Process for the production of N-(hydroxyphenyl) maleimides
US4289699A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1979 |
| Grant date | Sep 15, 1981 |
| Priority date | — |
| Expiry date | Oct 26, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D207/448
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
N-(hydroxyphenyl) maleimides of the general formula ##STR1## where R' stands for H, CH.sub.3, C.sub.2 H.sub.5, F, Cl, Br or I and n is an integer of 1-5 are produced by treating the corresponding maleamic acid or by treating the ester of said N-(hydroxyphenyl) maleimide at a temperature of 0.degree.-150.degree. C. in the presence of at least one dehydrating agent selected for the group consisting of oxides and oxyacids of sulfur or phosphorus and alkali metal and alkaline earth metal salts of the said oxyacids. The corresponding maleamic acid can be obtained by reacting an aminophenol having one or more hydroxyl groups on its phenyl nucleus with maleic anhydride. The esters of the N-(hydroxyphenyl maleimide) can be obtained by reacting said aminophenol and said maleic anhydride in the presence of a conventional acid anhydride dehydrating agent and a conventional imide-forming cyclization catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.