Patent US4812579A successfully refreshed from Google Patents.
US4812579A
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Process for producing N-substituted maleimides
Assignee: Mitsubishi Chemical Corp
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Filing: 1987-10-13
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Granted: 1989-03-14
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Expires: 2007-10-13
Abstract
Abstract A process for producing N-substituted maleimides which comprises heating maleic anhydride and an aromatic or aliphatic amine, or maleic acid monoamides obtained from them, in the presence of an ion exchange resin in an organic solvent to effect cyclodehydration.
Inventors
- 👤 Shunichi Doi
- 👤 Yasuyuki Takayanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:14
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/44; C07D207/444; C07D207/448; C07D207/452
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
43 words
A process for producing N-substituted maleimides which comprises heating maleic anhydride and an aromatic or aliphatic primary amine in the presence of an ion exchange resin in an organic solvent in the temperature range of 50° C. to 160° C. to effect cyclodehydration.
Claim 2
Dependent Claim
43 words
A process for producing N-substituted maleimides which comprises heating maleic anhydride and an aromatic or aliphatic primary amine in the presence of an ion exchange resin in an organic solvent in the temperature range of 50° C. to 160° C. to effect cyclodehydration.
Claim 3
Dependent Claim
22 words
A process according to claim 1, wherein the aromatic primary amine is aniline, naphthylamine, toluidine, dimethylaniline, chloroaniline, dichloroaniline, hydroxyaniline, nitroaniline or phenylenediamine.
Claim 4
Dependent Claim
20 words
A process according to claim 1, wherein the aliphatic primary amine is methylamine, ethylamine, propylamine, butylamine, benzylamine, cyclohexylamine or ethylenediamine.
Claim 5
Dependent Claim
31 words
A process according to claim 1, wherein the ion exchange resin is a strongly acidic ion exchange resin, a weakly acidic ion exchange resin, or a weakly basic ion exchange resin.
Claim 6
Dependent Claim
15 words
A process according to claim 1, wherein the organic solvent is an aromatic hydrocarbon solvent.
Claim 7
Dependent Claim
23 words
A process according to claim 1, wherein the organic solvent is a mixture of an aromatic hydrocarbon solvent and an aprotic polar solvent.
Claim 8
Dependent Claim
41 words
A process for producing N-substituted maleimides which comprises heating aromatic or aliphatic monoamides of maleic acid in the presence of an ion exchange resin in an organic solvent in the temperature range of 50° C. to 160° C. to effect cyclodehydration.
Claim 9
Dependent Claim
41 words
A process for producing N-substituted maleimides which comprises heating aromatic or aliphatic monoamides of maleic acid in the presence of an ion exchange resin in an organic solvent in the temperature range of 50° C. to 160° C. to effect cyclodehydration.
Claim 10
Dependent Claim
40 words
A process according to claim 7, wherein the aromatic or aliphatic monoamides of maleic acid is a product formed by the reaction of maleic anhydride with a corresponding amine, said monoamides being used without being separated from the reaction mixture.
Claim 11
Dependent Claim
22 words
A process according to claim 7, wherein the aromatic primary amine is aniline, naphthylamine, toluidine, dimethylaniline, chloroaniline, dichloroaniline, hydroxyaniline, nitroaniline, or phenylenediamine.
Claim 12
Dependent Claim
20 words
A process according to claim 7, wherein the aliphatic primary amine is methylamine, ethylamine, propylamine, butylamine, benzylamine, cyclohexylamine, or ethylenediamine.
Claim 13
Dependent Claim
31 words
A process according to claim 7, wherein the ion exchange resin is a strongly acidic ion exchange resin, a weakly acidic ion exchange resin, or a weakly basic ion exchange resin.
Claim 14
Dependent Claim
15 words
A process according to claim 7, wherein the organic solvent is an aromatic hydrocarbon solvent.
Claim 15
Dependent Claim
23 words
A process according to claim 7, wherein the organic solvent is a mixture of an aromatic hydrocarbon solvent and an aprotic polar solvent.
Claim 16
Dependent Claim
30 words
A process according to claim 1 wherein said ion exchange resin is present in an amount from 1 to 40% by weight based on the amount of the reaction liquid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |