US3681403A
Expired / Lapsed
US
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Process for the production of 2,5-diamino-3,6-dihalogeno-p-benzoquinones
Assignee: Novartis AG
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Filing: 1968-07-26
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Granted: 1972-08-01
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Expires: 1988-07-26
Abstract
Abstract 2,5-DIAMINO-3,6-DIHALOGENO-P-BENZOQUINONES ARE PRODUCED IN UNEXPECTEDLY HIGH YIELD RATES AND EXCELLENT PURITY FROM TETRAHALOGENATED P-BENZOQUINONES BY REACTION WITH AMMONIA IN A REACTION MEDIUM CONSISTING OF AN APROTIC DIPOLAR ORGANIC SOLVENT HAVING A DIELECTRIC CONSTANT OF AT LEAST 30 AT 25*C.
Inventors
- 👤 Tibor Somlo
- 👤 Ivan Orban
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:07
CPC Classifications
C; C07; C07C; C07C233/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
27 words
A process as defined in claim 1, wherein the molar ratio of said starting benzoquinone to ammonia is in the range of from 1:4 to about 1:4.8.
Claim 2
Dependent Claim
38 words
A process as defined in claim 2, wherein the temperature of the reaction mixture is at least -10* C and is such that the solubility of ammonia in said solvent is at least about 5 g per liter.
Claim 3
Dependent Claim
20 words
A process as defined in claim 1, wherein the temperature of the reaction mixture is held between -10*C and +100*C.
Claim 4
Dependent Claim
21 words
A process as defined in claim 1, wherein the temperature of the reaction mixture is held between about +20*C and +50*C.
Claim 5
Dependent Claim
31 words
A process as defined in claim 3, wherein ammonia is introduced at a rate of at most 0.5 g per minute into a mixture of said starting benzoquinone and said solvent.
Claim 6
Dependent Claim
33 words
A process as defined in claim 3, wherein the aprotic solvent is selected from dimethyl formamide, dimethyl acetamide, dimethyl sulphoxide, tetramethylene sulphone, acetonitrile, nitrobenzene, N-methylpyrrolidone and mixtures of these solvents with each other.
Claim 7
Dependent Claim
23 words
A process as defined in claim 1, wherein the two Hal in formulas I and II represent two chlorine or two bromine atoms.
References Cited (Backward Citations)
US3037015A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |