A 2 liter round bottom flask equipped with stirring rod, thermo pocket, reflux condenser and nitrogen inlet was charged with 50 gm (0.2 moles) of 11-chlorodibenzo[b,f][1,4]-thiazepine and 500 cc n-butanol and the mixture was stirred for 15 min. at room temperature. The resulting solution was combined with 39 gm (0.22 mole) of 1-(2-hydroxyethoxy)ethylpiperazine, 56.2 gm (0.40 mole) of potassium carbonate and 16.89 gm (0.10 mole) of potassium iodide. The reaction mixture was heated at gentle reflux for 12 hrs and a sample of the reaction mixture was analyzed by HPLC. The analysis revealed that starting material remains less than 1%. The reaction mixture was cooled to room temperature and treated with 1000 cc 1N hydrochloric acid solution to get a pH in between 1 to 2. The layers (aqueous and nonaqueous reaction solvent) were separated and the aqueous layer was extracted with 500 cc toluene and pH was adjusted between 8 to 9 by addition of sodium carbonate. The layers were separated and aqueous layer was again extracted with 500 cc toluene. The organic layers (n-butanol and toluene) were combined and washed with 2×500 cc of water. The solvent was distilled under vacuum at 70 to 80° C. to afford 47.5 gm oil. HPLC area %: 98.9
