| 摘要 |
<p>PURPOSE: To inexpensively racemize an unnecessary optically active aminoketone derivative 100 percent without passing through such a process that an intermediate is once formed from the derivative, isolating the intermediate is isolated and is newly reacted with an amine to racemize the derivative. CONSTITUTION: This derivative is shown by formula I (R<1> is a group of formula II; R<2> is an alkyl, etc.; R<3> and R<4> are each pyrrolidine, etc.; R<5> is a halogen, etc.). The derivative, for example, is obtained by treating and racemizing (-)-3- phenyl-5- 2(pyrrolidinylmethyl)butyryl}isoxazole with a weak acid such as hypochlorous acid having preferably >=4 pKa value in an organic solvent such as ethyl acetate preferably at 0-60 deg.C, then neutralizing the resultant substance with an aqueous solution of an alkali such as sodium hydrogencarbonate and racemizing an intermediate produced as a by-product with an equimolar amount of an amine such as pyrrolidine. Further, the solvent layer is washed with water, dried with anhydrous sodium sulfate and subjected to optical resolution by using an agent for optical resolution such as 10-camphorsulfonic acid.</p> |
