US3937719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
(4-oxo-4h-1-benzopyran-2-yl)-oxamic acid, salts and esters anti-allergic agents
Assignee: Wyeth LLC
•
Filing: 1975-01-06
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Granted: 1976-02-10
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Expires: 1995-01-06
Abstract
Abstract Anti-allergic agents present the following structural formula: ##SPC1## In which R is --H, lower alkyl or an alkali metal cation. R 2 is alkyl of 1 to 6 carbon atoms or hydroxyalkyl of 2 to 6 carbon atoms.
Inventors
- 👤 John H. Sellstedt
- 👤 Dieter H. Klaubert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:31
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/04; C07D311/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
42 words
A compound of the formula ##SPC3## in which R is --H, alkyl of 1 to 6 carbon atoms or an alkali metal cation and R 2 is alkyl of 1 to 6 carbon atoms or hydroxyalkyl of 2 to 6 carbon atoms.
Claim 2
Dependent Claim
42 words
A compound of the formula ##SPC3## in which R is --H, alkyl of 1 to 6 carbon atoms or an alkali metal cation and R 2 is alkyl of 1 to 6 carbon atoms or hydroxyalkyl of 2 to 6 carbon atoms.
Claim 3
Dependent Claim
8 words
The compound of claim 1 which is ##SPC4##
Claim 4
Dependent Claim
8 words
The compound of claim 1 which is ##SPC5##
Claim 5
Dependent Claim
8 words
The compound of claim 1 which is ##SPC6##
Claim 6
Dependent Claim
8 words
The compound of claim 1 which is ##SPC7##
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) | 1979-02-09 | 1979-08-11 | 1980-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-09 | 1983-08-11 | 1984-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-09 | 1987-08-11 | 1988-02-10 | $7700.00 | Window Closed / Lapsed |