An exploratory study of ring closures of aryl radicals onto cyclopropyl- and oxiranyl-isocyanate acceptors.

The idea that ring closures of C-centred radicals onto isocyanates could be made permanent by designing the cyclised radical to undergo a rapid onward beta-scission, was investigated for the 2-(2-isocyanato)cyclopropylphenyl and 2-(2-isocyanato)oxiranylphenyl radicals. The radical precursors, trans- and cis-1-bromo-(2-isocyanatocyclopropyl)benzene and (2-bromophenyl)-3-isocyanatooxirane, were prepared from the corresponding bromophenylcyclopropane and bromophenyloxirane carboxylic acids via Curtius rearrangements of the derived azides. The structure of the trans-2-(2-isocyanato)cyclopropylphenyl radical prevents cyclization, however, it was shown that isomerisation to the analogous cis-radical occurred, probably by scission of the disubstituted cyclopropane bond followed by internal rotation of the resulting resonance stabilised diradical.

Radical ring closures of 4-isocyanato carbon-centered radicals.

The 2-(2-isocyanatophenyl)ethyl radical was generated from the corresponding bromide with tributyltin and tris(trimethylsilyl)silyl radicals and shown to ring close in the 6-endo-mode to afford 3,4-dihydro-1H-quinolin-2-one as the major product. Cyclization in the 5-exo-mode to produce 2,3-dihydroindole-1-carbaldehyde, after hydrogen abstraction, was a minor reaction. Rate constants for the two processes were estimated and compared with reaction enthalpies computed by the DFT method.

[Heart rupture in the acute period of myocardial infarction: prognostication and ways of prevention].

Clinical, instrumental, and biochemical examinations were carried out in 587 patients with transmural myocardial infarctions (381 patients with the first infarction and 206 ones with the repeated disease). Heart ruptures occurred in 5.7% of cases.

[The prognosis and prevention of cardiac muscle ruptures in myocardial infarct].

This article is based on the examination of 850 patients with acute transmural myocardial infarction, including 48 fatal cases in the result of external cardiac rupture. Immunological and biochemical indices of all patients have shown a high rate of necrotic processes in cardiac muscle in cases of heart rupture. The authors disclose the risk factors of cardiorrhexis and give recommendations for its prophylaxis.

[Change in the activity of creatine kinase and its MB isoenzyme as affected by partial and complete occlusion of the coronary artery in rats].

A model of different degree left coronary artery (LCA) occlusion in rats has been developed. The activity of creatine kinase and its cardiospecific MB isoenzyme was determined both in the cardiac muscle and blood plasma of 62 animals at different time after complete or partial LCA occlusion. A direct dependence of the decrease in the enzyme activity in the heart and hyperfermentemia on the degree of LCA occlusion has been established.