To a suspension of 1-acetyl-4-benzyl-1,2-dihydro-5-methyl-3H-pyrazol-3-one (0.75 g) in acetonitrile (5 mL) and tetrahydrofuran (3 mL) was added potassium carbonate (0.675 g) under stirring at room temperature. After the mixture was stirred at 50° C. for 1 hour, 1-bromo-2,3,4,6-tetra-O-pivaloyl-α-D-glucopyranosyl bromide (2.27 g) was added to the mixture. The mixture was stirred at 50° C. for 6 hours. After the reaction completed, the insoluble materials were removed by filtration, and the filtrate was concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (eluent: ethyl acetate/n-hexane=1/10 to 1/5) to give 1-acetyl-4-benzyl-5-methyl-3-(2,3,4,6-tetra-O-pivaloyl-β-D-glucopyranosyloxy)-1H-pyrazole (1.88 g).
