Abstract: This invention relates to compounds having the formula: ##STR1## in which: Ar represents a phenyl, pyridyl, isoxazolyl, oxazolyl or pyrazolyl radical which may be mono- or poly-substituted with halogen atoms, hydroxy radicals, C.sub.1-4 alkyl radicals or C.sub.1-4 alkoxy radicals,R represents a hydrogen atom, a C.sub.1-4 alkyl radical, a C.sub.2-4 alkenyl radical, a C.sub.2-4 alkynyl radical, a hydroxy-C.sub.1-4 alkyl radical, a mono- or di-C.sub.1-4 alkyl-amino-C.sub.1-4 alkyl radical or a phenyl radical,R.sub.1 and R.sub.2, when taken separately, represent each a hydrogen atom or a C.sub.1-4 alkyl radical or, when taken together with the nitrogen atom to which they are attached, form a saturated or unsaturated 5- or 6-membered heterocyclic radical which may optionally contain, as second heteroatom, an oxygen or nitrogen atom and which may carry a C.sub.1-4 alkyl radical; and their therapeutically acceptable acid addition salts.

Abstract: The present invention relates to compounds having the general formula: ##STR1## in which R.sub.1 and R.sub.2, which may be the same or different, represent each a hydrogen atom, a C.sub.1 -C.sub.6 alkyl radical or a C.sub.3 -C.sub.6 cycloalkyl radical; R.sub.3 represents a hydrogen atom or a C.sub.1 -C.sub.4 alkyl radical; R.sub.4 and R.sub.5, which may be the same or different, represent a hydrogen atom a C.sub.1 -C.sub.6 alkyl radical or, together with the nitrogen atom to which they are attached, form a pyrrolidino, piperidino, morpholino or piperazinyl radical optionally substituted with a C.sub.1 -C.sub.4 alkyl radical, or a 4-hydroxypiperidino radical, and their pharmaceutically acceptable acid addition salts.Said compounds are therapeutically useful for the control of the cardio-vascular system and of the blood pressure.