Cas:7210-76-6, Asischem Y51232

In a 1000 ml reaction flask with a reflux device and a hydrogen chloride absorption device, add 200 ml of anhydrous methanol (with moisture content less than 0.05%). Put 100 g of 6-methylanthrahydrazine into it and stir to dissolve. Heat and raise the temperature to 70�?�°C. Drop in 400 g of thiousulfuric acid. After the dropwise addition is completed, keep the temperature at this level for 1 to 5 hours. Take samples for testing (less than 2% of the raw material indicates the end of the reaction). Cool down to below 30C, and under normal pressure (below 90C), evaporate 550 ml of methanol. Then cool down and under reduced pressure (below 70�?�°C) remove the methanol. After cooling down to below 20�?�°C, add 400 g of dichloroethane, stir to dissolve for 45 minutes, add 200 g of tap water, adjust the pH to 6-9 with sodium bicarbonate, stir for 100 minutes. Let it stand and separate layers. Take the lower organic layer. The water layer is extracted once with 200 g of dichloroethane. Combine the organic layers, wash with 200 g of 6% sodium bicarbonate solution once, and then with 20% g of salt water once. The organic layer is stirred and dried with 6 g of anhydrous magnesium sulfate for 3 hours. Take a sample for moisture testing. If it is less than 1%, filter. The filter cake is washed with 20 g of dichloroethane, and the filtrate is combined. Recover 500 g of dichloroethane under normal pressure below 90C. Then cool down to below 70C and under reduced pressure for distillation until no obvious liquid flows out. Then conduct high vacuum distillation for purification. First collect the pre-boiling (apply to the next batch), and then collect the normal boiling point. Obtain about 104.7 g of 6-methylanthrahydrazine dry product. The moisture content is less than 0.1%. The yield is 95%.