Process for preparing bis(ether anhydrides) using alkylamine derived bisimides having low melting temperatures
US5719295A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 1996 |
| Grant date | Feb 17, 1998 |
| Priority date | — |
| Expiry date | May 23, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D307/89
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for making bis(ether anhydrides) employs alkylamines having low melting temperatures thus allowing for novel intermediate process steps for preparing bis(ether anhydrides). The alkylamines have alkyl groups which contain at least three carbon atoms and have boiling temperatures in the range of 48.degree. to 250.degree. C. at atmospheric pressure. As a result of using these amines, liquid alkylamines now can be employed in the imidization process step. The N-alkyl nitrophthalimides prepared from the recovered imidization product according to this invention can now be purified using liquid/liquid extraction or vacuum distillation. The alkyl nitrophthalimides prepared according to this invention provide for displacement reactions which now can be run at a high solids level. Likewise, the exchange reaction can be run at a higher solids level, and thus achieves an efficiency level which is higher than conventional processes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.