P-bromotoluene synthesis process

Abstract

The present invention discloses a p-bromotoluene synthesis process, which comprises: adding p-toluidine and hydrochloric acid to a reaction pot with a stirrer, a condenser, a thermometer and a dropping funnel, carrying out stirring heating to make the p-toluidine be dissolved, cooling to a temperature of less than or equal to 12 DEG C, adding a sodium nitrite solution in a dropwise manner to achieve an end point, continuously stirring for 30 min, adding a cuprous bromide hydrobromic acid solution to the reaction solution, stirring for 2 h at a temperature of 25-40 DEG C, heating the reaction solution to a temperature of 70-80 DEG C, carrying out thermal insulation for 1 h, adding water vapor to the reaction solution, distilling, separating the liquid, carrying out pressure reducing distillation, and collecting the distillate at a temperature of 104-106 DEG C to obtain the white crystal p-bromotoluene. According to the present invention, no by-product is formed during the p-bromotoluene synthesis process, the cuprous bromide easily reacts with the diazo salt under the protection of hydrobromic acid, the reaction efficiency is high, the reaction is rapid, the product yield achieves 97.82%, and the purity achieves 99.99%.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a synthesis process of p-bromotoluene. Background technique [0002] P-bromotoluene is a white crystal. The melting point is 28.5°C, the boiling point is 184.3°C, 61.9°C (1.33kPa), the relative density is 1.3955 (20 / 4°C), and the refractive index is 1.5477. P-bromotoluene is soluble in ethanol, ether and benzene, but insoluble in water. In the current p-bromotoluene synthesis process method, the technical process is not easy to implement, the resulting p-bromotoluene product has low purity, the single-pass conversion rate of reactants is low, the production process is complicated, the production efficiency is low and the cost is high, and it is not suitable for large-scale production. . Contents of the invention [0003] In order to overcome the above-mentioned technical problems existing in the prior art field, the object of the present invention ...

AI Technical Summary

Problems solved by technology

In the current p-bromotoluene synthesis process method, the technical process is not easy to implement, the resulting p-bromotoluene product has low purity, the single-pass conversion rate of reactants is low, the production process is complicated, the production efficiency is low and the cost is high, and it is not suitable for large-scale production.