Patent US3871977A successfully refreshed from Google Patents.
US3871977A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic process for the manufacture of alpha-ketoglutarate esters
Assignee: Pfizer Inc
•
Filing: 1974-06-07
•
Granted: 1975-03-18
•
Expires: 1994-06-07
Abstract
Abstract Continuous process for the production of a mixture of delta monoalkyl Alpha -ketoglutarate, dialkyl Alpha -ketoglutarate and the corresponding ketals by electrolysis of 2-furoic acid in acidic alcoholic solvent.
Inventors
- 👤 Charles J V Scanio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:19
CPC Classifications
C; C25; C25B; C25B3/00; C25B3/20; C25B3/23; C25B3/01; C25B3/07
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
97 words
A CONTINUOUS PROCESS FOR PRODUCING A MIXTURE OF $ MONOESTERS AND DIESTERS OF A-KETOGLUTARIC ACID AND THE CORRESPONDING KETALS THEREOF WHICH COMPRISES ELECTROLYSIS OF A SOLUTION OF 2-FUROIC ACID IN ALCOHOLIC SOLVENT CONTAINING ACID CATALYST AT A CONCENTRATION OF FROM ABOUT 0.01 TO 1 MOLE PERLITER, WHEREIN SAID ALCOHOLIC SOLVENT IS AN ALKANOL OF FROM ABOUT ONE TO FIVE CARBON ATOMS, AND WHEREIN SAID ACID CATALYST IS A REACTION INERT ACID OF PKA LESS THAN ABOUT 2.5, AND CONTINUING SAID ELECTROLYSIS UNTIL A SUBSTANTIAL AMOUNT OF SAID MIXTURE OF ESTERS AND KETALS OF A-KETOGLUTARIC ACID IS FORMED.
Claim 2
Dependent Claim
97 words
A CONTINUOUS PROCESS FOR PRODUCING A MIXTURE OF $ MONOESTERS AND DIESTERS OF A-KETOGLUTARIC ACID AND THE CORRESPONDING KETALS THEREOF WHICH COMPRISES ELECTROLYSIS OF A SOLUTION OF 2-FUROIC ACID IN ALCOHOLIC SOLVENT CONTAINING ACID CATALYST AT A CONCENTRATION OF FROM ABOUT 0.01 TO 1 MOLE PERLITER, WHEREIN SAID ALCOHOLIC SOLVENT IS AN ALKANOL OF FROM ABOUT ONE TO FIVE CARBON ATOMS, AND WHEREIN SAID ACID CATALYST IS A REACTION INERT ACID OF PKA LESS THAN ABOUT 2.5, AND CONTINUING SAID ELECTROLYSIS UNTIL A SUBSTANTIAL AMOUNT OF SAID MIXTURE OF ESTERS AND KETALS OF A-KETOGLUTARIC ACID IS FORMED.
Claim 3
Dependent Claim
22 words
The process of claim 1 in which said acid catalyst is selected from the group consisting of sulfuric, phosphoric and perchloric acids.
Claim 4
Dependent Claim
19 words
The process of claim 1 in which said alcoholic solvent is methanol and said acid catalyst is sulfuric acid.
Claim 5
Dependent Claim
15 words
The process of claim 1 in which the electrolysis is carried out at about 15*-35*C.
Claim 6
Dependent Claim
48 words
-dialkoxy-process of claim 1 wherein following said electrolysis said solution is heated at from about 50* to 100*C. to substantially convert 2,5-dialkoxy-0b 2,5-dihydrofuran-2-carboxylate byproducts of said electrolysis to an additional amount of said mixture of delta -monoesters and diesters of Alpha -ketoglutaric acid and the corresponding ketals thereof.
Claim 7
Dependent Claim
43 words
The process of claim 5 wherein additional acid having a pKa less than about 2.5 is introduced to said solution prior to said heating to bring the total acid catalyst concentration within the range of from about 0.2 to 2.0 moles per liter.
References Cited (Backward Citations)
US2714576A
Cited
US3574072A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |