[Potential cardiotonic agents. 8. 2-acyloxyalkylamino-, 2-acyloxyalkoxy-, and 2-acylaminoalkylamino-3-cyan-5-(pyrid-4-yl) pyridine].

By acylation of our previously described cardiotonic active 2-hydroxyalkylamino, 2-hydroxyalkoxy, 2-aminoalkyl-amino and 2-piperazino substituted 3-cyano-5-(4-pyridinyl) pyridines with acetic anhydride, propionic anhydride or aroyl and heteroaroyl chlorides, respectively, the corresponding in position 2 O- or N-acylated 3-cyano-5-(4-pyridinyl)pyridines were prepared. Cardiovascular activity of the obtained derivatives is discussed in comparison with that of the parent compounds.

[Potential cardiotonic agents. 6. Synthesis and cardiovascular properties of 5-(4-pyridinyl)-, 6-methyl-5-(4-pyridinyl)- and 6-methyl-5-phenyl-substituted 3-cyano-2-oxaalkyoxy-pyridines].

The headline compounds were prepared by the reaction of 2-chloropyridines 1-3 with the appropriate alcohols in presence of potassium hydroxide and the sodium alkoxides, respectively. Especially some of the 3-cyano-2-hydroxyalkoxy-5-(4-pyridinyl)pyridines showed remarkable positive inotropic potency and, additionally, a vasodilator activity. In spontaneously beating isolated guinea pig atria they had a greater activity than amrinone.

[Potential cardiotonic agents. 2. Synthesis and pharmacologic properties of 5-(pyri-4-yl)- and 5-phenyl substituted 3-cyano-6-methyl-2-oxaalkylaminopyridines].

The authors describe the preparation, the physicochemical properties and the results of evaluation of positive inotropic and vasodilator activities in a series of 5-(4-pyridinyl)- and 5-phenyl-substituted 3-cyano-6-methyl-2-oxaalkylamino-pyridines. Some of the compounds are comparable in their positive inotropic potency to that of amrinone and cause, additionally, a decrease in blood pressure.

[Potential cardiotonic agents. 1. Synthesis and pharmacologic properties of 3-cyano-2-oxaalkylamino-5-(4-pyridinyl)pyridines].

Synthesis, physicochemical properties and evaluation of positive inotropic and vasodilator activities are described in a series of substituted 2-amino-3-cyano-5-(4-pyridinyl)pyridines. Some of the 2-oxaalkylamino derivatives showed remarkable positive inotropic activities and, additionally, a decrease in blood pressure. The most potent compounds 11 and 13 have a greater activity than amrinone.

[Crystal modifications of 3-cyan-6-methyl-5-(pyrid-4-yl)-1,2-dihydropyrid-2-one (milrinone)].

The preparation and characterisation of crystalline alpha-, beta- and gamma modifications of 3-cyan-6-methyl-5-(4-pyrid-4-yl)-1,2-dihydropyrid-2-on e are described. The thermic transformation of alpha- and beta-modification into gamma-modification was proved by thermogravimetric analysis (t.g.