Method and device for purifying 1,4-bis (bromodifluoromethyl) benzene

A method for purifying 1,4-bis(bromodifluoromethyl)benzene, comprising the steps of:

• synthesizing 1,4-bis(bromodifluoromethyl)benzene from 1,4-bis(difluoromethyl)benzene by bromination to provide 1,4-bis(bromodifluoromethyl)benzene crude products;
• mixing diphenylmethane with the 1,4-bis(bromodifluoromethyl)benzene crude products to obtain a mixture, the diphenylmethane having a boiling point higher than that of the 1,4-bis(bromodifluoromethyl)benzene crude products;
• evaporating the mixture under a reduced pressure to obtain an evaporated liquid in a single-stage evaporating process and to provide an evaporated liquid which is purified 1,4-bis(bromodifluoromethyl)benzene;
• detecting the purity of the evaporated liquid in batches using gas chromatography (GC);
• and
• collecting selected batches of the evaporated liquid based on a result of said detecting, and discarding unselected batches of the evaporated liquid.