Use of 3-aryl substituted 5-alkyl-isoxazle-4-carboyxlic acid derivative for preventing endoparasite, new 3-aryl substituted 5-alkyl-isoxazole-4-carboxylic acid derivative and its preparation

PURPOSE: To obtain 3-aryl substituted 5-alkyl-isoxazole-4-carboxylic acid derivatives containing a new compound used to prevent medical and veterinary endoparasites. CONSTITUTION: Compounds of formula I, e.g. N-octadecyl-3-(2,6-dichlorophenyl)-5- ethyl-isoxazole-4-carboxamide, are obtained by allowing compounds of formula II (Y is a suitable free radical) to react with a compound shown by the formula R 2 -X-H. In formula I, R 1 is an alkyl or a halogenoalkyl; R 2 is a cycloalkylalkyl, an arylkyl, a heteroarylalkyl, an aryl, a heteroaryl, a substituted 1-20C alkyl, a 2-18C alkenyl or a cycloalkyl; X is O, S, N, H-NH or, N-R 3 (R 3 is H, a substituted 1-20C alkyl, a 2-18C alkenyl or a 1-6C halogenoalkyl); R 4 is H, a halogen, an alkyl or a halogenoalkyl. COPYRIGHT: (C)1994,JPO