Bis(p-nitrophenyl)-phosphate → 5,7-Dichloro-3-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)thiazolo[4,5-d]pyrimidin-2-one

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Reaction Conditions

Reaction Steps

A finely powdered mixture of 24 (3.7 g, 16 mmol), 1,2,3,5-tetra-O-acetyl-D-ribofuranose (5.3 g, 16 mmol) and bis(p-nitrophenyl)phosphate (20 mg) was heated at 170° C. for 10 min under reduced pressure. After cooling to room temperature the brown solid mass was dissolved in EtOAc (500 mL) and washed with saturated aqueous sodium bicarbonate (3×300 mL). The dried (Na2SO4) organic layer was evaporated to yield a syrup which was purified by silica gel column chromatography (4×40 cm) using toluene-EtOAc (5:1). The resulting syrup was crystallized from ethanol to give a colorless powder: yield 6.4 g, 80%: mp 125°-126° C.: 1H NMR (DMSO-d6) δ1.99, 2.06, 2.08 (3s, 9H, acetyl), 6.07 (d, J=3.40 Hz, 1H, C1,H), and other sugar protons. Anal. Calcd. for C16H15Cl2N3O8S: C, 40.01: H, 3.15: Cl, 14.76: N, 8.75: S, 6.68. Found: C, 40.20: H, 3.31: Cl, 14.79: N, 8.61: S, 6.66.

Provenance & Evidence