Title:
RACEMIZATION OF AMINOKETONE DERIVATIVE
Document Type and Number:
Japanese Patent JP2999146
Kind Code:
B2
Abstract:
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 (R1 is a group of formula II; R2 is an alkyl, etc.; R3 and R4 are each pyrrolidine, etc.; R5 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°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.
Inventors:
Seiki Nagahara
Hideki Tanada
Setsuo Yoshino
Ryuichi Mita
Hideki Tanada
Setsuo Yoshino
Ryuichi Mita
Application Number:
JP28706795A
Publication Date:
January 17, 2000
Filing Date:
November 06, 1995
Export Citation:
Assignee:
Mitsui Chemicals, Inc.
International Classes:
C07D275/02; A61K31/42; A61K31/425; A61P25/00; C07B55/00; C07C221/00; C07C225/16; C07D261/08; (IPC1-7): C07C221/00; C07C225/16; C07D261/08; C07D275/02
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