The new compounds of the general Formula I ##STR1## (wherein R.sub.1 stands for C.sub.1-4 alkyl or aralkyl; andR.sub.2 represents hydroxy; orR.sub.1 and R.sub.2 together form a valency bond;R.sub.3 is hydrogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, phenyl, amino, alkylthio or a group of the Formula --NR.sub.7 R.sub.8 in which R.sub.7 and R.sub.8 may be the same or different and stand for hydrogen, C.sub.1-4 alkyl, phenyl-C.sub.1-4 alkyl, hydroxy-C.sub.1-4 alkyl or di-(C.sub.1-4 alkyl)-amino-C.sub.1-4 alkyl or together with the nitrogen atom they are attached to form a 6-membered heterocyclic ring which may optionally contain a further nitrogen, oxygen or sulfur atom; orR.sub.2 and R.sub.3 together form an oxo (.dbd.O) or thixo (.dbd.S) group;R.sub.4 represents hydrogen, C.sub.1-4 alkyl or phenyl which may optionally bear one or two halogen or nitro substituent(s);Z is a group of the Formula (a) or (b) ##STR2## A.sup.- represents an anion) and isomers thereof possess useful local anaesthetic, antidepressant, tranquillo-sedative and smooth muscle relaxant properties accompanied by a weaker analgesic effect and are useful in therapy.