Continuous flow preparation method of 1, 2, 3-trichloropropane

Abstract

The invention relates to a continuous flow preparation method of 1, 2, 3-trichloropropane. The method comprises the following steps: in a continuous flow reaction device, simultaneously pumping 3-chloropropene liquid and liquid chlorine into the reaction device through a metering pump, and continuously reacting at -20-30 DEG C to obtain 1, 2, 3-trichloropropane. Compared with the prior art, the technical scheme provided by the invention has the advantages of small liquid holdup, large flux of liquid chlorine compared with chlorine, good mass and heat transfer effects, short reaction time, no generation of byproducts, smaller occupied area, high product yield and content, safety and reliability in reaction and suitability for large-scale industrial production.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a continuous flow preparation method of 1,2,3-trichloropropane. Background technique [0002] 1,2,3-Trichloropropane is an important chemical intermediate with a CAS number of 96-18-4 and a molecular formula of C 3 h 5 Cl 3 , whose structural formula is: [0003] . [0004] 1,2,3-Trichloropropane is an excellent solvent, mainly used as a degreasing agent, paint remover and solvent for motor washing, and can also be used to produce trichloropropene, pesticides chlormequat and oat enemy. As the key starting material for the synthesis of the second-generation nicotinic insecticides thiamethoxam, clothianidin and ritonavir, it has gradually attracted extensive attention from pesticide researchers in recent years,1,2, The 3-trichloropropane product can be cleaved to produce 2,3-dichloropropene, and 2-chloropropenyl isothiocyanate can be obtained by substit...

AI Technical Summary

Problems solved by technology

The reaction needs to be carried out in the absence of light, the reaction time is relatively long, and the SO produced in the reaction 2 1. The escape of HCl gas will pollute the environment, and the obtained product needs to be separated under reduced pressure, and even the sulfonated by-products need to be separated by washing with water, which is not conducive to industrial production

[0007] CN108640811A provides a method for synthesizing and preparing 1,2,3-trichloropropane from chloropropene, which uses gas-liquid reaction to pass chlorine gas into chloropropene, and maintains the reaction temperature at 20-40° C. through an ice-water bath Preparation of 1,2,3-trichloropropene, but the reaction time is long, the consumption of chlorine gas is huge and easy to escape, and the product needs to be washed with sodium carbonate aqueous solution to neutrality and desiccant and filtration are required. The purity of the refined product after the post-treatment process is as high as 96.5%, which is not very satisfactory

Although the method reaction is a continuous reaction, a large amount of nitrogen or other inert gas required for the reaction is used as a protective gas, and the input cost is high; the chlorine gas required for the reaction is more likely to overflow than liquid chlorine, which has certain harm to the health of production personnel; and In order to maintain the gas phase condition, it is necessary to maintain a high temperature condition. If the temperature is too high, certain side reactions will occur, and the byproducts are difficult to separate; the gas-gas reaction flux is small, the unit production capacity is limited, the equipment investment cost is high and the maintenance cost is expensive, which is harmful to the workers. The comprehensive quality requirements are high, and it is not suitable for large-scale industrial production from economic considerations