A new dimerization reaction producing 2-amino-9-oxopyrrolo-[2,1-b]quinazoline-1-carbonitriles and analogous pyrrolo-[1,2-a]thieno[3,2-d] pyrimidinecar bonitriles

✍ Scribed by Michael Gütschow; James C. Powers

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2001
• Tongue: English
• Weight: 68 KB
• Volume: 38
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570380217

✦ Synopsis

Abstract

A series of 2‐alkylthio‐4‐oxo‐3‐quinazolineacetonitriles 4 and 2‐alkylthio‐4‐oxothieno[3,2‐d]pyrimidine‐3‐acetonitriles 8 was prepared. Upon treatment with sodium hydride, compounds 4 and 8 react to give 2‐amino‐4,9‐dihydro‐9‐oxopyrrolo[2,1‐b]quinazoline‐1‐carbonitriles 9 and 6‐amino‐4,9‐dihydro‐9‐oxopyrrolo[1,2‐a]thieno[3,2‐d]pyrimidine‐7‐carbonitriles 10, respectively. The transformation of compounds 4 and 8 to the tricyclic aminonitriles 9 and 10 involves a dimerization step followed by a pyrrole cyclization. The tert‐butyl ester derivatives 4d and 8d upon treatment with sodium hydride underwent a Thorpe‐Ziegler cyclization to provide enaminoesters of fused 1,3‐thiazines (16 and 17, respectively) as major products.