A compound of the formula I:
wherein X is an oxygen atom or a sulfur atom, Y is a hydrogen atom or a fluorine atom, Z is an oxygen atom, a methylene group or a group of the formula: N-Rs (in which Rs is a hydrogen atom, a C1-C6 alkyl group, a C3-C7 alkenyl group, a C3-C7 alkynyl group, a halo(C2-C6)alkyl group or a C1-C6 alkoxycarbonylmethyl group), R, is a hydrogen atom, a C1-C6 alkyl group, a C3-C7 alkenyl group, a C3-C7 alkynyl group, a halo(C alkyl group, a halo(C3-C7)alkenyl group, a cyano(C1-C6)alkyl group, a C1-C6 alkoxy(C1-C6)alkyl group or a C1-C6 alkoxycarbonylmethyl group, R2 is a hydrogen atom or a C1-C6 alkyl group; R3 and R4 are, the same or different, each a hydrogen atom or a C1-C6 alkyl group; n is an integer of 0 or 1, which is useful as a herbicide.
                            式 I 的化合物
其中 X 是氧原子或
硫原子,Y 是氢原子或
氟原子,Z 是氧原子、亚甲基或式中的基团:N-Rs(其中 Rs 是氢原子、C1-C6 烷基、C3-C7 烯基、C3-C7 炔基、卤代(C2-C6)烷基或 C1-C6 烷氧羰基甲基),R, 是氢原子、C1-C6 烷基、C3-C7 烯基、C3-C7 炔基、卤代(C2-C6)烷基或 C1-C6 烷氧羰基甲基、C3-C7炔基、卤代(C-烷基)、卤代(C3-C7)烯基、
氰基(C1-C6)烷基、C1-C6烷氧基(C1-C6)烷基或C1-C6烷氧基羰基甲基,R2是氢原子或C1-C6烷基;R3 和 R4 相同或不同,各自为氢原子或 C1-C6 烷基;n 为 0 或 1 的整数,可用作
除草剂。