GR77606

Compounds of the formula wherein R1 is cycloalkyl of 3 to 10 carbon atoms; phenyl; mono- or poly-substituted phenyl, where the substituents are halogen, lower alkyl, lower alkoxy, lower alkenyl, lower alkinyl, lower alkinyloxy, lower cycloalkyl, acyl, acyloxy, lower alkoxycarbonyl, hydroxy-lower alkyl, lower alkoxy-lower alkyl or the ring-forming groups (-CH=CH-)2 or -O-CH2-O- attached to vicinal carbon atoms of the phenyl ring; aryloxy-lower alkyl; (mono- or poly-substituted aryl)-oxy-lower alkyl, where the substituents are halogen, lower alkyl, lower alkoxy, lower alkenyl, lower alkinyl, lower alkinyloxy, lower cycloalkyl, acyl, acyloxy, lower alkoxycarbonyl, hydroxy-lower alkyl, lower alkoxy-lower alkyl or the ring-forming groups (-CH=CH-)2 or -O-CH2-O- attached to vicinal carbon atoms of the phenyl ring; R2 is hydrogen, halogen, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms or the ring-forming group (-CH=CH)2 or -(CH2)n-, where n is an integer from 3 to 5, attached to vicinal carbon atoms of the phenyl ring; and R3 is straight or branched alkyl of 1 to 10 carbon atoms; and non-toxic, pharmacologically acceptable acid addition salts thereof. The compounds as well as their salts are useful for the treatment of tachycardia, hypertension and coronary diseases.