A mixture of 3-(4-bromobutyl)-5,5-dimethyl-4-thiazolidinone (3.42 g), 1-(2-benzothiazolyl)piperazine (3.10 g), K2CO3 (6.19 g), NaI (250 mg) and acetonitrile was heated at 65° C. (bath temperature) under nitrogen. After 19 hours, TLC analysis (5% methanol/methylene chloride) showed the absence of starting bromide and the presence of a major product, Rf =0.29. The reaction mixture was cooled to room temperature, ethyl acetate (100 ml) was added and the mixture filtered. The filtrate was concentrated in vacuo to a solid which was redissolved in hot ethyl acetate causing a solid to precipitate. The mixture was filtered and the filtrate concentrated in vacuo to an off-white solid. Chromatography of the crude product by HPLC (Waters Prep 500, one silica gel column, 5% methanol/methylene chloride) yielded 4.05 g of a solid, mp 99.5°-100.5° C. It was recrystallized from methylene chloride/hexane to give 2.83 g of fine needles, mp 101°-102° C.
