Benzyl chloroformate → HCID 69071738, 화합물

1.3 g (6 mmol) 2-(4-bromo-phenylamino)-ethanol are dissolved in 150 mL toluene, treated with 0.93 mL (1.1 eq.) benzyloxycarbonylchloride and 6.3 mL (1.05 eq.) 1N aqueous sodium hydroxide solution. The reaction mixture is stirred at room temperature for 18 hours, then the aqueous phase separated and extracted with ethyl acetate and water. The combined organic phases are washed with water and brine, then evaporated to dryness to yield 2.1 g crude (4-bromo-phenyl)-(2-hydroxy-ethyl)-carbamic acid benzyl ester, which is reacted further without additional purification by dissolution in 100 mL dichloromethane, addition of 5 mL (excess) pyridine, cooling to 5° C. and dropwise addition in 10 minutes of 2.45 g p-toluenesulfonic acid anhydride in 20 mL dichloromethane. The reaction mixture is stirred an additional 2 hours at room temperature and poured onto ice, then extracted at 10° C. with dichloromethane and an aqueous solution of sodium bicarbonate. The combined organic phases are dried with sodium sulfate and evaporated to yield the desired product as a light brownish resin, which is used without further purification.