Method for purifying diacetylrhein
US5756782A · kind A · utility
1Cited by
5References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1997 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Mar 18, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2603/24
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The present invention discloses a method for preparing purified diacetylrhein to be used in the preparation of drugs which includes the steps of: PA0 (a) suspending a diacetylrhein containing various impurities and, in particular, relatively high amounts of aloe-emodin derivatives, in a mixture of organic solvent/water; PA0 (b) adding a tertiary amine; PA0 (c) adding to the solution obtained a salt of an acid and of an alkali metal or of an alkaline-earth metal; PA0 (d) carrying out a hydrolysis in a weakly acidic medium; PA0 (e) collecting the purified diacetylrhein, by filtration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.