Method for producing 2-acetylamino-6-nitrobenzoic acid by sodium chloride reduction

Abstract

The invention discloses a method for producing 2-acetylamino-6-nitrobenzoic acid by sodium chloride reduction. By the aid of steps of the method, the reaction yield is high and reaches 90% or above; due to the strong reducing property of a sodium chloride solution, the reaction speed is high, and a product is not easily oxidized, has good color and luster and is high in quality; complicated aftertreatment is not required, and equipment and operation are simple; little wastewater is produced and is easy to treat, and the method is a low-emission clean process; the sodium chloride solution obtained through recovering and treatment of hydrogen sulfide waste gas in the industries such as petrochemical industry and the like is recycled, and the cost is low.

Description

technical field [0001] The invention relates to a reduction method, in particular to a method for reducing and producing 2-acetylamino-6-nitrobenzoic acid with sodium chloride. Background technique [0002] Chinese alias of 5-amino-2-nitrobenzoic acid: 3-amino-6-nitrobenzoic acid, English name: 5-Amino-2-nitrobenzoic acid, English alias: 3-Amino-6-nitrobenzoic acid, CAS No.: 13280-60-9. [0003] Molecular formula: C7H6N2O4, molecular weight: 182.13. [0004] It is an important pharmaceutical intermediate and a key intermediate for the production of C.I. disperse blue 79, 79:1, 291, 291:1, 301 and other azo-type disperse dyes. Disperse dyes account for about 40% of global dye production. Because dark dyes with 2-acetamido-6-nitrobenzoic acid as coupling components have good color matching compatibility, they are widely used in polyester, acetate and other dyes. The dyeing of blended fibers has a huge demand, accounting for about 35% of the output of disperse dyes, so the t...

AI Technical Summary

Problems solved by technology

In this process route, because the intermediate product 2-acetylamino-6-nitrobenzoic acid is a carcinogen, it is unstable and easily oxidized; during the 6-position selective nitration reaction, it is not easy to control the end point of acylation, so it is necessary not to contain 2 in the product. 6-Nitrobenzoic acid, there must be a certain amount of bisacylate, the quality cannot meet the requirements of pharmaceutical and dye production

For example, the initial melting point of 2-acetylamino-6-nitrobenzoic acid should reach above 70°C. In order to improve the product quality, the separation and refining process must be added, which complicates the process, loses the advantages of the four-step reaction, and costs more. High (see CN1861577A)

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