2-[2-(Benzyl-{2-[2-(2-hydroxy-ethoxy)ethoxy]ethyl}amino)ethyl]phthalimide 33 (2.774 g, 6.7 mmol) was dissolved in mixture of pyridine (20 mL) and dichloromethane (100 mL) and cooled in an ice bath. Methanesulfonyl chloride (0.63 mL, 8 mmol) was added and the resulting solution was stirred at 0° C. for 16 h. (The progress of the reaction was followed by TLC using a 1:1 mixture of 40% acetone in hexanes and chloroform as the eluent. The starting material has Rf=0.35, while the product has Rf=0.50.) Saturated aqueous sodium bicarbonate was added, and after 30 min of stirring, the organic phase was washed with 0.5 M hydrochloric acid and again with saturated aqueous sodium bicarbonate. The solution was dried over sodium sulfate and solvent was removed under reduced pressure. The resulting crude oily product 34 (3.152 g, 96%) was used in the next step without further purification. CIMS (M+): 491.
