Syntheses and properties of benzodipyrrinones

✍ Scribed by Stefan E. Boiadjiev; David A. Lightner

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2003
• Tongue: English
• Weight: 55 KB
• Volume: 40
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570400127

✦ Synopsis

Abstract

2,3‐Benzannelated dipyrrinone analogs (1 and 2) of xanthobilirubic acid (3) are prepared by base‐catalyzed condensation of isoindolinone (5) and indolin‐2‐one (6) respectively, with methyl 3‐(2‐formyl‐3,5‐dimethyl‐1__H__‐pyrrol‐4‐yl)propanoate (4). Nuclear Overhauser effect H‐nmr studies indicate that both 1 and 2 adopt preferentially a syn‐Z configuration. The former forms a hydrogen‐bonded homodimer in nonpolar solvents; the latter is intramolecularly hydrogen bonded.