The chemical name of the reducing substance is 2-amino-4-acetamidoanisole, which is the most important supporting intermediate in the production of dyes. The dyes produced by using 2-amino-4-acetamidoanisole include disperse black, disperse blue, color matching series, etc., and the demand is huge, and there is no substitute on the market at present.
At present, there are two main methods for preparing the reducing materials: one is p-nitrochlorobenzene as the starting material, and the product is obtained by etherification, reduction synthesis of p-aminoanisole, p-aminoanisole acylation, nitration and reduction; The other is prepared by using 2,4-dinitrochlorobenzene as a raw material, etherification, reduction and selective acylation.
The first route has a long process. In the traditional process, the reduction of p-nitroanisole is carried out by a sodium sulfide process, and the reduction of 2-nitro-4-methoxyacetanilide is carried out by an iron powder process. The treatment of iron sludge residue, the nitrification process also produces a large amount of high concentration of dilute acid. Traditional sodium sulfide and iron powder reduction processes also have low yield, high consumption, and high production cost, which have been banned by the state.
Although the second process route has shortened the process, due to factors such as the inability to improve the yield of key links and many side reactions, no industrial reports have been reported so far.