Reaction #417912

Reaction equation

1,4-anhydro-2-O-benzyl-5-O-[bis(4-methoxyphenyl)(phenyl)methyl]D-ribitol

N,N-diisopropylethylamine

2-cyanoethyl-N,N-diisopropylchlorophosphoramidite

1-methylimidazole

→

pure product

Yield 42.6%

1,4-Anhydro-2-O-benzyl-5-O-[bis(4-methoxyphenyl)(phenyl)methyl]-3-O-[(2-cyanoethoxy)(dipropan-2-ylamino)phosphanyl]-D-ribitol

Yield 42.6%

Solvents

DCM

Conditions

Workup

1. 1
   OtherThe reaction was then quenched with methanol (5 mL)
2. 2
   workup.STIRRINGstirred for 5 min
3. 3
   OtherThe solvent was then removed in vacuo
4. 4
   Otherthe residue was purified by flash chromatography

Procedure

To a cooled solution (0° C.) of 1,4-anhydro-2-O-benzyl-5-O-[bis(4-methoxyphenyl)(phenyl)methyl]D-ribitol (1.60 g, 3.04 mmol) and N,N-diisopropylethylamine (1.59 mL, 9.11 mmol) in DCM (20 mL), 2-cyanoethyl-N,N-diisopropylchlorophosphoramidite (1.44 g, 6.08 mmol) and 1-methylimidazole (0.12 mL, 1.519 mmol) were added. The reaction mixture was warmed to ambient temperature and stirred for 90 min. The reaction was then quenched with methanol (5 mL) and stirred for 5 min. The solvent was then removed in vacuo, and the residue was purified by flash chromatography using 20% ethyl acetate in hexane to obtain 0.94 g (1.293 mmol, 42.6%) of the pure product. LCMS: for C42H51N2O7P calculated 726.3. found 727.3 [M+H]+ and 749.4 [M+Na]+. 31P NMR (400 MHz, CD3CN) δ: 149.94, 149.70.

Source