Process for preparing aminoanisol and aniline by using mixture of nitroanisole and nitro chlorobenzene as raw materials

Abstract

The invention relates to a process for preparing aminoanisole and aniline by taking a mixture of a nitroanisole and nitrochlorobenzene as a raw material. The process comprises the following: (1) a step of the catalytic hydrogenation reaction and the catalytic dechlorination reaction, during which, methanol is taken as a solvent, the mixture of the nitroanisole and the nitrochlorobenzene is taken as the raw material, catalyst is added, hydrogen is aerated; (2) a step of the solid-liquid separation, during which, solid and liquid in the material obtained from the step (1) after the catalytic hydrogenation reaction and the catalytic dechlorination reaction are separated, a liquid phase comprises aminoanisole, aniline, methanol, hydrochloride and water and is utilized in the next step; (3) a step of the liquid-liquid separation, during which, the oil phase-water phase liquid-liquid separation is performed in the material obtained in the step (2), the aminoanisole and aniline in the oil phase is utilized in the next step; (4) a step of distillation separation, during which, the distillation separation is performed in the oil phase to produce products of paraphenetidine, ortho-anisidine and aniline. The process for preparing the aminoanisole and the aniline has the advantages that: (1) the cost is low, the preliminary treatment step is saved, the process is simple; (2) the process is clean, the energy consumption is low, the 'three wastes' are little; (3) the purity of the product is high.

Description

technical field [0001] The invention relates to a process for preparing aminoanisole and aniline by using a mixture of nitroanisole and nitrochlorobenzene as raw materials, belonging to the technical field of fine chemicals. Background technique [0002] P-aminoanisole and o-aminoanisole and aniline are important organic intermediates. At present, the process adopted in the preparation of p-aminoanisole and o-aminoanisole is to use p-nitroanisole and o-nitroanisole as raw materials respectively, through reduction, and then separated and refined; aniline is usually It is obtained by reducing nitrobenzene as raw material and then separating and refining. Usually the preparation of p-aminoanisole, o-aminoanisole and aniline is an independent preparation process and separation and refining process respectively. This traditional preparation process has the following disadvantages: since the preparation is based on a single component as a raw material, it needs The mixed raw mat...

AI Technical Summary

Problems solved by technology

Usually the preparation of p-aminoanisole, o-aminoanisole and aniline is an independent preparation process and separation and refining process respectively. This traditional preparation process has the following disadvantages: since the preparation is based on a single component as a raw material, it needs The mixed raw materials are pre-treated in advance to obtain the required single-component raw materials. The pre-treatment in the preparation process requires a lot of equipment and unit operations, which inevitably has the disadvantages of high energy consumption and high cost in the production process. A large amount of process wastewater is produced, causing serious environmental pollution and material loss, such as the treatment of these wastewater will greatly increase the cost

In the process of preparing aminoanisole, this technology adopting nitroanisole mixture as a raw material puts forward the following requirements to the raw materials, either requiring the etherification reaction of nitrochloroanisole to be carried out thoroughly, or requiring the hydrogenation reduction Nitrochlorobenzene is removed before the reaction, which inevitably leads to higher requirements for etherification reaction or pretreatment, thus increasing the cost of pretreatment

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