Patent US2704840A successfully refreshed from Google Patents.
US2987543A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resolution of dl-glutamic acid
Assignee: International Minerals and Chemical Corp
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Filing: 1958-05-27
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Granted: 1961-06-06
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Expires: 1978-05-27
Abstract
No abstract record available.
Inventors
- 👤 Joseph L Purvis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:06
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/487
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
195 words
A PROCESS FOR RESOLVING A DL-GLUTAMIC ACID COMPOUND SELECTED FROM THE GROUP CONSISTING OF DL-GLUTAMIC ACID, DL-GLUTAMIC ACID HYDROCHLORIDE, AND DL-GLUTAMIC ACID HYDROBROMIDE, WHICH COMPRISES ADDING SEED CRYSTALS OF SAID GLUTAMIC ACID COMPOUND IN ONE OF ITS OPTICALLY ACTIVE FORMS TO AN AQUEOUS SOLUTION CONTAINING SAID DL-GLUTAMIC ACID COMPOUND AT A SUPERSATURATION OF AT LEAST ABOUT 10%, BASED ON THE SATURATION LEVEL, THE PROPORTION OF SEED CRYSTALS BEING AT LEAST ABOUT 1% BY WEIGHT OF THE SEEDED ENANTIOMORPH IN THE SOLUTION IN THE CASE OF THE SAID DL-GLUTAMIC ACID HYDROHALIDES WHEREIN THE CORRESPONDING HYDROGEN HALIDE IS PRESENT IN FREE FORM, AND AT LEAST ABOUT 5% BY WEIGHT OF THE SEEDED ENANTIOMORPH IN THE SOLUTION IN THE CASE OF SOLUTIONS CONTAINING SAID DL-GLUTAMIC ACID COMPOUND WITHOUT FREE HYDROGEN HALIDE, CRYSTALLIZING SOLIDS FROM THE SOLUTION, SAID CRYSTALLIZED SOLIDS BEING INITIALLY SAID GLUTAMIC ACID COMPOUND OF OPTICAL ACTIVITY CORRESPONDING TO THE SEED CRYSTALS, AND SEPARATING THE CRYSTALLIZED SOLIDS FROM THE RESULTING SLURRY BEFORE SPONTANEOUS NUCLEATION AND CRYSTALLIZATION OF ANY SUBSTANTIAL PROPORTION OF THE NONSEEDED ENANTIOMORPH TAKES PLACE AND AT A POINT IN TIME NOT SUBSTANTIALLY LATER THAN THE ATTAINMENT OF THE MAXIMUM DEGREE OF RESOLUTION R, CALCULATED AS
Claim 2
Dependent Claim
195 words
A PROCESS FOR RESOLVING A DL-GLUTAMIC ACID COMPOUND SELECTED FROM THE GROUP CONSISTING OF DL-GLUTAMIC ACID, DL-GLUTAMIC ACID HYDROCHLORIDE, AND DL-GLUTAMIC ACID HYDROBROMIDE, WHICH COMPRISES ADDING SEED CRYSTALS OF SAID GLUTAMIC ACID COMPOUND IN ONE OF ITS OPTICALLY ACTIVE FORMS TO AN AQUEOUS SOLUTION CONTAINING SAID DL-GLUTAMIC ACID COMPOUND AT A SUPERSATURATION OF AT LEAST ABOUT 10%, BASED ON THE SATURATION LEVEL, THE PROPORTION OF SEED CRYSTALS BEING AT LEAST ABOUT 1% BY WEIGHT OF THE SEEDED ENANTIOMORPH IN THE SOLUTION IN THE CASE OF THE SAID DL-GLUTAMIC ACID HYDROHALIDES WHEREIN THE CORRESPONDING HYDROGEN HALIDE IS PRESENT IN FREE FORM, AND AT LEAST ABOUT 5% BY WEIGHT OF THE SEEDED ENANTIOMORPH IN THE SOLUTION IN THE CASE OF SOLUTIONS CONTAINING SAID DL-GLUTAMIC ACID COMPOUND WITHOUT FREE HYDROGEN HALIDE, CRYSTALLIZING SOLIDS FROM THE SOLUTION, SAID CRYSTALLIZED SOLIDS BEING INITIALLY SAID GLUTAMIC ACID COMPOUND OF OPTICAL ACTIVITY CORRESPONDING TO THE SEED CRYSTALS, AND SEPARATING THE CRYSTALLIZED SOLIDS FROM THE RESULTING SLURRY BEFORE SPONTANEOUS NUCLEATION AND CRYSTALLIZATION OF ANY SUBSTANTIAL PROPORTION OF THE NONSEEDED ENANTIOMORPH TAKES PLACE AND AT A POINT IN TIME NOT SUBSTANTIALLY LATER THAN THE ATTAINMENT OF THE MAXIMUM DEGREE OF RESOLUTION R, CALCULATED AS
References Cited (Backward Citations)
US2734919A
Cited
US2683739A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-06-05 | 1964-12-05 | 1965-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-05 | 1968-12-05 | 1969-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-05 | 1972-12-05 | 1973-06-06 | $7700.00 | Window Closed / Lapsed |