New synthesis of 5,6-dihydrothiazolo[3,2-b][1,2,4]triazoles

Russian Journal of Organic Chemistry -     

Solving boundary-value problems ofx k -analytic functions for a semicircle

Integral representations of x^k-analytic functions (k=const>0) in terms of boundary values of analytic functions are given. Using these integral representations, three boundary-value problems of x^k-analytic functions for a semicircle are solved by quadratures. Bibliography: 4 titles. Translated fromObchyslyuval’na ta Prykladna Matematyka, No. 76, 1992, pp. 3–12.     

Thietane ring as a novel protecting group

A novel protecting group for NH functionality of heterocycles, a thietane ring, was proposed. It can be readily introduced by alkylation of NH-heterocycles with 2-chloromethylthiirane. Removal of the thietane protecting group is performed via oxidation to thietane 1,1-dioxide with hydrogen peroxide in acetic acid and subsequent treatment with sodium alkoxide.     

Heterocyclization of 3,5-dibromo-1-(thiiran-2-ylmethyl)-1H-1,2,4-triazole into 5-substituted 2-bromo-5,6-dihydrothiazolo[3,2-b][1,2,4]triazoles

Russian Journal of Organic Chemistry -     

Reactions of 1,2,4-triazole derivatives with a “model” thiirane

Reactions of 3-mono- and 3,5-disubstituted 1,2,4-triazoles with a “model” thiirane, 8-bromo-1,3-dimethyl-7-(thiiran-2-ylmethyl)-3,7-dihydro-1H-purine-2,6-diones proceed at the positions N¹ and N² of the triazole ring and yield 7-(5-R-3-R′-1,2,4-triazol-1-yl)methyl- and/or 7-(5-R′-3-R-1,2,4-triazol-1-yl)methyl-1,3-dimethyl-6,7-dihydro[1,3]thiazolo[2,3-f]-purine-2,4-(1H,3H)-diones. 3-Methylsulfonyl-1,2,4-triazole reacted regiospecifically at the position N¹ forming 1,3-dimethyl-7-[(3-methyl-sulfonyl-1,2,4-triazole-1-yl)-methyl]-6,7-dihydro[1,3]thiazolo-[2,3-f]purine-2,4(1H,3H)-dione.     

8-halo-1,3-dimethyl-7-(thiiran-2-ylmethyl)-3,7-dihydro-1<Emphasis Type="Italic">H</Emphasis>-purine-2,6-diones,model thiiranes for investigating reactions with nucleophiles

For the study of thiirane reactions with nucleophiles 8-halo-1,3-dimethyl-7-(thiiran-2-ylmethyl)-3,7-dihydro-1H-purine-2,6-diones that did not form polymeric products through intramolecular heterocyclization into dihydrothiazolopurine derivatives were selected as model compounds. The possibility to employ the model thiiranes for the study of reactions with various nucleophiles was demonstrated.     

Structure and luminescence of thietane-containing 1,2,4-triazoles

New thietane-containing 1,2,4-triazole derivatives were synthesized, and their structure was determined by ¹³C and ¹H NMR spectroscopy and mass spectrometry. The electronic absorption spectra of the new compounds in the ultraviolet and visible regions and their photoluminescence and luminescence excitation spectra were analyzed, and photoluminescence quantum yields were estimated.