Compounds of formula I
wherein R1 is 1-2C-alkoxy optionally substituted by flourine, R2 is methyl, 1-methylethyl, 3-7C-cycloalkyl or 3-7Ccycloalkylmethyl and Ar is a pyridyl which is optionally di-halo substituted.
式I中的化合物,其中R1是1-2C-烷氧基,可以选择性地被
氟取代,R2是甲基,1-甲基乙基,3-7C-环烷基或3-7C-环烷基甲基,Ar是一种
吡啶基,可以选择性地被二卤取代。