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. 16, 1993
Filed:
Nov. 21, 1991
Yoshihiro Yamamoto, Yokohama, JP;
Usaji Takaki, Fujisawa, JP;
Shinobu Aoki, Yokohama, JP;
Yoshihisa Inoue, Yokohama, JP;
Isao Hara, Kanagawa, JP;
Mitsui Toatsu Chemicals, Inc., Tokyo, JP;
Abstract
An indigo compound is prepared from a corresponding indole compound which is unsubstituted at the 2- and 3- positions. The indole compound and an organic hydroperoxide are reacted in the presence of a catalyst which is a metal selected from the group consisting of the metals of Groups 4, 5 and 6 of the periodic table or a compound of the metal. The reaction is conducted while taking out water from a reaction system, said water being that introduced in the reaction system or formed during the reaction, or while controlling the amount of water, which is introduced in the reaction system, at a level not greater than 1 mole per mole of the indole compound.