Method for closed-ring synthesizing anthraquinone from o-benzoylbenzoic acid

A technology of o-benzoylbenzoic acid and benzoylbenzoic acid, which is applied in the field of anthraquinone synthesis, can solve the problems of increased waste disposal cost, large amount of sulfuric acid used, and high production cost, and can save time for heating, Eliminate the process of heating up, and the effect of fineness is good

Inactive Publication Date: 2005-10-19
赵振国
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this process, the use of sulfuric acid is large, which not only leads to high production costs, but also produces a relatively large amount of waste su

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0012] Example 1:

[0013] Take 1000 kg of commercially available phthaloyl benzoic acid containing 10% water and put it into a closed-loop reactor, stir and heat up to 140° C., and keep it for 25 minutes to evaporate the water on the surface of phthaloyl benzoic acid. Reduce the temperature to 125°C, then add SO 3 1620 kg of oleum with a content of 17% (1.8 times the dry weight of phthaloyl benzoic acid). After the addition, the reaction exotherm caused the temperature to rise to 178°C, followed by the ring-closure reaction for 1 hour. The obtained product is subjected to conventional isolation, filtration, water treatment, drying and other steps to obtain 738.4 kg of dry anthraquinone with a light yellow color and a content of 99.05%.

Example Embodiment

[0014] Example 2:

[0015] Take 1000 kg of commercially available phthaloyl benzoic acid containing 10% water and put it into a closed-loop reactor, stir and heat up to 140° C., and keep it for 25 minutes to evaporate the water on the surface of phthaloyl benzoic acid. Reduce the temperature to 125°C, then add SO 3 1350 kg of oleum with a content of 22% (1.5 times the dry weight of phthaloyl benzoic acid). After the addition, the temperature was raised to 179°C, and then the ring-closure reaction was carried out for 1 hour. After conventional separation, filtration, water treatment, drying and other process steps, 778.8 kg of dry anthraquinone with light yellow color and 99.07% content can be obtained.

Example Embodiment

[0016] Example 3:

[0017] Take 1000 kg of commercially available phthaloyl benzoic acid containing 10% water and put it into a closed-loop reactor, stir and heat up to 140° C., and keep it for 25 minutes to evaporate the water on the surface of phthaloyl benzoic acid. Reduce the temperature to 125°C, then add SO 3 1440 kg of oleum with a content of 20% (1.6 times the dry weight of phthaloyl benzoic acid). After the addition, the temperature was raised to 179°C, and then the ring-closure reaction was carried out for 1 hour. After the reaction is completed, the product obtained in the closed-loop reaction vessel is pressed into the separation reaction vessel by an air pump, and 791.2 kg of dry anthraquinone with a light yellow color and a content of 99.09% is obtained through conventional separation, filtration, water treatment, and drying steps.

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Abstract

The process of close-ring synthesizing anthraquinone from o-benzoylbenzoic acid includes the following steps: A. heating o-benzoylbenzoic acid in close-ring reactor to eliminating surface water; B. adding fuming sulfuric acid with SO3 content of 16-24 % in 1.3-1.8 times weight of o-benzoylbenzoic acid and close-ring reaction at 138-200 deg.c for 1 hr; C. separating the reaction product in separating reactor, filtering, water washing, drying, etc. to obtain dry anthraquinone product. The present invention has less sulfuric acid consumption, low production cost, less exhausted waste acid, low power consumption and short reaction time.

Description

technical field [0001] The invention relates to a method for synthesizing anthraquinone, in particular to a method for synthesizing anthraquinone by ring-closing o-benzoylbenzoic acid. Background technique [0002] As a dye intermediate, anthraquinone is widely used in dye production enterprises. In the prior art, the synthesis process of anthraquinone is to put o-benzoylbenzoic acid into a closed-loop reactor, and after the temperature in the reactor is raised to 131° C., the temperature is raised to 140° C. while stirring, and the concentration of o-benzoylbenzoic acid is confirmed. The surface water has been evaporated, add sulfuric acid with a concentration of 98% according to 2.5 times of the dry weight of o-benzoylbenzoic acid, after adding, raise the temperature to 138°C, and keep it warm for 1 hour. Then move the reaction product to the isolation reactor and dilute with water. Finally, the obtained product is moved to a suction filter tank, filtered, washed with wa...

Claims

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Application Information

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IPC IPC(8): C07C46/00C07C50/18
Inventor 赵振国
Owner 赵振国
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