57.6 mg of sodium hydride (as a 60% w/w dispersion in mineral oil) were added to a solution of 197.8 mg of 4-acetamidophenol in 4 ml of dimethylformamide cooled in an ice-water bath and the resulting mixture was stirred at this temperature for 5 minutes. A solution of 371.5 mg of 2-bromomethyl-6-methoxybenzothiazole [prepared as described in step (a) above] in 1 ml of dimethylformamide was added to the reaction mixture, the temperature of the mixture was elevated to room temperature and the mixture was stirred for 2 hours. At the end of this time, a saturated aqueous ammonium chloride solution was added to the reaction mixture and the mixture was extracted with ethyl acetate. The resulting extract was washed consecutively with water and an aqueous sodium chloride solution and them dried over anhydrous sodium sulfate. The solvent was then removed by evaporation under reduced pressure and the resulting residue was purified by column chromatography through silica gel using a 1:2 by volume mixture of hexane and ethyl acetate to give 399.1 mg (yield 93%) of the title compound as a solid having a melting point of 145°-147° C.
