Patent ID: 7285660

Claim:
A process for the preparation of a compound of the formula (IV) which consists of: a) the reaction of a triazole of the formula wherein R 2 is 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 the group consisting of C 1 -C 4 acyloxy, aryloxy, halogen, and mixtures thereof; in the presence of from 1 to 1.5 moles of a Lewis acid for every mole of (II) and of a solvent selected from the group consisting of a halogenated hydrocarbon, an ether, an aromatic hydrocarbon, and mixtures thereof having a reflux temperature, said reaction step a) preformed 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 a compound of the 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 suspsension while maintaining a temperature below 20° C.