The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 1990
Filed:
Apr. 08, 1988
Hiroshi Maki, Chiba, JP;
Shigeru Sasaki, Chiba, JP;
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
A process for producing an N,N-diethylaminophenol is disclosed, comprising subjecting an aminophenol to reductive alkylation with acetaldehyde in the presence of a solvent, a catalyst, and hydrogen is disclosed, in which the reaction mixture from which the catalyst has been removed is subjected to distillation while maintaining the temperature of the bottom at 160.degree. C. or lower to substantially remove the unreacted acetaldehyde and the solvent, the residual bottom is distilled while maintaining the temperature of the bottom at 200.degree. C. or lower to recover a crude N,N-diethylaminophenol as a distillate, and the recovered crude N,N-diethylaminophenol is contacted with a solvent to which at least one of acid sulfites and dithionites has been added, said solvent being substantially incompatible with the N,N-diethylaminophenol, in an inert gas atmosphere, followed by precipitating and recovering the N,N-diethylaminophenol by cooling. N,N-Diethylaminophenols of high purity can be obtained in high yield without involving problems, such as production of large quantities of waste water and sludge, corrosion of materials, and coloring with time.