Abstract: Compounds of the formula ##STR1## where R.sub.1, R.sub.2 and R.sub.3 are each independently of the others hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, halogen or C.sub.1 -C.sub.4 alkanoylamino,R is hydrogen or unsubstituted or C.sub.1 -C.sub.4 alkoxy substituted C.sub.1 -C.sub.12 alkyl or an --(alk)--NA.sup..sym. X.sup..crclbar. radical or,R forms together with an R.sub.1 in the ortho-position relative to the amino group a partially hydrogenated, substituted or unsubstituted 5- to 7-membered heterocyclic ring which may contain additional N, S or O atoms as ring members, (alk) is a substituted or unsubstituted C.sub.1 -C.sub.6 alkylene radical,--NA.sup..sym. is the radical of an amino compound of formula ##STR2## where R.sub.4, R.sub.5 and R.sub.6 are each independently of the others substituted or unsubstituted C.sub.1 -C.sub.6 alkyl, substituted or unsubstituted C.sub.7 -C.sub.12 aralkyl or substituted or unsubstituted aryl, R.sub.8 and R.sub.