Preparation method of 2,4-diethyl thioxanthone

A technology of diethylsulfur and xanthone, applied in 2 fields, can solve problems such as dark product color, violent reaction, complicated process, etc., and achieve the effects of warm reaction conditions, simple post-treatment, and little acid pollution

Inactive Publication Date: 2011-11-23
LIANYUNGANG SHENGNAN CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When preparing 2,4-diethylthioxanthone in the prior art, more than 98% concentrated sulfuric acid is directly used, the reaction is more violent, and the product is dark in color and the yield is low, and the yield is only about 80%; and The post-processing of the product requires distillation, the process is more complicated, and the energy consumption is high

Method used

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  • Preparation method of 2,4-diethyl thioxanthone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] Example 1. A kind of preparation method of 2,4-diethylthioxanthone, its steps are as follows: the concentrated sulfuric acid that concentration is more than 98% is mixed with the concentrated sulfuric acid that concentration is 88% in appropriate amount of water, treats that temperature drops to 5 After ℃, add m-diethylbenzene and dithiosalicylic acid, keep warm for 0.5 hours, then raise the temperature to 85 ℃ and react for 10 hours, after the temperature drops to 70 ℃, add water and toluene with a weight ratio of 1:0.5 for extraction operation, separate The water layer was removed, and the organic phase was successively washed with water and alkaline washed with liquid caustic soda with a mass percentage concentration of not less than 30% to remove residual acid, then distilled and desolvated, and toluene was recovered; the obtained crude product was dissolved in methanol at 45°C, and then lowered to 10 The product is precipitated below ℃, centrifuged and then dried t...

Embodiment 2

[0012] Example 2. A kind of preparation method of 2,4-diethylthioxanthone, its steps are as follows: add the concentrated sulfuric acid that concentration is more than 98% to be mixed with the concentrated sulfuric acid that concentration is 90% in appropriate amount of water, treat that temperature drops to 5 ℃, add m-diethylbenzene and dithiosalicylic acid, keep warm for 1.5 hours, then raise the temperature to 95 ℃ and react for 18 hours, after the temperature drops to 70 ℃, add water and toluene with a weight ratio of 1: 2 for extraction operation The water layer was removed, and the organic phase was successively washed with water and alkali washed with liquid caustic soda with a mass percentage concentration of not less than 30% to remove residual acid, then distilled and desolvated, and toluene was recovered; the obtained crude product was dissolved in methanol at 55°C, and then lowered to 10 The product is precipitated below ℃, centrifuged and then dried to obtain the ...

Embodiment 3

[0013] Example 3. A kind of preparation method of 2,4-diethylthioxanthone, its steps are as follows: dropwise add the concentrated sulfuric acid that concentration is more than 98% in appropriate water and be mixed with the concentrated sulfuric acid that concentration is 89%, treat that temperature drops to 5 After ℃, add m-diethylbenzene and dithiosalicylic acid, keep warm for 1 hour, then raise the temperature to 90 ℃ and react for 14 hours, after the temperature drops to 70 ℃, add water and toluene with a weight ratio of 1:1 for extraction operation The water layer was removed, and the organic phase was successively washed with water and alkali washed with liquid caustic soda with a mass percentage concentration of not less than 30% to remove residual acid, then distilled and desolvated, and toluene was recovered; the obtained crude product was dissolved in methanol at 50°C, and then lowered to 10 The product is precipitated below ℃, centrifuged and then dried to obtain th...

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Abstract

The invention relates to a preparation method of 2,4-diethyl thioxanthone. The preparation method of the 2,4-diethyl thioxanthone is characterized by finally obtaining a product, i.e. the 2,4-diethyl thioxanthone, through the processes of condensation, extraction, washing, caustic washing, distillation, dissolution and crystallization, centrifugation, drying, and the like by taking o-diethylbenzene and dithio-salicylic acid as main raw materials and sulphuric acid, toluene, sodium carbonate, methanol, and the like as auxiliary raw materials. The preparation method of the 2,4-diethyl thioxanthone, which is disclosed by the invention, has the advantages of higher yield reaching 85 percent through experimental determination, little acid pollution, easy aftertreatment, moderate reaction condition and capability of reducing the energy consumption because the distillation is not needed by the aftertreatment of the product.

Description

technical field [0001] The invention relates to a preparation method of 2,4-diethylthioxanthone. Background technique [0002] 2,4-Diethylthioxanthone is an important component of UV curing system. Because it has a longer ultraviolet absorption wavelength and can avoid the influence of pigments on ultraviolet light absorption, it is suitable for UV-curable coatings, inks and adhesives containing pigments. When preparing 2,4-diethylthioxanthone in the prior art, more than 98% concentrated sulfuric acid is directly used, the reaction is more violent, and the product is dark in color and the yield is low, and the yield is only about 80%; and The post-processing of the product requires distillation, the process is more complicated, and the energy consumption is high. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a 2,4-diethylthioxanthene with more reasonable process, higher yield, less acid pollution, simple pos...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D335/16
Inventor 周东
Owner LIANYUNGANG SHENGNAN CHEM
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