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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 sulfuric acid in the production, which increases the cost of waste treatment in the subsequent sequence, and the color of the obtained anthraquinone is dark

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] Get 1000kg of commercially available o-benzoylbenzoic acid with a water content of 10% and put it into a closed-loop reactor, heat up to 140° C. while stirring, and keep warm for 25 minutes to evaporate the water on the surface of o-benzoylbenzoic acid. Lower the temperature to 125°C, then add SO 3 Content is 17% oleum 1620kg (1.8 times of the dry weight of o-benzoylbenzoic acid). After the addition was complete, an exothermic reaction caused the temperature to rise to 178°C, followed by 1 hour of ring closure. The obtained product was subjected to conventional steps of isolation, filtration, washing with water, and drying to obtain 738.4 kg of dry anthraquinone with a light yellow color and a content of 99.05%.

Embodiment 2

[0015] Get 1000kg of commercially available o-benzoylbenzoic acid with a water content of 10% and put it into a closed-loop reactor, heat up to 140° C. while stirring, and keep warm for 25 minutes to evaporate the water on the surface of o-benzoylbenzoic acid. Lower the temperature to 125°C, then add SO 3 Content is 22% oleum 1350kg (1.5 times of the dry weight of o-benzoylbenzoic acid). After the addition was complete, the temperature was raised to 179°C, followed by a 1 hour ring closure reaction. After conventional process steps such as isolation, filtration, washing with water, and drying, 778.8 kg of dry anthraquinone with a light yellow color and a content of 99.07% can be obtained.

Embodiment 3

[0017] Get 1000kg of commercially available o-benzoylbenzoic acid with a water content of 10% and put it into a closed-loop reactor, heat up to 140° C. while stirring, and keep warm for 25 minutes to evaporate the water on the surface of o-benzoylbenzoic acid. Lower the temperature to 125°C, then add SO 3 Content is 20% oleum 1440kg (1.6 times of the dry weight of o-benzoylbenzoic acid). After the addition was complete, the temperature was raised to 179°C, followed by a 1 hour ring closure reaction. After the reaction is completed, use an air pump to press the product obtained in the closed-loop reactor into the isolation reactor, and then undergo conventional steps such as isolation, filtration, water washing, and drying to obtain 791.2 kg of dry anthraquinone with a light yellow color and a content of 99.09%.

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PUM

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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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