2'-Phenylhydrazino-2-cyanoacrylic acid esters and herbicides containing these compounds

Methyl 2'-(2,4,6-trichlorophenyl)-hydrazino-2-cyanoacrylate.

A process for combating unwanted plants, wherein the plants or the soil are treated with a 2'-phenylhydrazino-2-cyanoacrylic acid ester of the formula ##STR6## where R.sup.1 is methyl, trifluoromethyl, chlorine or bromine, R.sup.2 is chlorine, bromine, iodine or methylsulfonyl, R.sup.3 is hydrogen, chlorine or bromine, or methoxy in the 5-position, in which case R.sup.1 and R.sup.2 are chlorine, or R.sup.3 is chlorine in the 3-position, in which case R.sup.2 is hydrogen, and R.sup.4 is alkyl of 1 to 3 carbon atoms, allyl or propargyl.

A herbicidal composition comprising a carrier or diluent and a herbicidally effective amount of a compound of the formula I ##STR7## where R.sup.1 is methyl, trifluoromethyl, chlorine or bromine, R.sup.2 is chlorine, bromine, iodine or methylsulfonyl, R.sup.3 is hydrogen, chlorine or bromine, or methoxy in the 5-position, in which case R.sup.1 and R.sup.2 are chlorine, or R.sup.3 is chlorine in the 3-position, in which case R.sup.2 is hydrogen, and R.sup.4 is alkyl of 1 to 3 carbon atoms.