Synthesis of certain bis(phthalic anhydrides)
US3965125A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 8, 1971 |
| Grant date | Jun 22, 1976 |
| Priority date | — |
| Expiry date | Feb 8, 1991 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L75/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Monomeric high molecular weight dianhydrides or tetraacids can be produced by the nucleophilic coupling of a halo substituted phthalimides acid and an aliphatic or aromatic compound having polyfunctional groups capable of reacting with the halo moiety of the phthalinide followed by hydrolysis and dehydration. Specifically, 4-chlorophthalate sodium salt is converted to an imide to reduce side reactions with the carboxylic acid groups prior to reaction with 4,4'-disodiumdiphenylene oxide sulfone or 2,2-di (4-sodium phenoxide) propane. After the reaction of the imide and the sulfone or propane compounds, the diimide formed is converted to the corresponding dianhydride.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.