Bromide ion → 3-[4-[1-(1,2-Benzisothiazol-3-yl)-4-piperazinyl]butyl]-5,5-dimethyl-4-thiazolidinone hydrochloride

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(4-bromobutyl)-5,5-dimethyl-4-thiazolidinone (3.50 g), 1-(1,2-benzisothiazol-3-yl)piperazine hydrochloride (3.70 g), K2CO3 (6.34 g), NaI (330 mg) and acetonitrile (175 mL) was heated at 95° C. (bath temperature) under nitrogen. After 21 hours, TLC analysis (silica gel, 5% MeOH/CH2Cl2) showed the absence of starting bromide and the presence of a major product, Rf =0.33. The reaction mixture was cooled to room temperature, ethyl acetate (150 mL) was added, and the mixture filtered. The filtrate was concentrated in vacuo to an oil which was triturated with ethyl acetate. The mixture was filtered again and the filtrate, after concentration, was chromatographed (Waters Prep 500, one silica gel column, 3% MeOH/CH2CL2) to give 3.48 g of a viscous oil. The oil was dissolved in diethyl ether (500 mL), the solution filtered to remove a fluffy solid, and the filtrate acidified to pH=1 (hydrion paper) with an HCl/diethyl ether solution. The resultant salt (3.23 g) was recrystallized from ethanol/ethyl acetate yielding 2.29 g of white needles, mp 222°-227° C.

Provenance & Evidence