[Potential cardiotonic agents. 4. Synthesis, cardiovascular activity, molecular and crystal structure of 5-phenyl- and 4-(4-pyridinyl)-substituted 2(1H)-pyridinethiones]. / Potentielle Kardiotonika. 4. Mitteilung5: Darstellung, kardiovaskuläre Wirksamkeit, Molekül- und Kristallstruktur von 5-phenyl- und 5-(pyrid-4-yl)-substituierten 1,2-Dihydro-pyrid-2-thionen.

Cyclisation of the vinylogous amidinium salt 1 or the 4-ethoxy- and 4-morpholino-3-butene-2-ones, respectively, 4 and 6 with cyano-thioacetamide yielded the 5-(4-pyridinyl)-, 6-methyl-5-(4-pyridinyl)- and 6-methyl-5-phenyl-, respectively, substituted 3-cyano-2(1H)-pyridinethiones 3, 5 and 7. The 2(1H)-pyridinethiones 3, 5 and 7a as well as the in 3-position unsubstituted or carbamoyl substituted derivatives 8 and 9 were obtained from the corresponding 2-chloro-pyridines and potassium sulfide, too. Especially compound 5 showed remarkable positive inotropic potency and, additionally, vasodilator activity. The molecular and crystal structure of 5 have been determines by X-ray structure analysis. Based on the molecular structure charge distribution and electrostatic potential were evaluated. The results are discussed in comparison with those of milrinone.