Patent US2821541A successfully refreshed from Google Patents.
US2821541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of dialkyl 2, 5-diarylamino-3, 6-dihydroterephthalates
Assignee: EIDP Inc
•
Filing: 1955-07-22
•
Granted: 1958-01-28
•
Expires: 1975-07-22
Abstract
No abstract record available.
Inventors
- 👤 William S Struve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:25
CPC Classifications
C; C07; C07C; C07C69/00; C07C69/74; C07C69/757; C09; C09B; C09B48/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
65 words
A PROCESS FOR PREPARING DIETHYL DIARYLAMINO DIHYDRO TEREPHTHALATE WHICH COMPRISES CARRYING OUT THE FOLLOWING STEPS UNDER NON-OXIDIZING CONDITIONS, CONDENSING TWO MOLS OF DIETHYL SUCCINATE TO DIETHYL SUCCINYL SUCCINATE IN AN INERT HIGH BOILING LIQUID IN THE PRESENCE OF AN ALKALINE CATALYST, NEUTRALIZING THE REACTION MIXTURE, CONDENSING THE DIETHYL SUCCINYL SUCCINATE PRESENT IN THE REACTION MIXTURE WITH 2 MOLS OF AN ARYLAMINE HAVING THE FOLLOWING FORMULA
Claim 2
Dependent Claim
65 words
A PROCESS FOR PREPARING DIETHYL DIARYLAMINO DIHYDRO TEREPHTHALATE WHICH COMPRISES CARRYING OUT THE FOLLOWING STEPS UNDER NON-OXIDIZING CONDITIONS, CONDENSING TWO MOLS OF DIETHYL SUCCINATE TO DIETHYL SUCCINYL SUCCINATE IN AN INERT HIGH BOILING LIQUID IN THE PRESENCE OF AN ALKALINE CATALYST, NEUTRALIZING THE REACTION MIXTURE, CONDENSING THE DIETHYL SUCCINYL SUCCINATE PRESENT IN THE REACTION MIXTURE WITH 2 MOLS OF AN ARYLAMINE HAVING THE FOLLOWING FORMULA
References Cited (Backward Citations)
US2577900A
Cited
US2734077A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |