892112-24-2

76-83-5

123-08-0

892112-24-2

GENERAL METHODS: 4-Hydroxybenzaldehyde (0.8 g, 6.5 mmol) was dissolved in 10 mL of anhydrous dichloromethane with triphenylmethane chloride (1.0 g, 3.2 mmol) under nitrogen protection, and N,N-diisopropylethylamine (DIEA, 2.2 mL, 12.9 mmol) was added as a base. The reaction mixture was stirred at room temperature for 6 hours. After completion of the reaction, the reaction mixture was diluted with dichloromethane (100 mL) and the organic phase was washed three times with 0.1 M sodium hydroxide solution (3 x 100 mL). The organic layer was dried with anhydrous magnesium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by silica gel column chromatography with hexane/ethyl acetate (70:30, v/v) containing 1% triethylamine as eluent to give 4-(triphenylmethoxy)benzaldehyde (1.05 g, 82%). Subsequently, 4-(triphenylmethoxy)benzaldehyde (1.05 g, 2.66 mmol) was dissolved in 10 mL of tetrahydrofuran and sodium borohydride (0.25 g, 6.60 mmol) was added. The reaction mixture was stirred at room temperature for 6 hours. After completion of the reaction, it was diluted with dichloromethane (3 x 100 mL) and the organic phase was washed three times with water (100 mL). The organic layer was dried with anhydrous magnesium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by silica gel column chromatography with hexane/ethyl acetate (60:40, v/v) containing 1% triethylamine as eluent to give 4-(triphenylmethoxy)benzyl alcohol (0.845 g, 80%). Finally, 4-(triphenylmethoxy)benzyl alcohol (0.40 g, 1.01 mmol) was dissolved in 7 mL of dichloromethane and N,N-diisopropyl dichlorophosphoramidite (124 μL, 0.67 mmol) and N,N-diisopropylethylamine (DIEA, 348 μL, 2.68 mmol) were added. The reaction mixture was stirred for 1.5 h at room temperature. After completion of the reaction, it was diluted with dichloromethane and the organic phase was washed three times with cold water. The organic layer was dried with anhydrous magnesium sulfate and concentrated under reduced pressure to remove the solvent. The crude product was purified by silica gel column chromatography with hexane/ethyl acetate (85:15, v/v) containing 2% triethylamine as eluent to give the target product (0.74 g, 87%).