A new method for the synthesis of substituted indeno[1,2-b]thiophene with subsequent ring expansion to form substituted thieno[3,2-c]quinoline

✍ Scribed by Lyle W. Castle; Tarek Abou Elmaaty

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2006
• Tongue: English
• Weight: 204 KB
• Volume: 43
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570430316

✦ Synopsis

Abstract

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2‐Phenacylindan‐1,3‐dione (3) was treated with Lawesson's reagent (2,4‐bis(4‐methoxyphenyl)‐1,3‐dithia‐2,4‐diphosphetane‐2,4‐disulfide) to form 2‐phenyl‐4__H__‐indeno[1,2‐b]thiophene‐4‐one (4). Compound 4 was subsequently reacted with hydroxyl amine to form the oxime (5), which, upon treatment with polyphosphoric acid, underwent ring expansion (Beckmann rearrangement) to give 2‐phenylthieno[3,2‐c]quinoline‐4(5__H__)one.