US2783278A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of omicion-nitrodiphenylamine
Assignee: Wyeth Holdings LLC
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Filing: 1954-04-20
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Granted: 1957-02-26
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Expires: 1974-04-20
Abstract
No abstract record available.
Inventors
- 👤 Thelin Jack Horstmann
- 👤 Cherlow Herman
- 👤 Megson Frederic Houghton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:21
CPC Classifications
C; C07; C07C; C07C211/00; C07C211/43; C07C211/54; C07C209/00; C07C209/30; C07C209/32; C07C209/36
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
THE METHOD OF PURIFYING O-NITRODIPHENYLAMINE WHICH COMPRISES CONTACTING, AT A TEMPERATURE NOT IN EXCESS OF 80*C., A SOLID MIXTURE COMPRISING O-NITRODIPHENYLAMINE CONTAMINATED WITH PHENAZINE WITH AN AQUEOUS SOLUTION OF AN ACID SELECTED FROM THE GROUP CONSISTING OF SULFURIC, HYDROCHLORIC, PHOSPHORIC, HYDROBROMIC, ACETIC, CHLOROACETIC, TRICHLOROACETIC, FORMIC, AND PROPIONIC ACIDS, THE TEMPERATURE AND ACID STRENGTH BEING SUCH THAT A WATER SOLUBLE SALT OF PHENAZINE WITH SAID ACID IS FORMED, AND THAT A WATER-SOLUBLE SALT OF O-NITRODIPHENYLAMINE IS NOT FORMED, AND SEPARATING THE PURIFIED SOLID O-NITRODIPHENYLAMINE FROM THE SOLUTION CONTAINING THE SALT OF PHENAZINE.
Claim 2
Independent Claim
91 words
THE METHOD OF PURIFYING O-NITRODIPHENYLAMINE WHICH COMPRISES CONTACTING, AT A TEMPERATURE NOT IN EXCESS OF 80*C., A SOLID MIXTURE COMPRISING O-NITRODIPHENYLAMINE CONTAMINATED WITH PHENAZINE WITH AN AQUEOUS SOLUTION OF AN ACID SELECTED FROM THE GROUP CONSISTING OF SULFURIC, HYDROCHLORIC, PHOSPHORIC, HYDROBROMIC, ACETIC, CHLOROACETIC, TRICHLOROACETIC, FORMIC, AND PROPIONIC ACIDS, THE TEMPERATURE AND ACID STRENGTH BEING SUCH THAT A WATER SOLUBLE SALT OF PHENAZINE WITH SAID ACID IS FORMED, AND THAT A WATER-SOLUBLE SALT OF O-NITRODIPHENYLAMINE IS NOT FORMED, AND SEPARATING THE PURIFIED SOLID O-NITRODIPHENYLAMINE FROM THE SOLUTION CONTAINING THE SALT OF PHENAZINE.
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) | 1960-02-26 | 1960-08-27 | 1961-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-02-26 | 1964-08-27 | 1965-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-02-26 | 1968-08-27 | 1969-02-26 | $7700.00 | Window Closed / Lapsed |