Inhibiting adrenergic .beta.-receptors with piperidinopropyl derivatives

A piperidinopropyl derivative of the formula ##STR12## in which R.sub.1 and R.sub.2 each independently is hydrogen or a lower alkyl radical, or together are a C.sub.2-4 -alkylene radical,

• R.sub.3 is hydrogen, hydroxy, or lower alkanoyloxy,
• R.sub.4 is hydrogen or formyl,
• A is (a) --X.sub.1 .dbd.Y.sub.1 in which
• (i) X.sub.1 and Y.sub.1 each independently is a nitrogen atom or --C(R.sub.6).dbd., in which
• (A)R.sub.6 is hydrogen, a lower alkyl radical optionally substituted by hydroxy or lower alkanoyloxy, a carboxyl radical or an alkoxycarbonyl radical, or
• (b)--X.sub.2 --Y.sub.2 in which
• (i) X.sub.2 is --CH.sub.2 -- or --N(R.sub.7)--, in which (A)R.sub.7 is hydrogen or lower alkyl, and
• (ii) Y.sub.2 is --CH.sub.2 -- or --C(.dbd.Z)--, in which (A)Z is oxygen or sulfur, or
• (c)--CR.sub.8 .dbd.CR.sub.9 -- in which
• (i) R.sub.8 and R.sub.9 together are a --CH.dbd.CH--CH.dbd.CH--bridge, with the proviso that when present, it is Y.sub.1 or Y.sub.2 which is connected to N--R.sub.4, and
• B is a pyridyl, primidyl, benzimidazolinonyl, benzimidazolinyl, benztriazolyl, indazolyl, benzodioxolanyl or carbazolyl radical or, if A is --X.sub.2 --Y.sub.2 -- or --CR.sub.8 .dbd.CR.sub.9, may also be a phenyl radical, either of which is optionally substituted by halogen, hydroxyl, lower alkyl, hydroxy-lower alkyl, carboxamido-lower alkyl, lower alkoxy, amino, carboxamido, lower alkyl-carbonylamino, lower alkanoyloxy or lower alkylsulphonylamino,
• or a pharmacologically acceptable salt thereof.