Synthesis and the crystal structure of 4-(2-deoxy-.beta.-D-erythro-pentofuranosyl)-6-methyl-1,2,4-triazin-3-(4H)-one 1-oxide, a structural analog of thymidine

Abstract

Condensation of pyruvaldehyde dimethyl acetal with thiosemicarbazide, followed by methylation and cyclization, gave 3-(methylthio)-6-methyl-l,2,4-triazine, which was converted to 6-methyl-1,2,4-triazin-3(4fí)-one 1-oxide by treatment with sodium methoxide and by selective oxidation and hydrolysis. Following silylation, this intermediate was condensed with blocked 2-deoxyribofuranosyl chloride, providing the anomeric nucleoside mixture, which was separated and deblocked to furnish the title compound. X-ray analysis of this nucleoside was carried out to confirm its structure and to study its conformation.