Synthesis of 6-substituted tetrazolo[1,5-c]pyrimidin-5(6H)ones: new modification of 3'-azido-3'-deoxythymidine

An efficient method for the preparation of 6-methyltetrazolo-[1,5-c]pyrimidin-5(6H)ones using as the precursors 4-chloro-1,2-dihydro-1-methyl-2-oxopyrimidines is described. The method is also extended to the synthesis of novel tetrazole analogue of 3'-azido-3'-deoxythymidine (AZT).

Selective deuteration of 4-N-methylcytosines

A convenient photochemical method of preparation of mono-, di- and trideuterate 4-N-methylcytosines of high isotopic purity is described. These products were obtained by photo-decarboxylation of pyrimidinyl glycines or their alpha, alpha-dideuterated derivatives in water or in deuterium oxide. [2, 2H2]Glycine derivatives were prepared by hydrogen-deuterium exchange in alkaline solution.

Stacking-controlled phototransformations of the 5-fluorouracil residues in dinucleotide model compounds

5-Fluorouracil residues can form cyclobutane-type photodimers in a direct excitation stacking-controlled process. The stacking also has an important effect on the photohydration of uracil and 5-fluorouracil in our model compounds 5RUra(CH2)35FUra, where R = H, CH3, C2H5, C3H7, F or Cl.

The structural study of internal [2+2] photodimers of the derivatives of 1,1'-trimethylene-bis-(5-fluoro) uracil

The structure of internal [2+2] photodimers of 1,1'-trimethylene-bis-(5-fluoro) uracil derivatives has been studied. All investigated compounds have cis-syn geometry with puckered endocyclic cyclobutane ring and chair-like conformation of 1,3-diazacycloheptane ring.

The effective synthesis of uridylyl/3'-5'/5-methylcytidylyl/3'-5'/guanosine

The triester method was adapted to the synthesis of uridylyl/3'-5'/5-methylcytidylyl/3'-5'/guanosine. As the protecting groups 4-methoxy-5,6-dihydro-2H-pyran for 2'-OH and 5'-OH groups of uridine and 2'-OH group of 5-methylcytidine, methoxymethylidene for I:3'-cis-diol system of guanosine, and benzoyl for the amino groups of 5-methylcytidine and guanosine were used. The obtained product was characterised by UV, electrophoresis, chromatography, an enzymatic digestion and alkaline hydrolysis.