METHOD OF PREPARING CIS-NUCLEOSIDE ANALOGS, THEIR SALTS AND ESTERS Russian patent published in 1999 - IPC

FIELD: molecular biology methods. SUBSTANCE: cis-nucleoside analogs having general formula II: (II), wherein X is sulfur or oxygen atom, Y sulfur, and R₂ residue of purine or pyrimidine base or their analog or derivative, are prepared by interaction of desired preliminarily or in situ silylated purine or pyrimidine base or their analog or derivative with compound of general formula III: (III), wherein X and R are as above and Z is sulfur or oxygen, in solution in presence of Lewis acid V: (V) where R₃, R₄ and R₅, independent of each other, are selected from group including: hydrogen, C₁-C₂₀-alkyl (e.g. methyl, ethyl, t-butyl), optionally halogen- substituted (F,Cl,Br,I) C₁-C₂₀-alkoxy (e.g. methoxy) or C₆-C₂₀-alkoxy (e.g. phenoxy), C₇-C₂₀-arylalkyl (e.g. benzyl), optionally halogen-substituted C₁-C₂₀-alkyl or C₁-C₂₀-alkoxy (e.g. p-methoxybenzyl), C₆-C₂₀-aryl (e. g. phenyl) optionally substituted by halogens (F, Cl, Br,I), C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy, or trialkylsilyl; R₆ is selected from group including: halogen, C₁-C₂₀-sulfonate esters optionally substituted by halogens (e.g. trifluorometanesulfonate), optionally halogen- substituted C₁-C₂₀-alkyl esters (e.g. trifluoroacetate), multivalent halides (e. g. triiodide), trisubstituted silyl groups having general formula (R)(R₄)(R₅), wherein R₃, R₄ and R₅ are saturated or unsaturated C₆-C₂₀-aryl compounds, optionally substituted C₆-C₂₀-alkylsulfenyl, optionally substituted C₁-C₂₀-alkoxyalkyl, and trialkylsiloxy. Products show antiviral activity. EFFECT: simplified process and increased yield. 19 cl, 9 ex