Crystal form of N- (trans-4-isopropylcyclohexylcarbonyl) -D-phenylalanine

摘要

New crystal forms of N-(trans-4-isopropylcyclohexylcarbonyl)-D-phenylalanine, also known as nateglinide, may be produced by dissolving nateglinide in any of its forms, including solvates, in an organic solvent to form a solution followed by precipitation of nateglinide from the solution, and isolating and drying the precipitated crystal form of nateglinide. The precipitation of nateglinide may be induced either by cooling the solution, or by addition of another solvent which is miscible with the first solvent but in which nateglinide is only poorly soluble, or by combination of the two. Depending on the solvent a specific crystal form of nateglinide may be obtained, e.g., the R'-type crystal form of nateglinide produced by the described method has a different melting point, infra red spectra and X-ray diffraction patterns from the previously known crystal forms of nateglinide.