Herbicidal and plant growth-regulating compounds of the formula ##STR1## in which R.sup.1 represents hydrogen or nitro,R.sup.2 represents hydrogen, alkyl or a radical ##STR2## A.sup.1 and A.sup.2 independently of each other each represent a divalent alkylene radical,Y represents halogen, hydroxyl, optionally substituted alkoxy, optionally substituted aryloxy or a radical ##STR3## R.sup.3 represents hydrogen, alkyl, alkoxy, amino, alkylamino, dialkylamino or in each case optionally substituted aryl, aryloxy or arylamino,Ar represents in each case optionally substituted phenyl or pyridyl andn represents a number 1, 2, 3 or 4.