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Syntheses of oxazolo[4,5‐ c ]pyridine and 6‐azaindole
Author(s) -
Tjosaas Freddy,
Kjerstad Ivar Broendbo,
Fiksdahl Anne
Publication year - 2008
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570450240
Subject(s) - chemistry , pyridine , sonogashira coupling , yield (engineering) , catalysis , base (topology) , medicinal chemistry , organic chemistry , combinatorial chemistry , palladium , mathematical analysis , materials science , mathematics , metallurgy
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.