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Synthesis and reaction of 5‐amino‐3‐trifluoromethylisoxazole and ‐pyrazole‐4‐carboxylic acids
Author(s) -
Tanaka Kiyoshi,
Suzuki Takashi,
Maeno Seiji,
Mitsuhashi Keiryo
Publication year - 1986
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.5570230556
Subject(s) - chemistry , cyanoacetic acid , pyrazole , isoxazole , acylation , carboxylate , carboxylic acid , electrophile , decarboxylation , organic chemistry , catalysis
5‐Amino‐3‐trifluoromethylisoxazole‐ and ‐pyrazole‐4‐carboxylic acids were prepared by the reactions ot trifluoroacetonitrile oxide or ‐imines with cyanoacetic acid derivatives, respectively. The behavior of thus obtained aminoazole‐4‐carboxylic acids toward some electrophiles was examined. In acylation with acyl chlorides, the aminoisoxazole‐4‐carboxylate 2a was diacylated to give the (diacylamino)isoxazole‐4‐carboxylate 7 , whereas the analogous aminopyrazole 5a produced the cyclized pyrazolooxazinone 13 . Moreover, carbamoylation of 2a with isocyanates gave the trifluoromethylisoxazolouracils 10 .