Methanol → HCID 18633465, Verbindung

A solution of 3.06 g of 5-bromo-2'-deoxycytidine and 2.3 g of p-toluenesulfonyl chloride in 50 ml of pyridine was stirred at 4° C. for 24 hours. An additional 1.91 g of p-toluenesulfonyl chloride were added and stirring was continued at 4° C. for an additional 22 hours. 20 ml of methanol were added, the mixture was stirred at room temperature for 30 minutes and then evaporated. The crude product was subjected to flash chromatography on a column of silica gel using ethyl acetate/methanol (9:1) for the elution, there being obtained 2.26 g of 5-bromo-2'-deoxy-5'-O-p-toluenesulfonylcytidine in the form of a white solid of melting point 168° C. (decomposition).