Water → 4-{4-[4-(3,3-Dimethyl-butyl)-piperazin-1-yl]-butoxy}-3-fluoro-benzoic acid

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Reaction Steps

Sodium hydroxide (0.5 g, 13.2 mmol) and water (5 ml) were added to a solution of 4-{4-[4-(3,3-dimethyl-butyl)-piperazin-1-yl]-butoxy}-3-fluoro-benzoic acid ethyl ester from Example E72.2 (1.35 g, 3.3 mmol) in dioxan (20 ml). The mixture was stirred for 1 h at room temperature then heated at 60° C. for 20 h. Solvents were concentrated in vacuo and azeotroped with toluene. The residue was purified by flash chromatography on silica gel (eluant; 1% 35% ammonia:19% methanol:80% chloroform) to yield the title compound (0.85 g, 67%).

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