US3919264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of anthraquinone from dihydroanthracene
Assignee: Beazer East Inc
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Filing: 1974-10-29
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Granted: 1975-11-11
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Expires: 1994-10-29
Abstract
Abstract A mixture of nitric acid and dihydroanthracene that is dissolved in an inert solvent is maintained at elevated temperatures with agitation until the dihydroanthracene is oxidized to anthraquinone. The anthraquinone is thereafter separated from the reaction mass.
Inventors
- 👤 Nicholas P Greco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:43
CPC Classifications
C; C07; C07C; C07C46/00; C07C46/02; C07C201/00; C07C201/06; C07C201/08; C07C205/00; C07C205/06; C07C50/00; C07C2603/00; C07C2603/02; C07C2603/04; C07C2603/22; C07C2603/24
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
133 words
A PROCESS FOR THE PRODUCTION OF ANTHRAQUIONE OF HIGH PURITY WHICH COMPRISES: A. ADDING TO A MIXING ZONE AT A TEMPERATURE BELOW REFUX TEMPERATURE: I. A SOLUTION OF DIHYDROANTHRACENE HAVING A PURITY OF AT LEAST 90% IN A SOLVENT THAT IS INERT TO NITRIC ACID, AND II. AQUEOUS NITRIC ACID HAVING A CONCENTRATION OF 45 - 70% AND WHEREIN THE NITRIC ACID IS IN EXCESS OF THE STOCIHIOMETRIC AMOUNT THAT IS NECESSARY TO CONVERT THE DIHYDROANTHRACENE TO ANTHRAQUIONE, B. MAINTAINING THE RESULTANT MIXTURE UNDER AGITATION AND AT A TEMPERATURE OF ABOUT THE REFLUX TEMPERATURE OF SAID RESULTANT MIXTURE FOR A PERIOD OF TIME SUFFICIENT TO CONVERT THE DIHYDROANTHACENE TO ANTHRANCENE TO ANTHRAQUIONE, AND C. COOLING THE MIXTURE WHEREUPON THE ANTHRAQUINONE BECOMES SOLIDS, AND D. THEREAFTER SEPARATING THE ANTHRAQUINONE SOLIDS FROM THE REACTION MIXTURE.
Claim 2
Dependent Claim
133 words
A PROCESS FOR THE PRODUCTION OF ANTHRAQUIONE OF HIGH PURITY WHICH COMPRISES: A. ADDING TO A MIXING ZONE AT A TEMPERATURE BELOW REFUX TEMPERATURE: I. A SOLUTION OF DIHYDROANTHRACENE HAVING A PURITY OF AT LEAST 90% IN A SOLVENT THAT IS INERT TO NITRIC ACID, AND II. AQUEOUS NITRIC ACID HAVING A CONCENTRATION OF 45 - 70% AND WHEREIN THE NITRIC ACID IS IN EXCESS OF THE STOCIHIOMETRIC AMOUNT THAT IS NECESSARY TO CONVERT THE DIHYDROANTHRACENE TO ANTHRAQUIONE, B. MAINTAINING THE RESULTANT MIXTURE UNDER AGITATION AND AT A TEMPERATURE OF ABOUT THE REFLUX TEMPERATURE OF SAID RESULTANT MIXTURE FOR A PERIOD OF TIME SUFFICIENT TO CONVERT THE DIHYDROANTHACENE TO ANTHRANCENE TO ANTHRAQUIONE, AND C. COOLING THE MIXTURE WHEREUPON THE ANTHRAQUINONE BECOMES SOLIDS, AND D. THEREAFTER SEPARATING THE ANTHRAQUINONE SOLIDS FROM THE REACTION MIXTURE.
Claim 3
Dependent Claim
25 words
The process of claim 1 wherein said solvent is selected from the class consisting of perchloroethylene, bromobenzene, chlorobenzene, 1,2-dibromobenzene, 1,3-dibromobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, m-bromochlorobenzene, and 1,2-4-trichlorobenzene.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein the dihydroanthracene constitutes about 30% of the total weight of said solution.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein 4.5 moles of nitric acid per mole of dihydroanthracene are used.
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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |