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US4154747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of virtually pure 1-amino-8-nitro-4,5-dihydroxyanthraquinone
Assignee: BASF SE
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Filing: 1978-06-20
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Granted: 1979-05-15
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Expires: 1998-06-20
Abstract
Abstract A process for the preparation of 1-amino-8-nitro-4,5-dihydroxyanthraquinone by partially reducing the corresponding dinitrohydroxyanthraquinone and isolating the reduction product, in which crude 1,8-dinitro-4,5-dihydroxyanthraquinone obtained by nitrating 4,5-dihydroxyanthraquinone is partially reduced in a phenol-water mixture, which contains from 5 to 50% by weight of water, in the presence of an alkali metal phenolate, by means of a reductone, reductonate or a mixture of these. The product is virtually free from by-products and is suitable for use for the synthesis of dyes.
Inventors
- 👤 Gerhard Epple
- 👤 Wolfgang Elser
- 👤 Walter Himmele
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:59
CPC Classifications
C; C07; C07C; C07C221/00; C07C2603/00; C07C2603/02; C07C2603/04; C07C2603/22; C07C2603/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
78 words
In a process for the production of virtually pure 1-amino-8-nitro-4,5-dihydroxyanthraquinone by partially reducing 1,8-dinitro-4,5-dihydroxyanthraquinone in an aqueous medium and isolating the resultant 1-amino-8-nitro-4,5-dihydroxyanthraquinone, the improvement wherein crude 1,8-dinitro-4,5-dihydroxyanthraquinone obtained by nitration of 4,5-dihydroxyanthraquinone is partially reduced in a phenol-water mixture, which contains from 5 to 50% by weight of water, in the presence of an alkali metal phenolate by means of a reducing agent selected from the group consisting of a reductone, a reductonate and a mixture thereof.
Claim 2
Dependent Claim
78 words
In a process for the production of virtually pure 1-amino-8-nitro-4,5-dihydroxyanthraquinone by partially reducing 1,8-dinitro-4,5-dihydroxyanthraquinone in an aqueous medium and isolating the resultant 1-amino-8-nitro-4,5-dihydroxyanthraquinone, the improvement wherein crude 1,8-dinitro-4,5-dihydroxyanthraquinone obtained by nitration of 4,5-dihydroxyanthraquinone is partially reduced in a phenol-water mixture, which contains from 5 to 50% by weight of water, in the presence of an alkali metal phenolate by means of a reducing agent selected from the group consisting of a reductone, a reductonate and a mixture thereof.
Claim 3
Dependent Claim
18 words
A process as claimed in claim 1, wherein hydroxyacetone, dihydroxyacetone or glucose is used as the reducing agent.
Claim 4
Dependent Claim
20 words
A process as claimed in claim 1, wherein the reduction is carried out at from 20° C. to 100° C.
Claim 5
Dependent Claim
19 words
A process as claimed in claim 1, wherein the reduction is carried out at from 80° to 100° C.
Claim 6
Dependent Claim
31 words
A process as claimed in claim 1, wherein the reduction is carried out in the presence of from 0.2 to 1.5 moles of an alkali metal phenolate per mole of dinitro-dihydroxyanthraquinone.
Claim 7
Dependent Claim
27 words
A process as claimed in claim 1, wherein the reduction is carried out in a phenol-water mixture which contains from 30 to 45% by weight of water.
Claim 8
Dependent Claim
24 words
A process as claimed in claim 2, wherein the amount of reducing agent used is such that no 1,8-dinitro-4,5-dihydroxyanthraquinone remains in the reaction mixture.
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) | 1982-05-14 | 1982-11-13 | 1983-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-14 | 1986-11-13 | 1987-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-14 | 1990-11-13 | 1991-05-15 | $7700.00 | Window Closed / Lapsed |