A compound of the formula ##SPC1##WhereinR.sub.1 is selected from the group consisting of phenyl and straight or branched chain alkyl;R.sub.2 is selected from the group consisting of straight or branched chain lower alkyl, straight or branched chain lower alkenyl, lower alkynyl, lower alkoxymethyl, lower alkylthiomethyl and benzyl;X is a same or different substituent which is selected from the group consisting of straight or branched chain alkyl, lower alkoxycarbonyl, phenyl, substituted phenyl having at least one substituent selected from the group consisting of halogen, methyl and methoxy, styryl, furyl, thienyl and --(CH.sub.2)m-- in which m is an integer from 1 to 6;n is 0 or an integer from 1 to 6;Z is a substituent selected from the group consisting of R-A- and T in which R is selected from the group consisting of lower alkyl, phenyl, substituted phenyl having at least one substituent selected from the group consisting of halogen, methyl, methoxy and nitro, benzyl, phenoxymethyl and phenoxymethyl substituted with at least one halogen;A is selected from the group consisting of carbonyl and sulfonyl;T is selected from the group consisting of lower alkyl and benzyl;Is useful as herbicide.