stirred the product was filtered off and washed with water and dried to obtain 1 41 grams 75 of 5 2 4 1 2 benizisothiazol 3 yl 1 piperazinyl ethyl 6 chloro 1 3 dihydro 2h indol 2 one the crude product was purified by ipa and or thf the product matched the spectra of a standard nmr and showed the correct retention time by hplc with 98 0 assay the melting point of the compound was found to be 218 u00b0 c 220 u00b0 c and was found to conform with the melting point of 218 u00b0 220 u00b0 c as disclosed in u s pat no 5 206 366 in a 50 ml 3 necked round bottom flask there were placed 1 gram 4 56 mmol of 3 piperazinylbenzo d isothiazole 2 5 grams 10 86 mmol of 6 chloro 5 2 chloroethyl indolin 2 one 50 mg of potassium iodide 1 64 grams 11 88 mmol of potassium carbonate the contents of the flask were heated to 90 u00b0 c the reaction was monitored by hplc after completion of the reaction 50 ml of dm water was added to the reaction mixture and stirred the product was filtered off and washed with water and dried to obtain 1 41 grams 75 of 5 2 4 1 2 benzisothiazol 3 yl 1 piperazinyl ethyl 6 chloro 1 3 dihydro 2h.