US3208997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing purine and pyrimidine nucleosides
Assignee: Sankyo Co Ltd
•
Filing: 1963-11-08
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Granted: 1965-09-28
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Expires: 1983-11-08
Abstract
No abstract record available.
Inventors
- 👤 Iwai Issei
- 👤 Nishimura Takuzo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:36
CPC Classifications
C; C07; C07H; C07H19/00; C07H19/02; C07H19/04; C07H19/06; C07H19/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
16 words
A PROCESS FOR PREPARING A COMPOUND SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS HAVING THE FORMULAE
Claim 2
Dependent Claim
16 words
A PROCESS FOR PREPARING A COMPOUND SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS HAVING THE FORMULAE
References Cited (Backward Citations)
US2719843A
Cited
US2906756A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-09-27 | 1969-03-29 | 1969-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-27 | 1973-03-29 | 1973-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-27 | 1977-03-29 | 1977-09-28 | $7700.00 | Window Closed / Lapsed |