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US2942004A
Expired / Lapsed
US
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Resolution of 5, 5-phenylethylhydantoin
Assignee: Monsanto Chemicals Ltd
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Filing: 1956-05-09
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Granted: 1960-06-21
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Expires: 1976-05-09
Abstract
No abstract record available.
Inventors
- 👤 William T Cave
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:47
CPC Classifications
C; C07; C07D; C07D233/00; C07D233/54; C07D233/66; C07D233/72; C07D233/74
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
109 words
THE METHOD OF RESOLVING A RACEMIC MIXTURE OF 5,5-PHENYLETHYLHYDANTOIN ENANTIOMORPHS WHICH COMPRISES CAUSING THE LEVO-FORM TO CRYSTALLIZE FROM AN ALCOHOLIC SOLUTION COMPRISING 0.1 TO 1 GRAM OF RACEMIC MIXTURE AND 0.01 TO 0.2 GRAM OF LEVO-FROM PER 10 ML. ALCOHOL, AT A TEMPERATURE OF 10* TO 30*C. AND SEPARATING THE RESULTING CRYSTALS FROM THE SOLUTION BEFORE EQUILIBRIUM IS ATTAINED AND WITHIN 20 TO 40 MINUTES, THE TOTAL AMOUNT OF 5,5-PHENYLETHYLHYDANTOIN IN THE SAID ALCOHOLIC SOLUTION BEING ABOVE THE MAXIMUM SUPERSATURATION AMOUNT, BUT NOT MORE THAN 1.3 TIMES ABOVE AND THE AMOUNT OF LEVO-FORM BEING LESS THAN 1.3 TIMES ABOVE AND SAID FORM WHICH WILL CRYSTALLIZE IN THE CRYSTALLIZATION TIME.
Claim 2
Independent Claim
109 words
THE METHOD OF RESOLVING A RACEMIC MIXTURE OF 5,5-PHENYLETHYLHYDANTOIN ENANTIOMORPHS WHICH COMPRISES CAUSING THE LEVO-FORM TO CRYSTALLIZE FROM AN ALCOHOLIC SOLUTION COMPRISING 0.1 TO 1 GRAM OF RACEMIC MIXTURE AND 0.01 TO 0.2 GRAM OF LEVO-FROM PER 10 ML. ALCOHOL, AT A TEMPERATURE OF 10* TO 30*C. AND SEPARATING THE RESULTING CRYSTALS FROM THE SOLUTION BEFORE EQUILIBRIUM IS ATTAINED AND WITHIN 20 TO 40 MINUTES, THE TOTAL AMOUNT OF 5,5-PHENYLETHYLHYDANTOIN IN THE SAID ALCOHOLIC SOLUTION BEING ABOVE THE MAXIMUM SUPERSATURATION AMOUNT, BUT NOT MORE THAN 1.3 TIMES ABOVE AND THE AMOUNT OF LEVO-FORM BEING LESS THAN 1.3 TIMES ABOVE AND SAID FORM WHICH WILL CRYSTALLIZE IN THE CRYSTALLIZATION TIME.
References Cited (Backward Citations)
US1861458A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-06-21 | 1963-12-21 | 1964-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-06-21 | 1967-12-21 | 1968-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-06-21 | 1971-12-21 | 1972-06-21 | $7700.00 | Window Closed / Lapsed |