US3963762A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone
Assignee: Bayer AG
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Filing: 1974-10-10
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Granted: 1976-06-15
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Expires: 1994-10-10
Abstract
Abstract Substantially pure 1,5- and/or 1,8-dinitroanthraquinone is recovered from dinitration mixtures which may contain sulfuric acid or a perfluoralkane sulfonic acid by adjusting the nitric acid concentration in the nitration mixture to a value of 91 to 96% for a ratio by weight of nitric acid to solids of from 2.5 : 1 to 10 : 1; separating off the insoluble crude 1,5-dinitroanthranthraquinone at 15° to 50°C; taking up the 1,5-dinitroanthraquinone with 90 to 100% nitric acid in a ratio by weight of nitric acid to solids of from 0.5 : 1 to 3.5 : 1; stirring at 15° to 80° C; separating off the insoluble pure 1,5-dinitroanthraquinone thus obtained; adjusting the mother liquid left following separation of the crude 1,5-dinitroanthraquinone to a nitric acid concentration of from 88 to 94% for a ratio by weight of nitric acid to solids of from 3.0 : 1 to 12 : 1, with the proviso that the nitric acid concentration is at least 1.5% lower than in the preceding separation of crude 1,5-dinitroanthraquinone; and separating off the pure 1,8-dinitroanthraquinone obtained in this way at a temperature in the range of from 20° to 50°C and freeing it from the nitric acid adhering thereto.
Inventors
- 👤 Walter Hohmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:08
CPC Classifications
C; C07; C07C; C07C201/00; C07C201/06; C07C201/08; C07C201/16
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
206 words
Process for recovering substantially pure 1,5-and/or 1,8-dinitroanthraquinone from dinitration mixtures optionally containing sulphuric acid or a perfluoralkane sulphonic acid which comprises i. adjusting the nitric acid concentration in the nitration mixture to a value of 91 to 96% for a ratio by weight of nitric acid to solids of from 2.5 : 1 to 10 : 1; ii. separating off the insoluble crude 1,5-dinitroanthraquinone at 15° to 50°C; iii. taking up the 1,5-dinitroanthraquinone with 90 to 100% nitric acid in a ratio by weight of nitric acid to solids of from 0.5 : 1 to 3.5 : 1; iv. stirring at 15° to 80°C; v. separating off the insoluble pure 1,5-dinitroanthraquinone thus obtained; vi. adjusting the mother liquid left following separation of the crude 1,5-dinitroanthraquinone to a nitric acid concentration of from 88 to 94% for a ratio by weight of nitric acid to solids of from 3.0 : 1 to 12 : 1, with the proviso that the nitric acid concentration is at least 1.5% lower than in the preceding separation of crude 1,5-dinitroanthraquinone; and vii. separating off the pure 1,8-dinitroanthraquinone obtained in this way at a temperature in the range of from 20° to 50°C and freeing it from the nitric acid adhering thereto.
Claim 2
Dependent Claim
206 words
Process for recovering substantially pure 1,5-and/or 1,8-dinitroanthraquinone from dinitration mixtures optionally containing sulphuric acid or a perfluoralkane sulphonic acid which comprises i. adjusting the nitric acid concentration in the nitration mixture to a value of 91 to 96% for a ratio by weight of nitric acid to solids of from 2.5 : 1 to 10 : 1; ii. separating off the insoluble crude 1,5-dinitroanthraquinone at 15° to 50°C; iii. taking up the 1,5-dinitroanthraquinone with 90 to 100% nitric acid in a ratio by weight of nitric acid to solids of from 0.5 : 1 to 3.5 : 1; iv. stirring at 15° to 80°C; v. separating off the insoluble pure 1,5-dinitroanthraquinone thus obtained; vi. adjusting the mother liquid left following separation of the crude 1,5-dinitroanthraquinone to a nitric acid concentration of from 88 to 94% for a ratio by weight of nitric acid to solids of from 3.0 : 1 to 12 : 1, with the proviso that the nitric acid concentration is at least 1.5% lower than in the preceding separation of crude 1,5-dinitroanthraquinone; and vii. separating off the pure 1,8-dinitroanthraquinone obtained in this way at a temperature in the range of from 20° to 50°C and freeing it from the nitric acid adhering thereto.
Claim 3
Dependent Claim
25 words
Process of claim 1 wherein the pure 1,5-dinitroanthraquinone is washed with 95 to 100% nitric acid, and then freed from the nitric acid adhering thereto.
Claim 4
Dependent Claim
78 words
Process of claim 1 wherein an nitric acid concentration of from 92.5 to 95.5% is adjusted in the separation of the 1,5-dinitroanthraquinone for a ratio by weight of nitric acid to solids of from 2.5 : 1 to 10 : 1, while a nitric acid concentration of from 88 to 92.5 is adjusted in the separation of the 1,8-dinitroanthraquinone for a ratio by weight of nitric acid to solids of from 3.5 : 1 to 10 : 1.
Claim 5
Dependent Claim
78 words
Process of claim 1 wherein a nitric acid concentration of from 94 to 96% is adjusted in the separation of the 1,5-dinitroanthraquinone for a ratio by weight of nitric acid to solids of from 5.5 : 1 to 3.5 : 1, while a nitric acid concentration of from 91 to 93% is adjusted in the separation of the 1,8-dinitroanthraquinone for a ratio by weight of nitric acid to solids of from 7 : 1 to 3.5 : 1.
Claim 6
Dependent Claim
78 words
Process of claim 1 wherein a nitric acid concentration of from 91 to 93% is adjusted in the separation of the 1,5-dinitroanthraquinone for a ratio by weight of nitric acid to solids of from 9.5 : 1 to 6.5 : 1, while a nitric acid concentration of from 88 to 91% is adjusted in the separation of the 1,8-dinioanthraquinone for a ratio by weight of nitric acid to solids of from 12 : 1 to 7 : 1.
Claim 7
Dependent Claim
20 words
Process of claim 1 wherein separation is carried out at a temperature in the range of from 20° to 35°C.
Claim 8
Dependent Claim
21 words
Process of claim 1 wherein in the separation of 1,8-dinitroanthraquinone the nitric acid concentration is adjusted by distilling off nitric acid.
Claim 9
Dependent Claim
19 words
Process of claim 1 wherein in the separation of 1,8-dinitroanthraquinone the nitric acid concentration is adjusted by adding water.
Claim 10
Dependent Claim
31 words
Process of claim 1 wherein in the separation of 1,8-dinitroanthraquinone the concentration of nitric acid is adjusted by the addition of aqueous nitric acid with a concentration of at least 65%.
Claim 11
Dependent Claim
25 words
Process of claim 1 wherein the dinitration mixture is obtained by nitrating anthraquinone and/or 1-nitroanthraquinone with nitric acid with a concentration of 94 to 100%.
Claim 12
Dependent Claim
27 words
Process of claim 10 wherein the concentrated nitric acid containing 1,5- and 1,8-dinitroanthraquinone left following separation of the pure 1,5-dinitroanthraquinone is reused for the dinitration of anthraquinone.
Claim 13
Dependent Claim
36 words
Process of claim 1 wherein the required nitric acid concentration is adjusted in the reaction mixture by distilling off concentrated nitric acid, by adding water or aqueous nitric acid or by a combination of these measures.
Claim 14
Dependent Claim
28 words
Process of claim 10 wherein the mixture of 1,5- and 1,8-dinitroanthraquinone isolated from the mother liquor left after separation of the 1,8-dinitroanthraquinone is returned to the nitration stage.
Claim 15
Dependent Claim
78 words
Process of claim 1 wherein in cases where 1,8-dinitroanthraquinone alone is separated off without previous separation of crude 1,5-dinitroanthraquinone, the dinitration mixture used contains less than 15% of 1,5-dinitroanthraquinone, and separation of the 1,8-dinitroanthraquinone is carried out with a ratio by weight of nitric acid to solids of from 3.5 : 1 to 10 : 1, with a nitric acid concentration of from 88 to 92.5% and at a temperature in the range of from 20° to 50°C.
Claim 16
Dependent Claim
14 words
Process of claim 14 wherein the dinitration mixture contains less than 10% of 1,5-dinitroanthraquinone.
Claim 17
Dependent Claim
20 words
Process of claim 14 wherein separation of the 1,8-dinitroanthraquinone is carried out at a temperature of from 25° to 35°C.
References Cited (Backward Citations)
US3818052A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |