Patent US3923828A successfully refreshed from Google Patents.
US3923828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for separating N-methyl-nitrophthalimides
Assignee: General Electric Co
•
Filing: 1974-05-08
•
Granted: 1975-12-02
•
Expires: 1994-05-08
Abstract
Abstract N-methyl-4-nitrophthalimide can be separated from a mixture of the latter with N-methyl-3-nitrophthalimide by contacting the mixture of nitrophthalimides with a lower alkanol of from 1 to 2 carbon atoms and thereafter isolating the N-methyl-4nitrophthalimide from the alkanol solution containing the Nmethyl-3-nitrophthalimide.
Inventors
- 👤 Frank J Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:58
CPC Classifications
C; C07; C07D; C07D209/00; C07D209/02; C07D209/44; C07D209/48
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
44 words
IN THE PROCESS FOR ISOLATING N-METHYL-4-NITROPHTHALIMINE FROM A MIXTURE OF THE LATTER AND N-METHYL-3-NITROTHALIMIDE, THE IMPROVEMENT WHICH COMPRISES CONTACTING THE MIXTURE WITH A LOWER ALKANOL OF FROM 1 TO 2 CARBON ATOMS, SEPARATING THE ALKANOL SOLUTION RICH IN THE N-METHYL-3-NITROPHTHALIMIDE THEREBY ISOLATING THE N-METHYL-4-NITROPHTHALIMIDE.
Claim 2
Dependent Claim
44 words
IN THE PROCESS FOR ISOLATING N-METHYL-4-NITROPHTHALIMINE FROM A MIXTURE OF THE LATTER AND N-METHYL-3-NITROTHALIMIDE, THE IMPROVEMENT WHICH COMPRISES CONTACTING THE MIXTURE WITH A LOWER ALKANOL OF FROM 1 TO 2 CARBON ATOMS, SEPARATING THE ALKANOL SOLUTION RICH IN THE N-METHYL-3-NITROPHTHALIMIDE THEREBY ISOLATING THE N-METHYL-4-NITROPHTHALIMIDE.
Claim 3
Dependent Claim
11 words
The process as in claim 1 wherein the alkanol is methanol.
Claim 4
Dependent Claim
11 words
The process as in claim 1 wherein the alkanol is ethanol.
Claim 5
Dependent Claim
20 words
The process as in claim 1 wherein the treatment with the alkanol is conducted at a temperature above ambient temperature.
Claim 6
Dependent Claim
18 words
The process as in claim 1 wherein the treatment with the alkanol is conducted at essentially ambient temperature.
Claim 7
Dependent Claim
41 words
The process for separating N-methyl-4-nitrophthalimide from a mixture of the latter with N-methyl-3-nitrophthalimide which comprises contacting the aforesaid mixture with methanol, removing the methanol solution thereby separating the N-methyl-4-nitrophthalimide in essentially pure form and retaining the N-methyl-3-nitrophthalimide dissolved in the methanol.
Claim 8
Dependent Claim
41 words
The process for separating N-methyl-4-nitrophthalimide from a mixture of the latter with N-methyl-3-nitrophthalimide which comprises contacting the aforesaid mixture with methanol, removing the methanol solution thereby separating the N-methyl-4-nitrophthalimide in essentially pure form and retaining the N-methyl-3-nitrophthalimide dissolved in the methanol.
Claim 9
Dependent Claim
20 words
The process as in claim 6 wherein the treatment with the methanol is carried out at temperatures above ambient temperature.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |