2-Methyl anthraquinone, yellow crystal, insoluble in water, soluble in ethanol, ether, benzene and ethyl acetate. It is of great industrial value. It is not only used as a chemical intermediate for the synthesis of dark and high-quality dyes but also as an efficient pulping additive in the papermaking process. It is also widely used in medicine, pesticides and many other aspects. The most common 2-methyl anthraquinones are 2-methyl anthraquinone and 2-ethyl anthraquinone. 2-methyl anthraquinone can be modified according to different needs to synthesize the target compound.
The use of 2-methyl anthraquinone is mainly reflected in the following aspects:
In terms of dyes:
It is used to produce high-grade dyes and intermediates, so there is a great demand for this product in terms of shades. Firstly, 2-Methylanthraquinone is chlorinated or nitrated, and then a wide variety of anthraquinone dyes can be synthesized. Statistics show hundreds of anthraquinone dyes with significant commercial value and broad prospects. For example, a synthetic method of reducing gold Orange G natural dye has been developed.
The specific steps are as follows:
(1) bromination reaction: 2-Methylanthraquinone is used as raw material and aprotic solvent as a medium to react with liquid bromine in a weak alkali environment to produce 1-Bromo-2-methyl anthraquinone;
(2) Coupling reaction: taking 1-Bromo-2-methyl anthraquinone as raw material, adding a catalyst and aprotic solvent as a medium, the coupling reaction takes place to produce diquinone C;
(3) Closed-loop oxidation reaction: with quinone C as raw material, in the stable solvent formed by a strong base and alcohol solvent, the closed-loop response occurs first, and then through air oxidation reaction to obtain the original dye of reduced gold-orange G. The process route has fewer by-products, less environmental pollution, higher reaction yield, shorter reaction time and more convenient industrial production
Synthetic method 1 of 2-methyl anthraquinone -- anthracene oxidation method
Among several existing synthetic methods of alkyl anthraquinone at home and abroad, the anthracene oxidation method is the greenest; atomic utilization is the highest and most environment-friendly synthetic method. Its yield can reach more than 99% without three wastes pollution. Among them, the oxidant of the anthracene gas phase oxidation method can use oxygen, and almost all alkyl anthracenes can be converted to alkyl anthraquinone under the catalysis of vanadium pentoxide. The purity of alkyl anthraquinone obtained by gas-phase oxidation of anthracene is very high, and the product can be produced directly without purification.
Anthracene liquid-phase oxidation method, the method of synthetic 2-methyl anthraquinone, uses potassium dichromate as an oxidant and can react at about 100 ° C. the required temperature is not high, and the conditions are mild, but acidic conditions are required. A certain amount of acidic wastewater will be produced, but it is far less than the three wastes produced by other methods.