Method of producing DAI from DOPA, using one reaction vessel
US5486619A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1994 |
| Grant date | Jan 23, 1996 |
| Priority date | — |
| Expiry date | Apr 29, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D209/08
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method of producing and isolating 5,6-diacetoxyindole (DAI) in a single reaction vessel comprising the following steps: PA1 (a) preparing a first solution comprising dopa, water and a solubilizing agent selected from the group consisting of an acid having a pk.sub.a value equal to or less than 4 and a first base having a pk.sub.b value equal to or greater than 10; PA1 (b) preparing a second solution comprising an oxidant, a buffer and water; PA1 (c) mixing the first and second solutions to form a combined solution which is rendered oxygen-free and has a pH of from about 6 to about 9; PA1 (d) stirring the combined solution in an inert atmosphere until 5,6-dihydroxyindole (DHI) is substantially completely formed; PA1 (e) adding a derivatizing agent and a second base to the combined solution to form a final solution; PA1 (f) stirring the final solution until the DHI is substantially fully consumed; PA1 (g) cooling the final solution to precipitate DAI; PA1 (h) isolating the precipitated DAI.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.