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:
Nov. 27, 1990
Filed:
Apr. 25, 1989
Applicant:
Inventors:
Yoshihiro Yamamoto, Yokohama, JP;
Usaji Takaki, Fujisawa, JP;
Shinobu Aoki, Yokohama, JP;
Isao Hara, Yokohama, JP;
Assignee:
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09B / ;
U.S. Cl.
CPC ...
548457 ;
Abstract
Disclosed is a process for preparing an indigo compound in improved yield by reacting indole or other indole compound having no substituent at the 2- and 3-positions with an organic hydroperoxide in the presence of an additive selected from the group consisting of (1) a carboxyl compound and (2) a boric acid ester compound. The yield of the indigo compound can further be increased by using a metallic compound catalyst capable of oxidizing carbon atom at the 3-position of the indole compound, such as a compound of a metal of group 4A, 5A or 6A of the periodic table.