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Introduction to laboratory preparation steps of sodium besylate

Dec. 25, 2019

This article will mainly introduce the laboratory preparation method of sodium besylate.

Sodium besylate is mainly used to synthesize a new type of pesticide, insecticide, for dye intermediates, washing aids and foundry industry. Slurry conditioner for chemical industry and synthetic detergents.

The steps for preparing sodium besylate in the laboratory are as follows

Preparation principle

Sulfonation is an electrophilic substitution reaction. The ease of sulfonation of aromatic hydrocarbon derivatives depends on the nature of the substituents on the aromatic hydrocarbon. When there are nucleophilic substituents on the aromatic ring, the sulfonation reaction is favorable. The sulfonation reaction should select the sulfonating agent according to the nature of the sulfonate. The most commonly used sulfonating agents are: sulfuric acid, chlorosulfonic acid, and oleum. The sulfonation of benzene is difficult, and fuming sulfuric acid should be used as the sulfonating agent.

The main instruments and reagents used

1, instrument:

Three-necked flask, spherical condenser tube, Y-shaped tube, dropping funnel, beaker, thermometer, electric heating jacket, suction filter device, tray balance, measuring cylinder.

2, reagents:

20mL of benzene, 14mL of oleum (8%), calcium carbonate, calcium hydroxide, sodium carbonate

Experimental steps

1, sulfonation:

In a 150-mL three-necked flask equipped with a thermometer, a spherical condenser, and a dropping funnel, add 20 mL of benzene, and slowly add 14 mL of 8% fuming sulfuric acid (within 30 minutes) under constant stirring, and control the reaction temperature with a cold water bath Not more than 75 ° C.

After the addition of oleum, the mixture was heated under reflux with an electric heating mantle for 2 h. It is preferable that the condensation limit of the benzene vapor in the spherical condenser tube does not exceed the first sphere.

2, neutralize:

When the temperature of the reaction solution reaches 100 ° C. and there is no condensation of benzene vapor in the spherical condenser, the sulfonation is complete. The material is cooled below 50 ° C, poured into a beaker containing 100 mL of water, and neutralized with calcium hydroxide and calcium carbonate to pH = 6.

3. Filtration and separation of sulfonated products:

The neutralization solution was filtered to remove calcium sulfate. Rinse the filter cake with 30 mL of hot water, remove the filter cake into a 500 mL beaker, add 50 mL of hot water, stir, filter, rinse the filter cake with 30 mL of hot water, and combine the washing solution with the filtrate.

Sodium carbonate was added to the filtrate to transform calcium besylate into sodium salt. The calcium carbonate was removed by filtration (suction filtration, using double filter paper), and the filter cake was washed with a small amount of water.

The filtrate was first evaporated in a beaker, and then transferred to an evaporation dish to evaporate until sodium besylate crystals appeared, cooled, crystallized, filtered, and dried. The product is weighed and the yield is calculated.

The above is a brief introduction of haihangindustry's laboratory preparation method of sodium besylate. Contact us for COA and MSDS of sodium besylate!

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