A mixture of 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole (2.36 g, 10.7 mmole), K2CO3 (2 g, 14.5 mmol) and 2-(4-bromobutyl)anisole (2.4 g, 10 mmol) in acetonitrile (100 ml) was heated at reflux for 2.5 hours. At the end of reaction, the solvent was removed. The residue was extracted into dichloromethane (200 ml) and filtered. The dichloromethane solution was concentrated. The crude oil obtained was purified on a flash chromatography column. The material thus purified was a light yellow oil (2.73 g, 53%). This oil was dissolved in ethanol and treated with maleic acid (607 mg, 1.0 eq) in ethanol. The 4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-(2'-methoxyphenyl)butylpiperidine maleate crystals formed on concentration and subsequent cooling to 0° C. These were collected and dried to yield 2.05 g, m.p.=132°-133° C.
