Toluene → Pyrrolidine Cholesterol Phosphoramidite

Beteiligte Stoffe

Reaktionsschritte

Compound 66 (0.15 g, 0.158 mmol) was coevaporated with toluene (5 mL). To the residue N,N-tetraisopropylammonium tetrazolide (0.0089 g, 0.079 mmol) was added and the mixture was dried over P2O5 in a vacuum oven for overnight at 40° C. The reaction mixture was dissolved in the mixture of anhydrous acetonitrile/dichloromethane (2;1, 1 mL) and 2-cyanoethyl-N,N,N′,N′-tetraisopropylphosphorodiamidite (0.0714 g, 0.0781 mL, 0.237 mmol) was added. The reaction mixture was stirred at ambient temperature for overnight. The completion of the reaction was ascertained by TLC (1;1 ethyl acetate:hexane). The solvent was removed under reduced pressure and the residue was dissolved in ethyl acetate (10 mL) and washed with 5% NaHCO3 (4 mL) and brine (4 mL). The ethyl acetate layer was dried over anhydrous Na2SO4 and concentrated under reduced pressure. The resulting mixture was chromatographed (50:49:1, EtOAc:Hexane:triethlyamine) to afford 67 as white foam (0.152 g, 84%).

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