Patent US2806855A successfully refreshed from Google Patents.
US2806855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of pyrrolidone carboxylic
Assignee: —
•
Filing: —
•
Granted: 1957-09-17
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Expires: 1974-09-17
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:51
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/18; C07D207/22; C07D207/24; C07D207/26; C07D207/273; C07D207/277; C07D207/28
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
145 words
A PROCESS FOR THE PRODUCTION OF SUBSTANTIALLY PURE PYRROLIDONE CARBOXYLIX ACID WHICH COMPRISES SEPARATING PYRROLIDONECARBOXYLIC ACID FROM A MIXTURE OF GLUTAMIC ACID AND PYRROLIDONECARBOXYLIC ACID BY TREATING SAID MIXTURE IN AN AQUEOUS SYSTEM WITH A SATURATED KETOENE HAVING BETWEEN 3 TO 5 CARBON ATOMS PER MOLECULE, IN WHICH AQUEOUS SYSTEM THE KETONE COMPRISES BETWEEN ABOUT 85% AND ABOUT 96% OF THE TOTAL WEIGHT OF THE LIQUIDS, AND WATER COMPRISES BETWEEN ABOUT 15% AND ABOUT 4% OF THE TOTAL WEIGHT OF THE LIQUIDS, SEPARATING SOLID GLUTAMIC ACID FROM THE RESULTING PYRROLIDONE CARBOXYLIC ACID-CONTAINING SOLUTION, ADDING A SATURATED STRAIGHT CHAIN MONOHYDRIC ALCOHOL HAVING A BOILING POINT BETWEEN ABOUT 100* C. AND ABOUT 200*C. TO THE PYRROLIDONE CARBOXYLIC ACID SOLUTION, CONCENTRATING THE RESULTING SOLUTION AT LEAST TO THE POINT OF SATURATION WITH RESPECT TO PYRROLIDONE CARBOXYLIC ACID, AND CRYSTALLIZING AND SPARATING PYRROLIDONE CARBOXYLIC ACID FROM THE RESULTING SOLUTION.
Claim 2
Dependent Claim
145 words
A PROCESS FOR THE PRODUCTION OF SUBSTANTIALLY PURE PYRROLIDONE CARBOXYLIX ACID WHICH COMPRISES SEPARATING PYRROLIDONECARBOXYLIC ACID FROM A MIXTURE OF GLUTAMIC ACID AND PYRROLIDONECARBOXYLIC ACID BY TREATING SAID MIXTURE IN AN AQUEOUS SYSTEM WITH A SATURATED KETOENE HAVING BETWEEN 3 TO 5 CARBON ATOMS PER MOLECULE, IN WHICH AQUEOUS SYSTEM THE KETONE COMPRISES BETWEEN ABOUT 85% AND ABOUT 96% OF THE TOTAL WEIGHT OF THE LIQUIDS, AND WATER COMPRISES BETWEEN ABOUT 15% AND ABOUT 4% OF THE TOTAL WEIGHT OF THE LIQUIDS, SEPARATING SOLID GLUTAMIC ACID FROM THE RESULTING PYRROLIDONE CARBOXYLIC ACID-CONTAINING SOLUTION, ADDING A SATURATED STRAIGHT CHAIN MONOHYDRIC ALCOHOL HAVING A BOILING POINT BETWEEN ABOUT 100* C. AND ABOUT 200*C. TO THE PYRROLIDONE CARBOXYLIC ACID SOLUTION, CONCENTRATING THE RESULTING SOLUTION AT LEAST TO THE POINT OF SATURATION WITH RESPECT TO PYRROLIDONE CARBOXYLIC ACID, AND CRYSTALLIZING AND SPARATING PYRROLIDONE CARBOXYLIC ACID FROM THE RESULTING SOLUTION.
References Cited (Backward Citations)
US2112329A
Cited
US2528267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-09-16 | 1961-03-18 | 1961-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-09-16 | 1965-03-18 | 1965-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-09-16 | 1969-03-18 | 1969-09-17 | $7700.00 | Window Closed / Lapsed |