108549-23-1

921-26-6

100-51-6

108549-23-1

General procedure for the synthesis of diphenyl N,N'-diisopropylphosphoramidite from dichloro-N,N-diisopropylphosphoramidite and benzyl alcohol: 42 g (207.92 mmol) of dichloro-N,N-diisopropylphosphoramidite was placed in a 500 mL round-bottomed flask, and 300 mL of anhydrous tetrahydrofuran was added, and dissolved by stirring. Subsequently 66 mL (455.44 mmol, 46 g) of anhydrous triethylamine was added. The flask was cooled to 0°C in an ice-salt bath and 45 mL (416.67 mmol, 45 g) of anhydrous benzyl alcohol was added slowly and dropwise under nitrogen protection, keeping the reaction temperature close to 0°C. Upon completion of the reaction, the suspension was added dropwise and the formation of a white solid was observed. The reaction mixture was removed from the ice bath, returned to room temperature and stirring was continued for 3 hours. After stopping stirring, it was allowed to stand for 10 minutes for filtration and the solid was washed with tetrahydrofuran. The filtrate was collected and the solvent was removed by rotary evaporation to give the crude product. Without column chromatographic purification, 54.0 g of the oily product was obtained directly in 75.3% yield.