The Reaction of 3-Formylchromone with ortho-Substituted Anilines. Preparation of a Tetraaza [14]annulene

✍ Scribed by Ivo Sigg; Georges Haas; Tammo Winkler

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: German
• Weight: 293 KB
• Volume: 65
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19820650128

✦ Synopsis

Abstract

The reactions of 3‐formylchromone (1) with 1, 2‐phenylenediamine, 2‐amino‐diphenylamine and 2‐aminophenol were reinvestigated and shown to yield 1, 8‐dihydro‐6, 13‐di (2‐hydroxybenzoyl)‐dibenzo [b, i]‐l, 4, 8, 11‐tetraazacyclotetradeca‐ 4, 6, 11,13‐tetraene (7), 3‐[2‐(1‐phenyl)benzimidazolyl]chromone (10b) and 3‐(2‐hydroxyphenyl)iminomethylchromone (4), respectively at variance with earlier reports. Compound 4 reacts with ethanol to give 2‐ethoxy‐3‐[(2‐hydroxyphenyl)‐aminomethylidene]chroman‐4‐one (5b). Dehydrogenation of 7 produces 3‐(2‐benz‐imidazolyl)chromone (10a), also at variance with earlier reports. The structures have been elucidated with the aid of NMR. and mass spectra. The reaction mechanism is discussed.