Synthesis of N1-methyldesthiobiotin

Conclusions N₁-Methyldesthiobiotin was synthesized by starting with the ethyl ester of-ketodehydrodesthiobiotin.We express our gratitude to prof. V. V. Filippov for testing (III) for biotin activity.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1416–1418, June, 1973.     

A first estimate of triply heavy baryon masses from the pNRQCD perturbative static potential

Within pNRQCD we compute the masses of spin-averaged triply heavy baryons using the now-available NNLO pNRQCD potentials and three-body variational approach. We focus in particular on the role of the purely three-body interaction in perturbation theory. This we find to be reasonably small and of the order 25 MeV. Our prediction for the Ω _ccc baryon mass is 4900(250) MeV in keeping with other approaches. We propose to search for this hitherto unobserved state at B factories by examining the end point of the recoil spectrum against triple charm.     

Stability and spectral characteristics of 3-methyl-3-phenyl-1-arylphthalyl ions

3-Methyl-3-phenyl-1-aryphthalyl ions are more stable than 3,3-diphenyl ions, but less stable than 3,3-dimethyl-1-arylphthalyl ions. The effect of substituents at C₍₃₎ and C₍₁₎ on stability and spectral characteristics of the ions is discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 742–746, June, 1985.     

Intramolecular rearrangements

It has been shown that S--aminoalkyl derivatives of 2-mercaptopyrimidine and 2-mercapto-4, 6-diaminopyrimidine, containing primary and secondary amino groups, undergo S N rearrangement in neutral or weakly alkaline solution, with the formation of the corresponding aminothiols. In the case of derivatives of 2-mercapto-4, 6-diaminopyrimidine, however, the S N rearrangement proceeds more slowly, apparently as a result of the difficulty of formation of the intermediate cyclic compound.For part II, see [9].