Process for the regiospecific sulfonation of sulfonyl substituted 2-aminonaphthalenes and fiber reactive azo dyes made from the products of said process
US5082963A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1986 |
| Grant date | Jan 21, 1992 |
| Priority date | — |
| Expiry date | Nov 24, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B62/507
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of isomerically pure sulfonic acids of 2-aminonaphthalenes having a fiber reactive substituent of the formula --(SO.sub.2 X) wherein X is --CH.sub.2 --CH.sub.2 --Z and Z is a substituent such as thiosulfato, phosphato or sulfato. The process comprises a first step of acylating the amino group of the substituted 2-aminonaphthalene to form a N-acyl derivative of the formula, R--CO--NH--A--SO.sub.2 X wherein A represents a naphthalene nucleus. The N-acyl derivative is then sulfonated to provide an essentially isomerically pure sulfonic acid derivative of the formula R--CO--NH--A(--SO.sub.2 X, --SO.sub.3 H). Depending upon the position of the --SO.sub.2 X group in the starting material, the sulfonation reaction product will have one of the following isomeric ring positions for the sulfonyl and sulfo groups, respectively; 5:7 or 7:5 or 6:8 or 8:6. Exemplary products are 2-acetylamino-5-(beta-sulfatoethylsulfonyl)-naphthalene-7-sulfonic acid or 2-acetylamino-7-(beta-sulfatoethylsulfonyl)-naphthalene-5-sulfonic acid or 2-acetylamino-6-(beta-sulfatoethylsulfonyl)-naphthalene-8-sulfonic acid or 2-acetylamino-8-(beta-sulfatoethylsulfonyl)-naphthalene-6-sulfonic …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.