Process for the cyclization of orthobenzoylbenzoic acid
US4966984A · kind A · utility
3Cited by
1References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 8, 1989 |
| Grant date | Oct 30, 1990 |
| Priority date | — |
| Expiry date | Nov 8, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/487
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The process for the cyclization of orthobenzoylbenzoic acid into anthraquinone comprising heating orthobenzoylbenzoic acid in the solid phase at a temperature between about 300.degree. C. to 400.degree. C. in the presence of a superactive bleaching earth. The invention also comprises a process for the separation of phthalic acid and any phthalic anhydride impurities from orthobenzoylbenzoic acid prior to its cyclization into anthraquinone through the use of said earth at a temperature from 200.degree. C. to 250.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.