Patent ID: 7285659

Claim:
A process for the preparation of a compound of formula (IV) which consists of: a) the reaction of a triazole of the formula wherein R 2 represents a C 1 -C 4 alkoxycarbonyl, arylalkoxycarbonyl, carboxyl, cyano, carboxyamide group with a protected ribofuranose of the formula wherein Pg represents a group protecting the hydroxyl function and R 1 represents a leaving group selected from among C 1 -C 4 acyloxy, aryloxy and halogen; in the presence of from 1 to 1.5 moles of a Lewis acid for every mole of (II) and a solvent selected from the group consisting of a halogenated hydrocarbon, an ether, an aromatic hydrocarbon, and mixtures thereof, said solvent having a reflux temperature, said reaction step a) performed at a reaction temperature between −10° C. and the reflux temperature of the solvent; and b) the removal of the Pg groups and the conversion of the R 2 group of the compound obtained of the formula wherein Pg and R 2 have the meanings given above, into a carboxyamide group, to give the compound of formula (IV), wherein the triazole (I), ribofuranose (II), and solvent are provided to the reaction step a) as a pre-cooled suspension and the Lewis acid is added to the pre-cooled suspension while maintaining a temperature below 20° C.