A compound of the formula:
wherein R is methyl or ethyl, X is hydrogen (provided R is ethyl), lower alkyl, lower alkoxy, lower alkylthio, fluorine, bromine, phenoxy or substituted phenoxy, Xm is methylenedioxy or -CH=CH-CH=CH-, and m is 1, 2 or 3.
式中 R 为甲基或乙基,X 为氢(前提是 R 为乙基)、低级烷基、低级烷氧基、低级烷
硫基、
氟、
溴、苯氧基或取代苯氧基,Xm 为亚甲基二氧基或-CH=CH-CH=CH-,m 为 1、2 或 3。