Selective acylation of hydroxy-amino-arylsulfonic acids
US4379937A · kind A · utility
4Cited by
2References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1981 |
| Grant date | Apr 12, 1983 |
| Priority date | — |
| Expiry date | Sep 23, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C309/51
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
An improved process for selectively N-acylating hydroxy-amino-arylsulfonic acids is disclosed wherein the hydroxy-amino-arylsulfonic acid is dissolved in water by treatment with an alkaline lithium salt, such as lithium hydroxide, and the acylation is conducted while maintaining the pH at about 3-6. The N-acyl-hydroxy-amino-arylsulfonic acids are useful as dyestuff precursors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.