New synthesis process of naftifine drug intermediate N-methyl-1-naphthalenemethylamine

Abstract

The invention discloses a new synthesis process of a naftifine drug intermediate N-methyl-1-naphthalenemethylamine. The process includes: adding phosphoric acid, concentrated hydrochloric acid, industrial naphthalene, paraformaldehyde and a catalyst, performing heating, introducing HCL gas, and carrying out reaction to obtain a 1-chloromethylnaphthalene crude product; performing cooling, dropwiseadding the 1-chloromethylnaphthalene crude product into a methanolamine solution, and carrying out reaction to obtain an N-methyl-1-naphthalenemethylamine crude product; performing evaporating to remove the redundant methanolamine solution, adjusting the alkali with a sodium hydroxide aqueous solution, conducting washing with water for layering, adding water and dichloromethane into an organic layer, adjusting the pH value with hydrochloric acid, performing layering, taking the water layer, and adjusting alkali with a sodium hydroxide solution to obtain a crude product, and carrying out reduced pressure rectification to obtain a finished product. According to the method, the N-methyl-1-naphthalenemethylamine finished product is successfully synthesized directly in a one-pot mode, the situation that the product yield is reduced due to the fact that a lot of residues are generated is avoided, meanwhile, the safety risk in the rectification process is avoided, the purity of the crude product is greatly improved, the cost is low, and the production safety is high.

Description

technical field [0001] The invention discloses a new synthesis process of N-methyl-1-naphthylmethylamine, a drug intermediate of naftifine. The process uses cheap naphthalene as the main raw material, synthesizes 1-chloromethylnaphthalene through chloromethylation reaction, and cooks in one pot Synthesis of N-methyl-1-naphthylmethylamine. Background technique [0002] It has been reported in the literature that the process of synthesizing N-methyl-1-naphthylmethylamine used to take naphthalene as the starting material, synthesize 1-chloromethylnaphthalene through chloromethylation, and then react with 30% methylamine ethanol solution after rectification of the product The crude product of N-methyl-1-naphthylmethylamine was synthesized, and the finished product was obtained after vacuum distillation. [0003] Above-mentioned synthetic N-methyl-1-naphthylmethylamine technique has following shortcoming: [0004] 1. The rectification of 1-chloromethylnaphthalene has a relative...

AI Technical Summary

Problems solved by technology

[0004] 1. The rectification of 1-chloromethylnaphthalene has a large safety risk, and the total yield of N-methyl-1-naphthylmethylamine after rectification is low

[0005] 2. 1-Chloromethylnaphthalene rectification produces more residues during the rectification process, which is difficult to handle, increases production costs, and pollutes the environment

[0006] 3. The crude product of N-methyl-1-naphthylmethylamine is low in purity and contains many impurities. The yield of finished product obtained by direct vacuum distillation is low, and the former fraction takes away more products. If the amount of the former fraction is controlled, the later product will not qualified