2-Cyanoethyl tetraisopropylphosphorodiamidite → HCID 90411800, compound

Participants

Reaction Steps

To a stirred solution of 14 (0.9 g, 1.4 mmol) in 20 ml of anhydrous dichloromethane was added diisopropylammonium tetrazolide (0.25 g) followed by 0.5 g (1.66 mmol) of 2-cyanoethyl N,N,N′,N′-tetraisopropylphosphordiamidite. In about 5 hrs another 0.04 g of 2-cyanoethyl N,N,N′,N′-tetraisopropylphosphordiamidite was added. The reaction was allowed to proceed for total 20 hrs and then concentrated. The resultant semi-solid was portioned between ethyl acetate and saturated NaHCO3. The organic phase was washed with saturated NaCl, dried over Na2SO4 and concentrated in vacuo. The crude phosphoramidite was precipitated twice by re-dissolving in small (˜5-10 ml) amount of ethyl acetate, diluting with hexane (100 ml), allowing to settle as an oil and decanting the liquid. Drying in vacuo afforded 1.1 g (93%) of 15 as a white amorphous solid. 31P NMR (DMSO-d6): δ 147.11, 146.16.

Provenance & Evidence