| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing in high optical purity (R)-2- hydroxy-4-phenylbutanoic acid useful as a pharmaceutical intermediate through a crystalline salt made from (R)-2-hydroxy-4-phenylbutanoic acid and (S)-3- methyl-2-phenylbutylamine. SOLUTION: This method of optical resolution for isolating the R-modification from (R,S)-2-hydroxy-4-phenylbutanoic acid comprises the following three steps: (A) (S)-3-methyl-2-phenylbutylamine is added to a solution containing (R,S)-2- hydroxy-4-phenylbutanoic acid to form its salt and the diastereomer thereof followed by selectively depositing the crystal of the salt from the solution; (B) as necessary, the salt thus deposited is purified by recrystallization; and (C) the aimed (R)-2-hydroxy-4-phenylbutanoic acid is isolated from the above salt. |
