Compound of the formula, ##STR1## wherein X is a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxyl group, R.sup.1 is a methyl group or an ethyl group, R.sup.2 is a hydrogen atom, a lower alkyl group or an allyl group, and each of R.sup.3 and R.sup.4, independently, is a hydrogen atom, a methyl group or an ethyl group; provided that R.sup.1, R.sup.3 and R.sup.4 are not methyl groups simultaneously when both X and R.sup.2 are hydrogen atoms, and compositions containing these compounds exhibit herbicidal activity.