US2900311A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of acetoacetic esters by distillation
Assignee: Union Carbide Corp
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Filing: 1952-10-11
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Granted: 1959-08-18
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Expires: 1972-10-11
Abstract
No abstract record available.
Inventors
- 👤 Amelio E Montagna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:07
CPC Classifications
C; C07; C07C; C07C67/00; C07C67/48; C07C67/60; C07C67/52; C07C67/54
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
115 words
IN A DISTILLATION PROCESS FOR PURIFYING AN ACETOACETIC ESTER, THE IMPROVEMENT CONSISTING OF RAPID PURIFICATION OF SAID ESTER WITH RESPECT TO IMPURITIES WITH BOILING POINTS NEAR THAT OF THE KETO ISOMER, WHICH COMPRISES TREATING SAID ACETOACETIC ESTER WITH ABOUT 0.01 TO 1.0 PART FOR EACH 100 PARTS OF THE ESTER BY WEIGHT OF AN ALKALINE SUBSTANCE SO AS TO CONTINUOUSLY SUPPLY THE ENOLIC FORM OF THE ESTER WHILE VAPORIZING SAID ENOLIC ESTER UNDER REDUCED PRESSURE AT A TEMPERATURE NOT HIGHER THAN 100*C. AND DISTILLING THE VAPORS THUS PRODUCED OVER-HEAD FREE OF ALKALINE SUBSTANCES AND THE KETO ISOMER, AND ALLOWING SUCH DISTILLATE OF ENOLIC ESTER THUS OBTAINED TO REVERT TO AN EQUILIBRIUM MIXTURE OF THE ISOMERS.
Claim 2
Dependent Claim
115 words
IN A DISTILLATION PROCESS FOR PURIFYING AN ACETOACETIC ESTER, THE IMPROVEMENT CONSISTING OF RAPID PURIFICATION OF SAID ESTER WITH RESPECT TO IMPURITIES WITH BOILING POINTS NEAR THAT OF THE KETO ISOMER, WHICH COMPRISES TREATING SAID ACETOACETIC ESTER WITH ABOUT 0.01 TO 1.0 PART FOR EACH 100 PARTS OF THE ESTER BY WEIGHT OF AN ALKALINE SUBSTANCE SO AS TO CONTINUOUSLY SUPPLY THE ENOLIC FORM OF THE ESTER WHILE VAPORIZING SAID ENOLIC ESTER UNDER REDUCED PRESSURE AT A TEMPERATURE NOT HIGHER THAN 100*C. AND DISTILLING THE VAPORS THUS PRODUCED OVER-HEAD FREE OF ALKALINE SUBSTANCES AND THE KETO ISOMER, AND ALLOWING SUCH DISTILLATE OF ENOLIC ESTER THUS OBTAINED TO REVERT TO AN EQUILIBRIUM MIXTURE OF THE ISOMERS.
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) | 1962-08-17 | 1963-02-16 | 1963-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-08-17 | 1967-02-16 | 1967-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-08-17 | 1971-02-16 | 1971-08-18 | $7700.00 | Window Closed / Lapsed |