| production method | with 2-chloro-4-nitroaniline, phenol, m-cresol as raw materials, first, 2-chloro-4-nitroaniline was diazotized, coupled with phenol, then its nitro group was reduced, then a second diazotization was carried out, and finally the product was obtained by coupling with m-cresol. The final product was obtained by filtration, grinding and drying.. 30% ml of water and 30ml of hydrochloric acid (60%) were added to the reactor, 30g of 2-chloro-4-nitroaniline () was added under stirring, and the slurry was made at room temperature for 2-3H. Then cooled to 0-5 deg C, in 5-10min evenly drop 25ml sodium nitrite solution (30%), heat preservation 3.5h. After filtration, 0.5g of a diazo solution of sulfamic acid was added to the filtrate. 80ml of water was added to the reactor, and 15ml of liquid alkali (40%) was added under stirring. After the temperature was raised to 30-40 ° C., 11g of phenol (98%) was added, and the mixture was stirred until all of the mixture was dissolved. Additional 98% ml of water, 25g of soda ash () and 1g of diffusion agent NNO were added, and the temperature was lowered to 0 °c. The above diazo liquid was uniformly added at 0-5 ° C. (added within 50-60min), and stirring was continued for 1-2H. pH = 9-10 must be maintained during the reaction. Coupling solution was obtained. Add 108g of sodium sulfide solution to the coupling solution (30%), slowly raise the temperature to 90 ℃ within H, keep the reaction for 7-7.5H, stand for 15min, filter while hot, wash the filter cake with hot water, combine the filtrate and washing water, and return to the reactor, under the protection of nitrogen, 30% hydrochloric acid was slowly added dropwise to adjust to pH = 7. By filtration, a reduced product cake was obtained. 300mL of water, 32ml of hydrochloric acid (30 %), and the reduced product cake were added to the reactor, and the slurry was stirred for 3H and cooled to 0-5 ℃. Within 5min, 22ml of sodium nitrite solution (30%) was uniformly added, and the reaction was maintained for 3-4H. After filtration, 0.5g of sulfamic acid was added to the filtrate to obtain a second diazotization solution. Add 70ml water into the reactor, add 15ml liquid alkali (40%) and 12.6g m-cresol under stirring, stir for 10-15min, add 300ml water, 25g soda ash (98%) and 1g NNO, then cool down to 0-5 ℃, the above second diazotization solution is slowly added dropwise in 50-80min, and pH = 9-10 shall be maintained during this period. The reaction was continued for 1.5h after addition, and then gradually increased to 85-90 ℃ for 1h. Then the temperature is cooled to 35-40 ℃, and 15% of the volume of the reaction liquid is added to salt, stirred for 30min, then cooled to 10 ℃, filtered, and the filter cake is washed with saturated salt to neutral, sanded and dried to obtain the finished product. |