A mixture of methyl 1,2,4-triazole-3-carboxylate (1.27 g, 0.01 mole) and 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (5.04 g, 0.01 mole) was melted and then 0.095 g of p-toluenesulfonic acid was added thereto. The reaction mixture was reacted for 3 hours, while maintaining the temperature of the reaction mixture at 95±5° C. And then, the reaction mixture was crystallized with 25 ml of methanol to give 4.85 g of 1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-1,2,4-triazole-3-carboxylic acid methyl ester (yield: 85%).
