Clean production method of p-anisidine

Abstract

The invention discloses a clean production method of p-anisidine. The clean production method comprises the following steps of (1) enabling nitrochlorobenzene, sodium hydroxide and methanol to be subjected to an etherification reaction so as to obtain etherification reaction liquid; (2) directly filtering the etherification reaction liquid obtained in the step (1) to obtain a filtrate and filter cakes, washing the filter cakes with the methanol, drying the washed filter cakes to obtain industrial-grade sodium chloride, and distilling the filtrate so as to obtain p-nitroanisole concentration liquid; and (3) under the condition that a hydrogenation catalyst exists, enabling the p-nitroanisole concentration liquid obtained in the step (2) to be subjected to a hydrogenation reduction reaction in the hydrogen atmosphere, and after the reaction is completed, performing after-treatment so as to obtain the p-anisidine. According to the clean production method, after the etherification reaction is finished, direction filtration is performed so that the sodium chloride is removed, then concentration treatment is performed on the etherification reaction liquid, the hydrogenation reaction is directly performed, the operation is simple and convenient, and the yield and the purity of the obtained product are high.

Description

technical field [0001] The invention belongs to the technical field of fine chemical synthesis, and in particular relates to a clean production method of p-aminoanisole. Background technique [0002] p-Aminoanisole is a traditional dye and pharmaceutical intermediate. In the dye industry, it can produce ice dyes, disperse dyes, vat dyes, reactive dyes and various chromophores, naphthols, etc.; it is mainly used in the pharmaceutical industry Synthesize traditional medicines such as adipine and indomethacin. In the dye industry, blue salt VB, bay red base GP, naphthol AS-SG, AS-RL, vat red are mainly synthesized, and p-aminoanisole can be used to synthesize 2-amino-4-acetamidoanisole. The compound is an important raw material for disperse dyes, and can be used to synthesize a series of disperse dyes, such as C.I. disperse blue 79, 226, 301, disperse violet 58, disperse navy blue S-2GL, etc.; it is mainly used in the synthesis of adipine and primaquine in the pharmaceutical i...

AI Technical Summary

Problems solved by technology

[0005] Although this method can significantly reduce the TOC of wastewater, it still has the following disadvantages: 1. The low TOC wastewater produced by it contains a large amount of sodium chloride, which needs to be evaporated and crystallized to obtain industrial grade sodium chloride, and the energy consumption is relatively high; 2. A large amount of resin is used in the treatment process, which leads to high cost; 3. In both reaction processes, methanol needs to be distilled once, resulting in an increase in the amount of methanol distillation and a corresponding increase in energy consumption