A compound of formula I: Formula I ** Formula ** in which - X is CH or N； R1 represents -NO2, -N (CH3) 2, or -NCH3 (CH2CH2OH)； and R2 represents hydrogen, methyl, ethyl, n-propyl, isopropyl, tert-butyl, cyano, halogen, methoxy, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, methylsulfonyl, acetyl, or acetylamino； or - X is CH, R1 is hydrogen, and R2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, methylsulfonyl, acetylamino, or methoxycarbonyl； or - X is CH, R1 is cyano, and R2 is ethyl, isopropyl, tert-15-butyl, ethoxy, n-propoxy, isopropoxy, trifluoromethyl, difluoromethoxy, trifluoromethoxy, methylsulfonyl, or acetylamino； or - X is CH, R1 is chloro, and R2 is ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, difluoromethoxy, methylsulfonyl, or acetylamino； or - X is CH, R1 is methoxy or isopropoxyl, and R2 is trifluoromethyl； or - X is CH, R1 is methylsulfonyl or ethylsulfonyl, and R2 is trifluoromethyl, ethyl, isopropyl, tert-butyl, ethoxy, n-propoxy, isopropoxy, or difluoromethoxy； or a salt of such a compound.Un compuesto de fórmula I: Fórmula I **Fórmula** en la cual - X es CH o N； R1 representa -NO2, -N(CH3)2, o -NCH3(CH2CH2OH)； y R2 representa hidrógeno, metilo, etilo, n-propilo, isopropilo, tert-butilo, ciano, halógeno, metoxilo, etoxilo, n-propoxilo, isopropoxilo, trifluorometilo, difluorometoxilo, metilsulfonilo, acetilo, o acetilamino； o - X es CH, R1 es hidrógeno, y R2 es etilo, isopropilo, tert-butilo, etoxilo, n-propoxilo, isopropoxilo, metilsulfonilo, acetilamino, o metoxicarbonilo； o - X es CH, R1 es ciano, y R2 es etilo, isopropilo, tert-15 butilo, etoxilo, n-propoxilo, isopropoxilo, trifluorometilo, difluorometoxilo, trifluorometoxilo, metilsulfonilo, o acetilamino； o - X es CH, R1 es cloro, y R2 es etilo, isopropilo, tert-butilo, etoxilo, n-propoxilo, isopropoxilo, difluorometoxilo, metilsulfonilo, o acetilamino； o - X es CH, R1 es metoxilo o isopropoxilo, y R2 es trifluorometilo； o - X es CH, R1 es
