Method for preparing oxydiphthalic anhydrides using guanidinium salt as catalyst
US6706897B1 · kind B1 · utility
9Cited by
9References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 24, 2003 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | Feb 24, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/567
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Oxydiphthalic anhydrides such as 4-oxydiphthalic anhydride are prepared by the reaction of a halophthalic anhydride with an alkali metal carbonate such as potassium carbonate. The reaction proceeds in the presence of a hexaalkylguaninium halide or &agr;,&ohgr;-bis(pentaalkylguanidinium)alkane halide as a phase transfer catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.