5-Nitroisophthalic acid

5-Nitroisophthalic acid is a white leaf-like crystal, easily soluble in alcohol, ether and hot water. It can be used as an intermediate for the diagnostic drug new panchromatography (X-ray contrast agent) and as an intermediate for disperse dyes.

5-Nitroisophthalic acid

Uses

5-Nitroisophthalic acid has a wide range of uses and is an important intermediate for the synthesis of medicines, pesticides and dyes.

Synthesis method

A 5-nitroisophthalic acid synthesis method, characterized in that the method comprises the following steps:

a. Reaction: first, mix isophthalic acid and concentrated sulfuric acid and stir them evenly, heat them to 60-75℃, keep them warm for 0.5h, then add nitric acid, control the dripping speed to add them within 2-3.5h, after the nitric acid is added, control the temperature to 60-90℃ and gradually increase the temperature until the reaction is completed, and add water to decompose the reaction when the temperature is cooled to ≤50℃;

b. Washing and filtering: after the reaction and decomposition, cool the material to room temperature, remove the waste acid by filtration, wash the obtained filter cake with clean water for 3 times and then drain the washing water;

c. Recrystallization and purification: add the washed filter cake into pure water, heat and stir until dissolved, filter while hot, cool and crystallize, filter, and dry the solid to obtain 5-nitroisophthalic acid.

The invention uses isophthalic acid as a raw material and uses a small amount of concentrated sulfuric acid and 60% nitric acid to react and nitrate to synthesize 5-nitroisophthalic acid, thereby reducing the amount of sulfuric acid and nitric acid, improving the effective utilization rate of equipment, reducing the generation of waste liquid in production and the difficulty of treating the waste liquid, solving the nitration problem, and thus improving the economic benefit and environmental protection and social benefit of the product.