1,4-Dioxane hydrochloride → 3,5-difluoro-4-[4-(2-fluorophenyl)-3-({[(1R)-1-(1-naphthyl)ethyl]amino}methyl)piperidin-1-yl]benzoic acid

Participants

Reaction Steps

To 135 mg of 4-[3-({(tert-butoxycarbonyl)[(1R)-1-(1-naphthyl)ethyl]amino}methyl)-4-(2-fluorophenyl)piperidin-1-yl]-3,5-difluorobenzoic acid was added 3.0 mL of a 4 M hydrogen chloride/1,4-dioxane solution, followed by stirring at room temperature overnight. The reaction mixture was concentrated under reduced pressure, and to the obtained residue were added chloroform and a saturated aqueous sodium hydrogen carbonate solution, followed by stirring, and the organic layer was then separated, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (methanol-chloroform) to obtain 111 mg of 3,5-difluoro-4-[4-(2-fluorophenyl)-3-({[(1R)-1-(1-naphthyl)ethyl]amino}methyl)piperidin-1-yl]benzoic acid as a colorless amorphous substance. The obtained amorphous substance was dissolved in chloroform, and hexane was added thereto to precipitate a white solid, which was collected by filtration to obtain 93 mg of 3,5-difluoro-4-[4-(2-fluorophenyl)-3-({[(1R)-1-(1-naphthyl)ethyl]amino}methyl)piperidin-1-yl]benzoic acid as a white solid.

Provenance & Evidence