Esterifying method and application thereof

Abstract

The invention discloses an esterification method and its application. The method provided by the invention includes the following steps: after stirring and mixing the mercaptopropionic acid, the catalyst and methanol, stopping the stirring and standing for reaction, and then obtaining the product. The esterification reaction temperature of the preparation method of methyl mercaptopropionate provided by the present invention is slightly reduced, and the temperature of the traditional esterification reaction can be reduced by 2-4 ° C, and no forced stirring is required during the static reaction process, which saves manpower and material resources. The reaction between mercaptopropionic acid and methanol produces methyl mercaptopropionate and water in the oil phase, forming a two-phase system. The water phase is lighter and rises slowly, and the oil phase is heavier and sinks slowly. The separation of the two phases does not affect the The further contact reaction of mercaptopropionic acid and methanol, therefore, the esterification reaction can proceed smoothly until an equilibrium system is formed, and the entire esterification reaction is completed; and, the conversion rate of the whole static esterification reaction is equivalent to that of the traditional forced stirring , and slightly increased.

Description

technical field [0001] The invention relates to a preparation method of esterification reaction, in particular to an esterification method and application thereof. Background technique [0002] Methyl mercaptopropionate (Cas: 2935-90-2) is a colorless or very light yellow transparent liquid, soluble in various organic solvents, insoluble in water, and is used as an intermediate in organic synthesis. Used as pharmaceutical intermediates. [0003] In the prior art, there are mainly two methods to prepare methyl mercaptopropionate: one is to add trimethylchlorosilane dropwise to the methanol solution of 3-mercaptopropionic acid at about -10°C, and the reaction mixture is Stir at 0°C for 1 h, then stir at room temperature for 1 h, then adjust the pH value to 8 with aqueous sodium bicarbonate solution, then extract with dichloromethane, wash the organic phase with sodium bicarbonate, dry with magnesium sulfate, filter, and depressurize the filtrate Distillation to finally obtai...

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Problems solved by technology

[0003] In the prior art, there are mainly two methods to prepare methyl mercaptopropionate: one is to add trimethylchlorosilane dropwise to the methanol solution of 3-mercaptopropionic acid at about -10°C, and the reaction mixture is Stir at 0°C for 1 h, then stir at room temperature for 1 h, then adjust the pH value to 8 with aqueous sodium bicarbonate solution, then extract with dichloromethane, wash the organic phase with sodium bicarbonate, dry with magnesium sulfate, filter, and depressurize the filtrate Distillation to finally obtain the product, but this method requires high temperature, and the entire reaction needs to be carried out under stirring, which has high energy consumption and is not conducive to large-scale industrial production; another method is completed by mercaptopropionic acid and methanol under stirring conditions Yes, the stirring reaction time is generally required to be 3 hours. After the stirring reaction is completed, the esterification liquid needs to be statically separated to separate the methyl mercaptopropionate in the oil phase from the water phase. In order to ensure the complete separation of the oil phase and the water phase, Sufficient static separation time must be ensured, so the disadvantage of this method is that the entire esterification reaction takes a long time