Patent US3965129A successfully refreshed from Google Patents.
US3965129A
Expired / Lapsed
US
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Optical resolution of organic carboxylic acids
Assignee: Hoffmann La Roche Inc
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Filing: 1975-05-15
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Granted: 1976-06-22
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Expires: 1995-05-15
Abstract
Abstract Racemic organic carboxylic acids are efficiently resolved into their enantiomers with antipodes of α-methyl-p-nitrobenzylamine.
Inventors
- 👤 Clark William Perry
- 👤 Sidney Teitel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:15
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/26; C07D307/30; C07D307/32; C07D307/33; C07D209/00; C07D209/02; C07D209/04; C07D209/10; C07D209/18; C07D209/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
4 words
(+)-threo-Epoxyaconitic acid bis-R(+)-α-methyl-p-nitrobenzylamine salt.
Claim 2
Dependent Claim
4 words
(+)-threo-Epoxyaconitic acid bis-R(+)-α-methyl-p-nitrobenzylamine salt.
References Cited (Backward Citations)
US3810931A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-22 | 1979-12-22 | 1980-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-22 | 1983-12-22 | 1984-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-22 | 1987-12-22 | 1988-06-22 | $7700.00 | Window Closed / Lapsed |