Method for preparing 2-amino-4-chloro-5-nitrophenol

Abstract

The invention relates to the field of dyeing industry, and in particular relates to a method for preparing 2-amino-4-chloro-5-nitrophenol. The method for preparing 2-amino-4-chloro-5-nitrophenol comprises the following steps: (1) by taking 2-amino-4-chlorophenol as a raw material, performing acetic anhydride acylation so as to obtain 2-acetamido-4-chlorophenol; (2) performing loop closure on the 2-acetamido-4-chlorophenol in the presence of a dehydrant so as to generate 5-chloro-2-methylbenzoxazole; (3) performing mixed acid nitration on the 5-chloro-2-methylbenzoxazole so as to generate 5-chloro-2-methyl-6-nitrobenzoxazole; (4) performing alkaline hydrolysis and acidification on the 5-chloro-2-methyl-6-nitrobenzoxazole, thereby obtaining the product 2-amino-4-chloro-5-nitrophenol, wherein the concentration of concentrated nitric acid used in the step (3) is 80-90%, and an acidifier used in the step (4) is concentrated hydrochloric acid. The method has the beneficial effects that as hair dye or a color former, the 2-amino-4-chloro-5-nitrophenol prepared by using the method is good in tinting strength, good in color fixation property and small in irritability to skin, and hair can be natural, soft and moist and glossy.

Description

technical field [0001] The invention relates to the field of printing and dyeing industry, in particular to a preparation method of 2-amino-4-chloro-5-nitrophenol. Background technique [0002] 2-Amino-4-chloro-5-nitrophenol is an important raw material for organic synthesis, which is used in the synthesis of herbicides, dyes, photosensitive material couplers and medicines. Several domestic manufacturers have carried out industrial trial production, but they have stopped production successively due to low product yield and poor quality. Currently, the main manufacturer of this product abroad is India's Vivimud Company, but they use sulfuric acid as a special process for this product. Dehydrating agent, the dehydration time is longer and takes 24 hours, and the product after dehydration is darker in color, resulting in a darker color in the final product. This product is widely used in cosmetics and fur printing and dyeing industries at home and abroad because of its unique ...

AI Technical Summary

Problems solved by technology

Several domestic manufacturers have carried out industrial trial production, but they have stopped production successively due to low product yield and poor quality. Currently, the main manufacturer of this product abroad is India's Vivimud Company, but they use sulfuric acid as a special process for this product. Dehydrating agent, it takes 24 hours for a longer dehydration time, and the product after dehydration is darker in color, resulting in a darker color in the final product