US2586837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparing dianisidine
Assignee: EIDP Inc
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Filing: 1950-09-28
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Granted: 1952-02-26
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Expires: 1970-09-28
Abstract
No abstract record available.
Inventors
- 👤 Adrian L Linch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:33
CPC Classifications
C; C07; C07C; C07C211/00; C07C211/43; C07C211/54
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
88 words
THE PROCESS FOR PREPARING SUBSTANTIALLY COLORLESS DIANISIDINE WHICH COMPRISES MIXING A DILUTE SOLUTION OF HYDRAZOANISOLE IN A MIXTURE OF TOLUENE AND ISOPROPANOL WITH A DILUTE AQEUOUS SOLUTION OF A STRONG NON-OXIDIZING MINERAL ACID HAVING DISSOLVED THEREIN FROM ABOUT 2% TO ABOUT 5% BY WEIGHT, BASED ON THE HYDRAZONANISOLE, OF AN ALKALI METAL SALT OF A DIALKYL DITHIOCARBAMIC ACID IN WHICH EACH ALKYL GROUP CONTAINS 1 TO 4 CARBON ATOMS, AGITATING THE MIXTURE UNTIL THE HYDRAZOANISOLE IS REARRANGED TO DIANISIDINE, AND THEN RECOVERING THE DIANISIDINE FROM THE REACTION MIXTURE.
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) | 1955-02-25 | 1955-08-27 | 1956-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-02-25 | 1959-08-27 | 1960-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-02-25 | 1963-08-27 | 1964-02-26 | $7700.00 | Window Closed / Lapsed |