Method and device for purifying 1,4-bis (bromodifluoromethyl) benzene
View Patent ↗A method and a device for purifying 1,4-bis(bromodifluoromethyl)benzene are disclosed. In order to solve the problem of hard to purify and separate 1,4-bis(bromodifluoromethyl)benzene crude products, diphenylmethane that has a higher boiling point and does not interact with 1,4-bis(bromodifluoromethyl)benzene is mixed with the 1,4-bis(bromodifluoromethyl)benzene crude products for evaporation. Afterwards, the purity of the vaporized product is detected and only that reaching an expected purity is collected to obtain high-purity 1,4-bis(bromodifluoromethyl)benzene.
1. A method for purifying 1,4-bis(bromodifluoromethyl)benzene, comprising the steps of:
mixing diphenylmethane with 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 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; and
collecting selected batches of the evaporated liquid based on a result of said detecting.
2. The method for purifying 1,4-bis(bromodifluoromethyl)benzene of claim 1 , wherein the 1,4-bis(bromodifluoromethyl)benzene crude products are synthesized from 1,4-bis(difluoromethyl)benzene by bromination.
3. The method for purifying 1,4-bis(bromodifluoromethyl)benzene of claim 1 , wherein the step of evaporating the mixture is performed under a reduced pressure.
4. The method for purifying 1,4-bis(bromodifluoromethyl)benzene of claim 1 , wherein the step of detecting the purity of the evaporate product is performed using gas chromatography (GC).
5. The method for purifying 1,4-bis(bromodifluoromethyl)benzene of claim 3 , wherein the reduced pressure is below 10 torr.
6. The method for purifying 1,4-bis(bromodifluoromethyl)benzene of claim 1 , wherein the selected batches have a purity exceeding 99.6%.
7. 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.
8. The method for purifying 1,4-bis(bromodifluoromethyl)benzene of claim 7 , wherein evaporating the mixture takes place under a reduced pressure which is below 10 torr.
9. The method for purifying 1,4-bis(bromodifluoromethyl)benzene of claim 7 , wherein the selected batches have a purity exceeding 99.6%.