Method for preparing 1,2,4 acid through synthesis in homogeneous phase between water and alcohol solvent

Abstract

This invention relates to a homogeneous method for preparing 1, 2, 4-acid in water-alcohol solvent. The method comprises: dissolving beta-naphthol with ethanol instead of liquid alkali, and performing nitration reaction, addition reaction and sulfonation reaction to obtain the product. The yield of 1,2,4-acid is up to 70-74%, the consumption of H2SO4 is reduced by nearly 1 / 3, the recovery rate of ethanol solvent is up to 80-85%, and the generation amount of wastetwaer is 1 / 2 that of alkali solvent method. The method has such advantages as adequate utilization of resources, high apparatus utility and low production cost. The method can be widely used to prepare 1, 2, 4-acid, an intermediate for producing naphthalene series dyes. The obtained 1,2,4-acid can be widely used to synthesize acid complex pink B, acid mordant black R, acid complex blue GGN and acid mordant bordeaux BN dyes and azo dyes.

Description

technical field [0001] The invention belongs to the technical field of preparation of naphthalene dye intermediates, in particular to a preparation method for homogeneously synthesizing 1,2,4-acid (ie 1-amino-2-naphthol-4-sulfonic acid) in a water-alcohol solvent. Background technique [0002] The shift of the world's textile and dye production center from Europe and the United States to Asia has created an excellent opportunity for the development of my country's dye industry. The upgrading of dye products, the rapid development of production and export situations have greatly stimulated and promoted the research and development of new varieties of dye intermediates. In recent years, my country's dye intermediate industry has grown at an average annual rate of about 10%, among which naphthalene intermediates are an important category in the dye intermediate industry. At present, some main unit reactions in the production of naphthalene dye intermediates in my country, such...

AI Technical Summary

Problems solved by technology

At present, some main unit reactions in the production of naphthalene dye intermediates in my country, such as nitrosation, sulfonation, nitration, reduction, etc., still mainly adopt traditional processes, because the manufacturing process of the dye intermediates involves a large number of different raw materials and more reaction units , so the amount of three wastes produced is large and the composition is complex, especially the wastewater treatment is difficult, which is an urgent problem to be solved in the industrial production of dye intermediates

[0003] Existing methods for the production of 1,2,4-acids, such as the synthesis of alkali-soluble methods for industrial production, that is, dissolving β-naphthol with liquid alkali, a-nitrosation reaction with nitrous acid at low temperature, and then reacting with sulfurous acid Addition reaction of sodium hydrogen, and finally sulfonation reaction with sulfuric acid to obtain the product, the yield is low only 68%

Especially this reaction is carried out in very dilute alkali aqueous solution, by a batch of 300kg β-naphthol, need 3600 liters of sodium hydroxide aqueous solution to dissolve, carry out nitrosation in about 4500 liters of aqueous solution, produce 6300 liters of COD (chemical oxygen demand ) value greater than 18000mg / l acidic wastewater, seriously polluting the environment; at the same time, it is necessary to consume an equal amount of acid to neutralize the alkali that dissolves β-naphthol, resulting in more by-product sodium sulfate