Preparation method of 2-nitrochlorobenzene-4-sulfamide

Abstract

The invention provides a preparation method of 2-nitrochlorobenzene-4-sulfamide. The preparation method comprises the following steps of adding 2-nitrochlorobenzene-4-sulfonyl chloride and ammonia salt into water, and using Turkey red oil as a wetting agent; adding inorganic alkaline for controlling the pH (potential of hydrogen) value of the system to be 7 to 9, and performing ammonolysis reaction at the temperature of 30 to 60 DEG C, so as to obtain the corresponding product, namely the 2-nitrochlorobenzene-4-sulfamide. The preparation method has the advantages that the ammonia water is replaced with the ammonia salt, so that the adverse effect due to volatilizing of the ammonia water is avoided, the pollution to environment is low, and the hazard to the health of human body can be effectively avoided; all raw materials are added by one step, so that the waste of time and labor in the batch adding process is reduced, the reaction conditions are improved, the reaction can be performedat lower pH value, the decomposing of the 2-nitrochlorobenzene-4-sulfamide is reduced, the production of byproduct is reduced, and the yield rate is increased by 10% or above; because the reaction temperature is higher, the adding of ice is not required, so that the energy consumption is decreased.

Description

technical field [0001] The invention relates to a preparation method of 2-nitrochlorobenzene-4-sulfonamide, belonging to the technical field of dye intermediate synthesis. Background technique [0002] 2-Aminophenol-4-sulfonamide is an important dye intermediate, which can be used in the production of acid dyes, direct dyes and solvent dyes. For example: acid yellow 114, 116: 1, 128, 137, 151; acid orange 60, 64, 76, 87, 87: 1, 88, 107, 139, 162, 173; acid red 182, 213, 277, 296, 445; Acid Violet 68, 70, 87; Acid Blue 168; Acid Green 56; Direct Red 98, 181; Direct Violet 46, 66; Solvent Red 102, etc. [0003] And 2-nitrochlorobenzene-4-sulfonamide is the key raw material for the synthesis of intermediate 2-aminophenol-4-sulfonamide. The current general method for synthesizing 2-nitrochlorobenzene-4-sulfonamide is to condense 2-nitrochlorobenzene-4-sulfonyl chloride and ammonia water at a low temperature of 15°C. The chemical reaction equation is as follows: [0004] ...

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Problems solved by technology

Therefore, feeding in batches for a long time will cause workers to be frequently exposed to ammonia water environment for a long time, which will bring great harm to the industrial production environment and operators.

[0008] Since the ammoniation reaction is an exothermic reaction, in order to maintain the condensation below 20 degrees Celsius, the industrial production process must continue to add ice to cool down, especially in summer, so that the volume of the reaction feed liquid continues to increase. At present, the final product of industrial production is 2-nitrochloride. The method of benzene-4-sulfonamide is ammonification, alkali hydrolysis, reduction one-pot method, each step in the middle is not separated, because the volume of the ammonification process is getting larger and larger, resulting in the final product 2-nitrochlorobenzene-4-sulfonamide The production capacity is reduced; at the same time, the final product 2-nitrochlorobenzene-4-sulfonamide has a certain solubility in water, and the consequence of the increase in the volume of the feed liquid is that the product yield decreases

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