US2840559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclearly substituted 8-theophyllines and method of making the same
Assignee: KRANTZ JR
•
Filing: 1954-06-22
•
Granted: 1958-06-24
•
Expires: 1974-06-22
Abstract
No abstract record available.
Inventors
- 👤 Jr John C Krantz
- 👤 Raymond M Burgison
- 👤 George P Hager
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:53
CPC Classifications
C; C07; C07D; C07D473/00; C07D473/02; C07D473/04; C07D473/06; C07D473/08
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
5 words
COMPOUNDS HAVING THE GENERAL FORMULA:
References Cited (Backward Citations)
US955587A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-23 | 1961-12-23 | 1962-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-23 | 1965-12-23 | 1966-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-23 | 1969-12-23 | 1970-06-24 | $7700.00 | Window Closed / Lapsed |