2-(1'-Imidazoylsulfonyl)-1,3,5-tri-O-benzoyl-alpha-D-ribofuranose synthesis

Yield:97614-42-1 76%

Reaction Conditions:

Stage #1: 1,3,5-tri-O-benzoyl-α-D-ribofuranosidewith thionyl chloride;N,N-dimethyl-formamide in dichloromethane at -15 - 20;
Stage #2: 1H-imidazole in dichloromethane at 0 - 20;

Steps:

1

The synthesis of compound vii: The compound vi (2.81mmol) was dissolved in 13 ml dry dichloromethane and 3.5ml dry DMF, and SO₂Cl₂ (0.0079mmol) was slowly added while stirring the solution at -15°C. After it was stirred at -15°C for about 30 minutes, the solution was naturally warmed up to a room temperature, reacting for 3 hours. Then the solution was added with imidazole (0.0407mmol) for three times at 0°C. The mixed solution was stirred at a room temperature for 15 hours. The reaction solution was diluted with CH₂Cl₂ (26ml) added, and washed with ice water (35ml). The water layer was extracted with CH₂Cl₂. Then the organic layers were combined and then dried over anhydrous sodium sulfate for over 4 hours, and then drawn off under a reduced pressure to obtain light yellow syrup. The syrup was separated and purified by silica gel column (gradient elution, petroleum ether: acetone) to obtain the white solid compound vii (76.0%). ¹H NMR(CDCl₃) δppm: 7.00～8.10 (m, 15H, OBz), 6.71 (d, J=4.4Hz, 1H, H-1), 5.59 (dd, 1H, H-3), 5.25 (dd, 1H, H-2), 4.56～4.81 (m, 3H, H-4, H-5). M.p.128～129°C.

References:

EP2177527,2010,A1 Location in patent:Page/Page column 11