METHOD FOR OPTICAL RESOLUTION OF THREO-2-HYDROXY-3-(2'-AMINOPHENYLTHIO)-3-(4'-METHOXYPHENYL)PROPIONIC ACID

摘要

PURPOSE:To obtain the titled compound having coronary vasodilator effect in high purity and high yield with ease, by action of optically active p-triethylamine as a resolving agent on propionic acid derivatives. CONSTITUTION:Optically active p-triethylamine (TEA) and a solvent such as methanol are added to threo-2-hydroxy-3-(2'-aminophenylthio)-3-(4'-methoxyphenyl)propionic acid (TPA) of the formula, followed by heating and dissolving to form a supersaturated solution, which is seeded with a small amount of a TPA.TEA salt having a lower solubility in the above-mentioned solvent of two types of diastereomer salts if necessary. The seeded solution is then cooled, and a precipitated sparingly soluble salt is separated to obtain the aimed compound. EFFECT:Since this method requires no special operation at all as compared with the conventional methods and produces the salt having good crystallinity without oiliness, labor for purification can be saved.