Maintaining stirring, vacuum is turned on, R1 is pumped to 154.0 ± 1.0kg petroleum ether. After the addition, the temperature was lowered to 0 ~ 5 ℃, stirred for 2 ± 0.5h.
Maintain the stirring, turn on the vacuum, and pump 154.0 to 1.0 kg of petroleum ether into R1. After adding, the temperature is cooled to 0 to 5 degrees C and stirred by 2 to 0.5h.
Maintain mixing, open vacuum, and pump 154.0 ± 1.0kg of petroleum ether into R1. After the addition, the temperature is reduced to 0 ~ 5 ℃, and the mixture is stirred for 2 ± 0.5h.