Green synthesis method for benzoin

Abstract

The invention discloses a green synthesis method for benzoin. The green synthesis method includes the steps of firstly, putting benzaldehyde and imidazole hydrochloride into a reaction kettle according to the molar ratio ranging from 1:0.003 to 1:0.015, adding absolute ethyl alcohol solvents accounting for, by mass, 60% to 75% of the benzaldehyde, adjusting the pH value of the reaction system to range from 7.8 to 8.5, and conducting reaction for 1.5 hours to 2.5 hours at the temperature ranging from 70 DEG C to 90 DEG C; secondly, after the reaction ends, placing the reaction kettle in the ice-water bath to be processed through crystallization and filtering, obtaining crystallization mother liquor and light yellow solid, washing the light yellow solid through alcohol to obtain white acicular crystals, and conducting drying under the normal pressure to obtain the finished product, namely, the benzoin. By means of the method, traditional virulent editpotassium cyanide catalysts or sodium cyanide catalysts are replaced, and therefore the new green chemical synthesis method capable of reducing by-products is achieved. The method solves the problems that at present, catalysts obtained through synthesis in the industry are high in toxicity or low in toxicity but difficult to synthetise, high in consumption, low in catalysis efficiency and high in production cost.

Description

technical field [0001] The invention relates to a green synthesis method of benzoin. Background technique [0002] Benzoin, also known as benzoin, has a chemical name of 1,2-diphenyl anhydrous ethanol ketone, which is a white needle-like crystal. As an important chemical raw material, benzoin is widely used as a photosensitizer for photosensitive resins, a dye intermediate, and an anti-cratering agent for powder coatings. Synthesis of ureides and preparation of diphenylethylenedione, diphenylethylenedione oxime, acetic acid benzoin compounds, etc. [0003] The traditional synthetic method of benzoin is to use benzaldehyde in hot absolute ethanol solution with potassium cyanide or sodium cyanide as a catalyst. This method has a high yield and is easy to operate. The only defect is that the catalyst is a highly toxic chemical , It is more troublesome in the storage and recovery of the catalyst. There are huge risks not only in production but also in safety, and wastewater t...

AI Technical Summary

Problems solved by technology

Solve the problems of difficult catalyst synthesis, large dosage, low catalytic efficiency and high production cost in the synthesis of benzoin in the industry

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