5-(2-bromoethyl)-6-chloro-1,3-dihydroindol-2-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:99.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To de-ionized water (1.5 Lit), was added 5-(2-bromoethyl)-6-chloro-oxindole (75 g) and 1-(1,2-benzisothiazol-3-yl)piperazine (132 g) at 30-35° C. The mixture was slowly heated under stirring to 98-100° C. over 60-80 minutes. The resultant mass was stirred for 4-5 hours at 98-100° C. After completion of reaction as monitored by HPLC, the suspended solid material was filtered at 98-100° C. The wet cake so obtained was suspended in de-ionized water (1.5 Lit) and heated to 90-95° C. and further maintained at this temperature for 30 minutes. The solid suspension was filtered at 90-95° C. The wet cake was further added to isopropyl alcohol (1.5 Lit) and the resultant mass was heated to reflux and maintained at reflux for 1 hour. The mass was further cooled to 30-35° C. and stirred for 2 hours at 30-35° C. The solids were filtered and washed with isopropyl alcohol (75 ml) and dried under vacuum at 50-55° C. for 7-8 hours till moisture content was not more than 1.0% w/w. The mixture was slowly heated The resultant mass was stirred for 4-5 hours at 98-100° C After completion of reaction the suspended solid material was filtered at 98-100° C The wet cake so obtained heated to 90-95° C. further maintained at this temperature for 30 minutes The solid suspension was filtered at 90-95° C The wet cake was further added to isopropyl alcohol (1.5 Lit) the resultant mass was heated to reflux maintained at reflux for 1 hour The mass was further cooled to 30-35° C. stirred for 2 hours at 30-35° C The solids were filtered washed with isopropyl alcohol (75 ml) dried under vacuum at 50-55° C. for 7-8 hours till moisture content