Synthesis technology of nitrophenol and intermediate thereof

Abstract

The invention relates to a synthesis technology of nitrophenol and an intermediate thereof, and discloses a synthesis method of 2-amino-4-nitrophenol. The synthesis method of 2-amino-4-nitrophenol comprises the following steps: 1, reacting 2-aminophenol (I) with hydrochloric acid or sulfuric acid in an organic solvent to synthesize a compound (II), and directly carrying out a next step reaction without recovering the organic solvent; 2, carrying out low temperature nitric acid nitration on the compound (II) in the organic solvent to obtain a compound (III), and ending the reaction; and 3, adding a liquid alkali to the above obtained system, distilling the system to recover the organic solvent, mixing the obtained distillation residue with an inorganic acid, carrying out solid-liquid separation to obtain a compound (IV), carrying out distilling concentration on the obtained mother liquor to obtain a commercial byproduct sodium chloride or sodium sulfate, and recovering distillation cooling water to use the distillation cooling water in the reaction. The chemical equation is shown in the description, and R in chemical equation is a chloride ion or a bisulfate ion. The technology has the advantages of high continuous operability, high safety, almost no wastes, realization of needed production devices being routine reaction devices, and easiness in realization of industrialization.

Description

technical field [0001] The invention relates to a preparation method of an organic compound, in particular to a synthesis process of nitrophenol and its intermediate. Background technique [0002] 2-Amino-4-nitrophenol, as a chemical synthesis intermediate, is widely used in dyes including reactive black ACE, neutral black BL / BRL / BGL and pharmaceutical products such as antihypertensive drugs acebutolol, 2-butyl -6-nitroindole and other production. [0003] The methods for synthesizing 2-amino-4-nitrophenol can be divided into electrochemical reduction and chemical reduction. Among them, chemical reduction includes general chemical reagent chemical reduction and metal catalytic hydrogenation reduction. Due to factors such as high production costs and lack of electrochemical facilities, the electrochemical reduction method has not yet reached the level of industrialization. At present, the chemical reduction method, especially the selective reduction of the 2-nitro group in ...

AI Technical Summary

Problems solved by technology

It has the advantages of low pollution and high yield, but the disadvantage is that because the last step of the process is an acid-base neutralization process, a large amount of salt is inevitably trapped in the process of 2-amino-4-nitrophenol solid precipitation, resulting in 2- The active ingredient content of amino-4-nitrophenol is difficult to meet the production requirements of downstream products, so recrystallization and other treatments are required to treat 2-amino-4-nitrophenol

[0005] The invention discloses a synthesis process of nitrophenol and its intermediates. By simply modifying the substrate, the shortcomings of existing processes such as large pollution, low safety, substandard occupational health and low product quality are effectively avoided. , has the advantages of strong operability in series and high-quality products at one time

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