Patent US3159652A successfully refreshed from Google Patents.
US3159652A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of gamma-pyrones
Assignee: Pfizer Inc
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Filing: 1962-06-13
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Granted: 1964-12-01
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Expires: 1982-06-13
Abstract
No abstract record available.
Inventors
- 👤 Bryce E Tate
- 👤 Robert P Allingham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:34
CPC Classifications
C; C07; C07D; C07D309/00; C07D309/34; C07D309/36; C07D309/40
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
57 words
A PROCESS FOR THE PREPARATION OF MALTOI WHICH COMPRISES TREATING KOJIC ACID WITH FORMALDEHYDE AND A REAGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL HYDROXIDES, DI-LOWER ALKYLAMINES, SAID ALKYL RADICALS EACH CONTAINING UP TO ABOUT FOUR CARBON ATOMS, PIPERIDINE AND MORPHOLINE AT A PH OF AT LEAST ABOUT 5 TO FORM A COMPOUND OF THE FORMULA
Claim 2
Dependent Claim
57 words
A PROCESS FOR THE PREPARATION OF MALTOI WHICH COMPRISES TREATING KOJIC ACID WITH FORMALDEHYDE AND A REAGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL HYDROXIDES, DI-LOWER ALKYLAMINES, SAID ALKYL RADICALS EACH CONTAINING UP TO ABOUT FOUR CARBON ATOMS, PIPERIDINE AND MORPHOLINE AT A PH OF AT LEAST ABOUT 5 TO FORM A COMPOUND OF THE FORMULA
Claim 3
Dependent Claim
5 words
A COMPOUND OF THE FORMULA
Claim 4
Dependent Claim
5 words
A COMPOUND OF THE FORMULA
References Cited (Backward Citations)
US2907773A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-12-01 | 1968-06-01 | 1968-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-12-01 | 1972-06-01 | 1972-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-12-01 | 1976-06-01 | 1976-12-01 | $7700.00 | Window Closed / Lapsed |