Patent US2824876A successfully refreshed from Google Patents.
US2824876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of 4-mercaptonicotinic acid and intermediate therefor
Assignee: Schenley Industries Inc
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Filing: 1955-02-23
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Granted: 1958-02-25
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Expires: 1975-02-23
Abstract
No abstract record available.
Inventors
- 👤 Katz Leon
- 👤 Murray S Cohen
- 👤 Schroeder William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:38
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/60; C07D213/78; C07D213/79; C07D213/80; C07D213/86; C07D213/87; C07D213/88; C07D495/00; C07D495/02; C07D495/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
36 words
A PROCESS FOR THE PRODUCTION OF 4-MERCAPTONICOTINIC ACID WHICH COMPRISES THE REACTION OF 4-HYDROXYNICOTINIC ACID WITH PHOSPHORUS PENTASULFIDE TO FORM 5-AZA-1,2,3BENZODITHIOLE-3-THIONE, ALKALINE HYDROLYSIS OF THE RESULTING COMPOUND, AND SUBSEQUENT RE-RECOVERY OF 4-MERCAPTONICOTINIC ACID FROM THE HYDROLYZATE.
Claim 2
Dependent Claim
36 words
A PROCESS FOR THE PRODUCTION OF 4-MERCAPTONICOTINIC ACID WHICH COMPRISES THE REACTION OF 4-HYDROXYNICOTINIC ACID WITH PHOSPHORUS PENTASULFIDE TO FORM 5-AZA-1,2,3BENZODITHIOLE-3-THIONE, ALKALINE HYDROLYSIS OF THE RESULTING COMPOUND, AND SUBSEQUENT RE-RECOVERY OF 4-MERCAPTONICOTINIC ACID FROM THE HYDROLYZATE.
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) | 1961-02-24 | 1961-08-26 | 1962-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-02-24 | 1965-08-26 | 1966-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-02-24 | 1969-08-26 | 1970-02-25 | $7700.00 | Window Closed / Lapsed |