weigh 3.37g of o-nitroaniline (98.5% 0.024mol) and put it into a 50ml beaker, measure 3.0ml of 98% concentrated sulfuric acid, add and dissolve it, then add 20ml of water, stir to precipitate diazonium, and cool it to 0~5 ℃ for later use. Weigh 1.8g of NaNO2 to prepare a 30% solution, add it to the suspension of diazo components, react for 1h, the end point NaNO2 excess solution is strongly acidic, and add activated carbon to decolorize, filter, and prepare for coupling.
Weigh 4.30g of acetanilide, add 60ml, add 3.6ml of 30% sodium hydroxide solution to dissolve it, filter to remove impurities, then add 2.6ml of glacial acetic acid to it, stir to precipitate white precipitate, add 8.0g of sodium acetate, and keep the pH value of suspension at 6-7.
The diazonium salt is added to the above acetanilide suspension to immediately generate yellow pigment, the temperature is 10~15 ℃, the feeding time is 0.5h, the coupling ends, and the coupling components are slightly excessive. Wash with filtered water to neutral and dry at 80 ℃ to obtain the product.