Process for the manufacture of indigoid dyes
US4151170A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 1976 |
| Grant date | Apr 24, 1979 |
| Priority date | — |
| Expiry date | Dec 16, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B7/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for the manufacture of indigoid dyes, wherein a functional derivative of the anthranilic acid of the general formula I ##STR1## in which A completes a mono- or polynuclear, substituted or unsubstituted aromatic ring, PA1 X represents a hydrogen atom or a protective group for the free amino group which can form an anhydro derivative with the carboxyl group in the ortho-position, Is reacted with nitromethane in the presence of a base or with a salt of nitroacetic acid to give the .omega.-nitro-o-amino-acetophenone derivative of the general formula II ##STR2## in which A and X are as defined in formula I, and this intermediate is condensed by heating with acids to give the indigo compound of the general formula III ##STR3## in which A is as defined in formula I.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.