Method for preparing 1-nitroanthraquinone by using supergravity nitration reactor

Abstract

The invention discloses a method for preparing 1-nitroanthraquinone by a supergravity nitration reactor, which specifically comprises the following steps: sequentially adding a solvent, anthraquinone and a nitrating agent into the supergravity nitration reactor, mixing at a certain rotating speed, continuously dropwise adding a mixed acid catalyst under a heating condition, and reacting at constant temperature for a period of time after dropwise adding, thereby obtaining the 1-nitroanthraquinone. And purifying the reaction product to obtain the 1-nitroanthraquinone. According to the method, the selectivity, yield and purity of the prepared 1-nitroanthraquinone are effectively improved, meanwhile, the problem of material viscosity is solved, and the method is easy and convenient to operate, safe, environmentally friendly and suitable for industrial production of the 1-nitroanthraquinone.

Description

technical field [0001] The invention belongs to the technical field of synthesis of dye intermediates, and in particular relates to a method for preparing 1-nitroanthraquinone in a high-gravity nitration reactor. Background technique [0002] 1-Nitroanthraquinone is an important dye intermediate, mainly used to prepare 1-aminoanthraquinone. At present, the preparation methods of 1-nitroanthraquinone mainly include anthraquinone direct nitration method, phthalic anhydride direct nitration method, anthrone method, naphthoquinone method, etc., and the most commonly used method is anthraquinone nitration method. The method is generally completed in a stirred tank reactor, and the reaction product is not only 1-nitroanthraquinone, but also 2-nitroanthraquinone, unreacted anthraquinone, dinitro and other isomer by-products. This is due to the exothermic heat of the process, and the increase in temperature leads to poor reaction selectivity, which limits the increase in the yield ...

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Problems solved by technology

Although this method is relatively mild, the conversion rate of raw materials is poor, and a variety of reagents are required, which is difficult to recover and is not conducive to industrial production.

[0004] Patent CN104030927A discloses a method for preparing 1-nitroanthraquinone with a metal-modified molecular sieve as a catalyst. Nitrification is continuously added to the reaction substrate mixed with anthraquinone, metal-modified molecular sieve catalyst, acid promoter and solvent. Reagent, after the reaction is complete, the purification process is carried out. Although this method improves the substitution of the nitrate-based anthracycline-based oxygen atoms in the directional position and reduces by-products, the molecular sieve needs high-temperature activation treatment, and metal halides or their salts are required. Modification treatment, the process cost is too high, which limits the large-scale use of this method

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