360 mg (1.07 mmol) 3-[3-(4-Trifluoromethyl-phenyl)-benzo[d]isothiazol-6-yl]-propan-1-ol in 3 ml CH2Cl2 were treated with 100 μl (1.29 mmol) methanesulfonic acid chloride and 450 μl (3.23 mmol) triethylamine at 0° C. The solution was stirred at RT for 2 h, diluted with CH2Cl2 and washed with 1N HCl and dried over Na2SO4. Evaporation gave 350 mg (79%) crude Methanesulfonic acid 3-[3-(4-trifluoromethyl-phenyl)-benzo[d]isothiazol-6-yl]-propyl ester, which was directly subjected to the following reaction.
