Color control & stability in acetaminophen
US5399760A · kind A · utility
1Cited by
5References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 11, 1993 |
| Grant date | Mar 21, 1995 |
| Priority date | — |
| Expiry date | Aug 11, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C231/24
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method is provided for purifying crude N-acetyl-para-aminophenol (APAP) containing color bodies or their precursors, the method comprising: a) forming a solution of the crude APAP; and b) subsequently contacting the solution with substoichiometric quantifies of an acetylating agent for a sufficient period of time to convert said color bodies or their precursors to substantially non-color bodies/stable, colorless substances; said quantities of acetylating agent provided is such that substantially none of the APAP is converted to other compounds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.