US2844576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of purines
Assignee: Wyeth Holdings LLC
•
Filing: 1955-11-22
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Granted: 1958-07-22
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Expires: 1975-11-22
Abstract
No abstract record available.
Inventors
- 👤 Goldman Leon
- 👤 Joseph W Marsico
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:12
CPC Classifications
C; C07; C07D; C07D473/00; C07D473/02; C07D473/24; C07D473/18; C07D473/22; C07D473/40
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
8 words
THE METHOD OF PREPARING PURINES OF THE FORMULA:
Claim 2
Independent Claim
8 words
THE METHOD OF PREPARING PURINES OF THE FORMULA:
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-07-21 | 1962-01-20 | 1962-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-07-21 | 1966-01-20 | 1966-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-07-21 | 1970-01-20 | 1970-07-22 | $7700.00 | Window Closed / Lapsed |