Process for the preparation of indigo compounds
US5187283A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1991 |
| Grant date | Feb 16, 1993 |
| Priority date | — |
| Expiry date | Nov 21, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B7/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.