Catalyzed M-C coupling reactions in the synthesis of σ-(pyridylethynyl)dicarbonylcyclopentadienyliron complexes.

The reactions between terminal ethynylpyridines, (trimethylsilyl)ethynylpyridines and cyclopentadienyliron dicarbonyl iodide were studied under Pd/Cu-catalyzed conditions to develop a synthetic approach to the σ-alkynyl iron complexes Cp(CO)Fe-C[triple bond, length as m-dash]C-R (R = -, -, -pyridyl). Depending on the catalyst and reagents used, the yields of the desired σ-pyridylethynyl complexes varied from 40 to 95%. In some cases the reactions with -ethynylpyridine gave as byproduct the unexpected binuclear FePd μ-pyridylvinylidene complex [Cp(CO)Fe{μ-η(C):η(C)-κ(N)-C[double bond, length as m-dash]C(H)(-CHN)}(μ-CO)PdI].

Crystal structure of μ-carbonyl-1:2κ:-carbonyl-1κ-(1η-cyclo-penta-dien-yl)iodido-2κ-[μ-2-(pyridin-2-yl)ethene-1,1-diyl-1κ:2κ,]ironpalladium(-) benzene monosolvate.

The reaction of Cp(CO)FeI with 2-ethynyl-pyridine under Sonogashira conditions [5% PdCl(PPh), 10% CuI, THF-NEt (2:1)] afforded the title binuclear μ-pyridyl-vinyl-idene FePd complex () as a benzene solvate, [FePd(CH)(CHN)I(CO)]·CH, in a very low yield rather than the expected iron -pyridyl-ethynyl complex Cp(CO)Fe-C≡C-(2-CHN). The Fe and Pd atoms in are bridged by carbonyl and pyridyl-vinyl-idene ligands, the pyridyl N atom being bonded to the palladium atom. The use of equimolar amounts of PdCl increases the yield of to 12%.

[Pharmacodynamics of allapinine during long-term infusion in patients with chronic ischemic heart disease and frequent ventricular extrasystole].

During a prolonged (24-hour) intravenous administration in a dose of 126 mg, allapinine produced a stable pronounced antiarrhythmic effect in 90% of the patients with frequent premature ventricular contraction and adverse reactions in the central nervous system in 65% of the cases. However, the latter effect of allapinine is short-term and ceased independently without altering the infusion rate. More serious adverse effects (hypotensive reactions, proarhythmic effects) occurred in 4% of the cases.

[Allapinin pharmacokinetics after its single intravenous administration].

Allapinin after i.v. bolus infusion in a dose of 30 mg is relatively quickly eliminated from blood (in patients without congestive heart failure half-elimination period is 2.