Title:
PURIFICATION OF KETO ACID
Document Type and Number:
Japanese Patent JP3204538
Kind Code:
B2
Abstract:
PURPOSE: To industrially and effectively remove by-produced colored substances and purify the keto acid derivative by adding a hydrogenation catalyst to a reaction solvent containing the crude keto acid derivative obtained from a N,N-dialkyl-m-aminophenol and phthalic acid and subsequently hydrogenating the crude keto acid derivative.
CONSTITUTION: When a keto acid derivative of the formula (R1, R2 are 1-6C alkyl) is obtained by reacting a N,N-dialkyl-m-aminophenol with phthalic anhydride and subsequently purified, the crude colored keto acid derivative of the formula containing a small amount of colored substances such as rhodamine is dissolved in a reaction solvent, mixed with a hydrogenation catalyst, hydrogenated in a reaction solvent and subsequently subjected to recrystallization, etc., to recover the keto acid derivative from the reaction solution. The method is advantageous, since an alkali, etc., is not used, and neutralized effluent water, etc., is not discharged. The keto acid derivative having a good color tone can be obtained by the foregoing simple process.
Inventors:
Naoya Sakamoto
Daikichi first
Daikichi first
Application Number:
JP15250192A
Publication Date:
September 04, 2001
Filing Date:
June 11, 1992
Export Citation:
Assignee:
Mitsui Chemicals, Inc.
International Classes:
C07C227/40; C07C227/42; C07C229/52; (IPC1-7): C07C229/52; C07C227/40; C07C227/42
Domestic Patent References:
| JP6270350A | ||||
| JP3261756A | ||||
| JP5013310A | ||||
| JP4852708A |
Attorney, Agent or Firm:
Itsuro Makino