Patent US2676988A successfully refreshed from Google Patents.
US2676988A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making vitamin a and intermediates formed thereby
Assignee: Eastman Kodak Co
•
Filing: 1951-09-11
•
Granted: 1954-04-27
•
Expires: 1971-09-11
Abstract
No abstract record available.
Inventors
- 👤 Charles D Robeson
- 👤 Jacque K Lindsay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:13
CPC Classifications
C; C07; C07C; C07C403/00; C07C403/06; C07C403/08; C07C403/10; C07C403/14; C07C403/16; C07C2601/00; C07C2601/12; C07C2601/16
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
30 words
THE METHOD OF MAKING VITAMIN A WHICH COMPRISES, CONDENSING B-IONYLIDENE ACETALDEHYDE WITH A DIALKYL ACCETAL ACETAOCETALDEHYDE IN THE PRESENCE OF AN ALKOXIDE AND THEREBY FORMING A KEOACETAL OF THE FORMULA
References Cited (Backward Citations)
US2233375A
Cited
US2369157A
Cited
US2577538A
Cited
GB672936A
Cited
US2586305A
Cited
US2615922A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-04-26 | 1957-10-26 | 1958-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-04-26 | 1961-10-26 | 1962-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-04-26 | 1965-10-26 | 1966-04-27 | $7700.00 | Window Closed / Lapsed |