide to the corresponding methyl, i‐propyl and t‐butyl 3‐nitropyridin‐4‐yl carbamates (5a‐c) in 51‐63 % yields. Attempts to substitute these in the 6‐position by the ONSH and the VNS techniques succeeded with butyl‐amine and the t‐butyl carbamate 9. From the methyl or t‐butyl 3‐nitropyridin‐4‐yl carbamates 5a, 5c 1,3‐dihydro‐2__H__‐imidazo[4,5‐c]pyridin‐2‐one (1) was formed in 73 and 39 % yields, respectively. t‐Butyl 6‐N‐butylamin‐3‐aminopyridin‐4‐yl carbamate (6) gave 6‐butylamino‐1,3‐dihydro‐2__H__‐imidazo[4,5‐c]‐pyridin‐2‐one (7) in 53 % yield.