Imidazole → 1,3,5-tri-O-benzoyl-2-O-imidazolyl-sulfonyl-alpha-L-ribofuranose

Participants

Reaction Steps

107.0 g (0.232 mole) of the compound (13) was dissolved in 1070 ml of dichloromethane and 214 ml of dimethylformamide, to which 62.5 g (37.2 ml, 0.463 mole) of sulfuryl chloride was added dropwise at a low temperature (−10 to −78° C.). The resulting solution was stirred at room temperature for 3 hours and then cooled in an ice-bath. The solution was stirred while 157.8 g (2.32 mole) of imidazole was added portionwise at the rate keeping the temperature of reaction mixture under 5° C. The resulting mixture was stirred at room temperature for 20 hours, after which 400 ml of ice-water was added. The aqueous layer was extracted three times with 100 ml of dichloromethane (3×100 ml). The combined organic solution was washed with 200 ml of brine and dried over MgSO4. The solvent was removed under reduced pressure and dimethylformamide was removed under high vacuum. The syrupy residue was coevaporated with 100 ml of 2-propanol under reduced pressure to obtain a white solid product (14), which was used for the next reaction without further purification.

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