Patent US3045040A successfully refreshed from Google Patents.
US3045040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of 2, 5-diarylamino-3, 6-dihydroterephthalic acid esters
Assignee: BASF SE
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Filing: 1959-09-08
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Granted: 1962-07-17
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Expires: 1979-09-08
Abstract
No abstract record available.
Inventors
- 👤 Deuschel Werner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:47
CPC Classifications
C; C09; C09B; C09B48/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
102 words
IN A PROCESS FOR THE PRODUCTION OF A 2,5-DIARYLAMINO3,6-DIHYDROTEREPHTHALIC ACID ESTER WHEREIN A SUCCINIC ACID ESTER IS CONDENSED WITH THE AID OF AN ALKALI METAL ALCOHOLATE IN AN ORGANIC SOLVENT TO THE DIALKALI METAL SALT OF THE CORRESPONDING SUCCINYLOSUCCINIC ACID ESTER, AND THE SUCCINYLOSUCCINIC ACID ESTER IS CONDENSED IN THE PRESENCE OF AN ACID-REACTING SUBSTANCE WITH AN ARYLAMINO COMPOUND TO FORM THE CORRESPONDING 2,5-DIARYLAMINO-3,6-DIHYDROTEREPHTHALIC ACID ESTER, THE IMPROVEMENT WHICH COMPRISES: CARRYING OUT SAID CONDENSATION OF THE SUCCINIC ACID ESTER IN A CARBOXYLIC ACID DIALKYLAMIDE SELECTED FROM THE GROUP CONSISTING OF DIMETHYLFORMAMIDE, DIMETHYLACETAMIDE, DIETHYLFORMAMIDE, DIETHYLACETAMIDE, N-METHYL-2PYRROLIDONE, N-ETHYL-2-PYRROLIDONE AND N-METHYLPIPERIDONE AS THE ORGANIC SOLVENT.
Claim 2
Dependent Claim
102 words
IN A PROCESS FOR THE PRODUCTION OF A 2,5-DIARYLAMINO3,6-DIHYDROTEREPHTHALIC ACID ESTER WHEREIN A SUCCINIC ACID ESTER IS CONDENSED WITH THE AID OF AN ALKALI METAL ALCOHOLATE IN AN ORGANIC SOLVENT TO THE DIALKALI METAL SALT OF THE CORRESPONDING SUCCINYLOSUCCINIC ACID ESTER, AND THE SUCCINYLOSUCCINIC ACID ESTER IS CONDENSED IN THE PRESENCE OF AN ACID-REACTING SUBSTANCE WITH AN ARYLAMINO COMPOUND TO FORM THE CORRESPONDING 2,5-DIARYLAMINO-3,6-DIHYDROTEREPHTHALIC ACID ESTER, THE IMPROVEMENT WHICH COMPRISES: CARRYING OUT SAID CONDENSATION OF THE SUCCINIC ACID ESTER IN A CARBOXYLIC ACID DIALKYLAMIDE SELECTED FROM THE GROUP CONSISTING OF DIMETHYLFORMAMIDE, DIMETHYLACETAMIDE, DIETHYLFORMAMIDE, DIETHYLACETAMIDE, N-METHYL-2PYRROLIDONE, N-ETHYL-2-PYRROLIDONE AND N-METHYLPIPERIDONE AS THE ORGANIC SOLVENT.
References Cited (Backward Citations)
US2821541A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-07-16 | 1966-01-15 | 1966-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-07-16 | 1970-01-15 | 1970-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-07-16 | 1974-01-15 | 1974-07-17 | $7700.00 | Window Closed / Lapsed |