Ketoprofen → Dexketoprofen

Participants

Reaction Conditions

Reaction Steps

To (±)-2-(3-benzoylphenyl)propionic acid (1200 g, 4.719 mol) were added methyl-t-butyl ether (hereinafter abbreviated to "MTBE") (4.8 L) and water (600 g, water/KET=0.50) and the mixture was dissolved with heating. Then, (S)-(+)-3-methyl-2-phenylbutylamine (388 g, 2.377 mol) was added dropwise with stirring at 50° C. to 55° C. This reaction solution was cooled to precipitate a crystal and then reheated from 35° C. to 50° C. This solution was again cooled and then reheated from 40° C. to 45° C. This solution was cooled slowly to 10° C. and stirred at 5° C. to 10° C. for one hour. Then, the crystal precipitated was filtered, and the filter cake was washed three times with cold MTBE (1 L) and dried. In this manner, a diastereomer salt (741 g, 1.775 mol) of (S)-(+)-2-(3-benzoylphenyl)propionic acid with (S)-(+)-3-methyl-2-phenylbutylamine was obtained. The yield of the product based on (S)-(+)-2-(3-benzoylphenyl)propionic acid contained in the starting material was 75.2% and the optical purity was 99.1% e.e.

Provenance & Evidence