US2749345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pyrimidine compounds
Assignee: SmithKline Beecham Corp
•
Filing: 1953-01-02
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Granted: 1956-06-05
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Expires: 1973-01-02
Abstract
No abstract record available.
Inventors
- 👤 George H Hitchings
- 👤 Roland K Robins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:19
CPC Classifications
C; C07; C07D; C07D471/00; C07D471/02; C07D471/04
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
70 words
A METHOD OF PREPARING A 4-AMINOPYRIDO (2,3-D) PYRIMIDINE WHICH COMPRISES REACTING AN A-AMINONICOTINIC ACID WITH FORMAMIDE SUBSTANTIALLY IN EXCESS OF THE STOICHIOMETRIC AMOUNT AT A TEMPERATURE IN EXCESS OF 120* TO FORM A 4-HYDROXYPYRIDO (2,3-D) PYRIMIDINE, REACTING THIS COMPOUND WITH PHOSPHORYL OXYCHLORIDE, AND HEATING THE RESULTING DEVIRATIVE WITH AN AMINATING REAGENT SELECTED FROM THE CLASS CONSISTING OF AMMONIUM HYDROXIDE, ANILINE, HYDRAZINE HYDRATE, AND DIETHYLAMINE TO PRODUCE THE 4AMINOPYRIDO (2,3-D) PYRIMIDINE.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-06-05 | 1959-12-05 | 1960-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-06-05 | 1963-12-05 | 1964-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-06-05 | 1967-12-05 | 1968-06-05 | $7700.00 | Window Closed / Lapsed |