Synthesis of 1-(2-benzofurancarbonyl)azulenes using 1-(bromoacetyl)azulenes as new building blocks

✍ Scribed by Satoko Yamashiro; Kimiaki Imafuku

• Book ID: 102338946
• Publisher: Journal of Heterocyclic Chemistry
• Year: 2002
• Tongue: English
• Weight: 152 KB
• Volume: 39
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570390411

✦ Synopsis

Abstract

1‐Acetylazulene (1) was treated with trimethylphenylammonium tribromide in refluxing chloroform to afford 1‐acetyl‐3‐bromoazulene (3) and 3‐bromo‐1‐(bromoacetyl)azulene (4). In a similar manner, 3‐methyl‐, 3‐ethyl‐, 3‐propyl‐, and 3‐methoxycarbonyl‐substituted 1‐acetylazulenes 2a‐d gave the corresponding 3‐substituted 1‐(bromoacetyl)azulenes 5a‐d as major products and 1‐(dibromoacetyl)azulenes 6a‐d as minor ones. The 1‐(bromoacetyl)azulenes 5a‐d are useful as new building blocks. Compounds 5a‐d reacted with salicylaldehydes 9a‐g to yield twenty‐eight cyclized products, 1‐(2‐benzofurancarbonyl)azu‐lenes 11aa‐dg, via 1‐phenoxyacetylazulenes 10aa‐dg.