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:
Feb. 23, 1988
Filed:
Nov. 15, 1985
Atsuyoshi Yamauchi, Naka, JP;
Seiya Iguchi, Mitaka, JP;
Yuzo Ono, Takaishi, JP;
Hiroshii Kimura, Kamakura, JP;
Satoshi Morita, Yokosuka, JP;
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JP;
Abstract
A process for producing an indole which comprises reacting an aniline and a diol in the presence of a catalyst to produce a reaction mixture containing the indole, unreacted aniline and by-products, condensing the reaction mixture to obtain a liquid reaction product, recovering the unreacted aniline from the liquid reaction product, reducing the contents of specified by-products in the recovered aniline below specified levels and reutilizing the resulting recovered aniline. To reduce the contents of the specified by-products in the recovered aniline below specified levels, it is preferred to subject the liquid reaction product or an aniline fraction separated therefrom to a heat-treatment and then to distillation. In the above manner, the recovered aniline can be reutilized in the reaction without causing the activity of the catalyst to deteriorate.