反应详情

温度

25 °C

2-Cyanoethyl diisopropylchlorophosphoramidite (0.49 ml, 2.19 mmol) was added to a solution of 9 (0.83 g, 1.29 mmol) dissolved in 32 ml of anhydrous methylene chloride containing 0.67 ml of N,N-diisopropylethylamine. The reaction solution was stirred for 1.0 h at 25° C. under argon and then treated with 1.0 ml of methanol and poured into 300 ml of 5% sodium bicarbonate solution. The mixture was extracted with ethyl acetate (300 ml) and the extract was dried over sodium sulfate and evaporated. The crude product was purified by silica gel chromatography eluting with a gradient of 25-50% ethyl acetate in hexane (2% triethylamine). The pure phosphoramidite fractions were evaporated affording a homogenous oil: 0.61 g (56%) yield; TLC (1:1, ethyl acetate/hexane), Rf=0.62; 31P NMR (DMSO-d6) 147.82 (singlet). Anal. Calcd for C47H59N2O10P0.2 H2O: C, 66.68; H, 7.07; N, 3.31. Found: C, 66.46; H, 7.27; N, 2.94.

1. extractionThe mixture was extracted with ethyl acetate (300 ml)
2. dry with materialthe extract was dried over sodium sulfate
3. customevaporated
4. customThe crude product was purified by silica gel chromatography
5. washeluting with a gradient of 25-50% ethyl acetate in hexane (2% triethylamine)
6. customThe pure phosphoramidite fractions were evaporated
7. customaffording a homogenous oil
8. custom0.61 g (56%) yield