73 mg (0.16 mmol) Methanesulfonic acid 4-[3-(4-bromo-phenyl)-benzo[d]isothiazol-6-yl]-but-3-ynyl ester in 1 ml DMA were treated with 35 μl (0.5 mmol) azetidine for 48 h. The solution was diluted with ether and aqueous Na2CO3, the phases were separated and the inorganic layer was extracted with ether. The combined organic phases were washed with brine, dried over Na2SO4. Column chromatography on silica gel with a gradient CH2Cl2 to CH2Cl2:MeOH 8:1 gave 22.2 mg (33%) 6-(4-Azetidin-1-yl-but-1-ynyl)-3-(4-bromo-phenyl)-benzo[d]isothiazole as brown oil, MS: 397(MH+, 1Br).
