Claims
- 1. Process for the preparation of 1-nitro-anthraquinone with yields of about 74 to 80% relative anthraquinone employed, by the mononitration of anthraquinone with nitric acid/sulphuric acid mixtures, which consists of nitrating anthraquinone in a nitric acid/sulphuric acid mixture in a two phase system consisting of a liquid organic phase and a liquid inorganic phase, in which the weight ratio of nitric acid to sulphuric acid is about 1:1 to about 2:1, in which the weight ratio of sulphuric acid to anthraquinone is about 0.5:1 to about 1:1 and in which the weight ratio of sulphuric acid to water is about 2.5:1 to about 5.1:1, the weight ratios relating to the sum of the materials employed, the nitric acid being employed in a concentration of about 90 to 100% by weight and the sulfuric acid being employed in a concentration of about 70 to 85% by weight at temperatures in the range from about 45.degree. to 70.degree. C. until the anthraquinone content is less than 3% by weight, relative to the sum of the anthraquinone compounds.
- 2. Process of claim 1, wherein the nitration is carried out at temperatures in the range from about 48.degree. to 60.degree. C.
- 3. Process of claim 1, wherein the nitration in the initial phase of the nitration is carried out at temperatures in the range from about 45.degree. to 55.degree. C. and after over 50% of the anthraquinone employed are mononitrated the temperature is increased to about 55.degree. to 70.degree. C.
- 4. Process of claim 1, wherein the nitration is carried out in a nitric acid/sulphuric acid mixture in which the weight ratio of nitric acid to sulphuric acid is about 1.2:1 to 1.5:1.
- 5. Process of claim 1, wherein the nitration is carried out in a nitric acid/sulphuric acid mixture in which the weight ratio of sulphuric acid to anthraquinone is about 0.6:1 to 0.8:1.
- 6. Process of claim 1, wherein the weight ratio of sulphuric acid to water is about 3.5:1 to 5.3:1.
- 7. Process of claim 1, wherein the entire nitric acid/sulphuric acid mixture is initially introduced and the anthraquinone is introduced into this.
- 8. Process of claim 1, wherein the nitric acid/sulphuric acid mixture and the anthraquinone are metered separately but synchronously into a mixture in which the reaction has completely or partially ended.
- 9. Process of claim 1, wherein the process is carried out in a multi-stage reaction cascade and the metering-in of the nitric acid/sulphuric acid mixture and of the anthraquinone is carried out synchronously in a continuous process into the first element of the reaction cascade.
- 10. Process of claim 1, wherein the metering-in of the nitric acid/sulphuric acid mixture and of the anthraquinone is carried out in a continuous process into a reaction tube.
- 11. Process of claim 1, wherein the weight ratios indicated are set up by initially introducing a portion of the sulphuric acid, of the water and of the anthraquinone, adding a portion of the nitric acid until an emulsion of a predominantly liquid organic phase and an inorganic phase (H.sub.2 SO.sub.4 /HNO.sub.3) forms and only then adding the remainder of the anthraquinone, of the nitric acid, of the water and, if appropriate, of the H.sub.2 SO.sub.4.
- 12. Process according to claim 11, wherein in the initial mixture the ratio H.sub.2 SO.sub.4 /anthraquinone is >1 and the ratio H.sub.2 SO.sub.4 /H.sub.2 O is <3.6.
- 13. Process according to claim 11, wherein the remaining anthraquinone is added synchronously with or faster than the nitric acid and sulphuric acid.
Priority Claims (1)
Number |
Date |
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2646649 |
Oct 1976 |
DEX |
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Parent Case Info
This is a continuation of application Ser. No. 835,938, filed Sept. 22, 1977 now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4012426 |
Toth |
Mar 1977 |
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Foreign Referenced Citations (1)
Number |
Date |
Country |
50-50352 |
May 1975 |
JPX |
Non-Patent Literature Citations (2)
Entry |
Okada, Tsugio et al., "1-Nitroanthraquinone" in Chemical Abstract No. 178651q, vol. 83, 1975, p. 536. |
Stoeckelmann, Guenter et al., "1-Nitroanthraquinone by Continuous Nitration of Anthraquinone" in Chemical Abstract No. 115,367y, 7/1973, 94144(e), vol. 85, 1976. |
Continuations (1)
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Parent |
835938 |
Sep 1977 |
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