A compound of the formula (I) ##STR1## where A is an alkylene or alkenylene group, R.sub.1 is an aryl group which may be substituted, R.sub.2 is a hydrogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a halogenated lower alkyl group, a cycloalkyl group, a lower alkoxyalkyl group, a lower alkylthioalkyl group, a phenyl group which may be substituted or an aralkyl group which may be substituted, R.sub.3 is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkenyl group, a lower alkynyl group or a halogenated lower alkyl group, or R.sub.2 and R.sub.3 may be combined to form a group of --(CH.sub.2).sub.n --(n is 3 or 4), or salt thereof, which is useful as a herbicide.
化合物的式子(I)##STR1##其中,A是一个烷基或烯基基团,R.sub.1是一个可能被取代的芳基基团,R.sub.2是一个氢原子,一个低碳烷基团,一个低碳烯基团,一个低碳炔基团,一个卤代低碳烷基团,一个环烷基团,一个低碳烷氧基烷基团,一个低碳
硫代烷基团,一个可能被取代的苯基团或一个可能被取代的芳基烷基团,R.sub.3是一个氢原子,一个卤原子,一个低碳烷基团,一个低碳烯基团,一个低碳炔基团或一个卤代低碳烷基团,或者R.sub.2和R.sub.3可以结合成--(CH.sub.2).sub.n--(n为3或4)的基团,或其盐,可用作
除草剂。