| Abstract: | 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 . |
