Syntheses of oxazolo[4,5-c]pyridine and 6-azaindole

✍ Scribed by Freddy Tjosaas; Ivar Broendbo Kjerstad; Anne Fiksdahl

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2008
• Tongue: English
• Weight: 373 KB
• Volume: 45
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570450240

✦ Synopsis

Abstract

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The preparation of oxazolo[4,5‐c]pyridine and 6‐azaindole from 4‐bromo‐3‐pivaloylaminopyridine (8) is reported. The oxazolopyridine 2‐tert‐butyl‐oxazolo[4,5‐c]pyridine (9) was successfully prepared from 8 in 78% yield by a new base/TBAB promoted non‐catalyzed microwave cyclisation strategy (10 min) or, alternatively, in 54% yield by conventional heating (48 hrs) and CuI catalysis. The 6‐azaindole 2‐phenyl‐1‐(trimethylacetyl)‐6‐azaindole (13) was prepared from 8 in a two step procedure, including a Sonogashira coupling reaction.