40187-51-7

75-36-5

65-45-2

40187-51-7

1) Preparation of NaCl-AlCl3 low melting point mixed molten salt system: assemble a mechanical stirrer, condenser tube (connected to the tail gas HCl absorption device), 0~200°C thermometer and constant pressure dropping funnel in a 100 ml three-neck flask. The device was placed in a constant temperature oil bath. Quickly weigh 0.0648 mol (~8.64 g) of anhydrous aluminum chloride and 0.0648 mol (~3.79 g) of sodium chloride into the flask, turn on the mechanical stirring, and heat to 140°C until the solids are completely melted and the temperature is stable. Note: After about 25 minutes, the anhydrous aluminum chloride and sodium chloride should be in a molten state. 2) With stirring, weigh 0.036 mol (about 5.00 g) of salicylamide into a flask that has been heated to 140°C and allowed to melt, keeping the temperature in the flask stable. 3) Weigh 0.0432 mol (about 3.39 g) of acetyl chloride and add it slowly dropwise through a constant pressure dropping funnel into the reaction system for about 10 minutes. The reaction temperature was maintained at 140 °C and continued for 0.5 h to ensure complete reaction. The reaction was carried out in a NaCl-AlCl3 low melting point mixed molten salt system. 4) Immediately after completion of the reaction, 60 mL of acidic solution (consisting of 1 mL of concentrated hydrochloric acid and 59 mL of ice-water mixture) was added slowly (uniformly over about 5 min) to the system, at which time a yellowish solid was produced. After adding the acidic solution, continue stirring at room temperature for 30 minutes until no more yellowish solids are generated to obtain the suspension. 5) The suspension was filtered, the light yellow solid was collected, washed three times (5 mL each time) with hot water at 80°C, and then dried at 80°C for 5 hours to obtain the crude product. 6) The crude product was dissolved in 20 mL of ethanol and heated to reflux temperature to dissolve it completely. Subsequently, recrystallization was carried out in an ice bath, and the precipitated crystals were filtered and dried at 80 °C for 5 h. The final product was 5-acetyl-2-hydroxybenzamide as a white solid (purity ≥98.1%) in 92.2% yield.