1,2,4,5-Tetrabromo-3,6-bis(bromomethyl)benzene

Synthesis of tetrabromopara-xylene 1 000 kg of bromine and 3 kg of anhydrous AlBr3 were sequentially added to the reaction kettle. Use ice brine to cool to 0 ~ 3 ℃, slowly add 80 kg of xylene under stirring. When there are lumps or viscosity in the reaction kettle, add 450 kg of bromine to dilute. The temperature can be controlled at 30-35 ℃ during the dilution process. After the lumps disappear, cool to 10-15 ℃, continue to add the remaining xylene, and react at 20 ℃ for 4-6 h. Distill out excess bromine. Put the reaction solution in a centrifuge to filter and spin dry. Recrystallized from methanol, melting point 253～254℃. Synthesis of hexabromopara-xylene 80 kg of carbon tetrachloride was added to the reactor, and 42 kg of tetrabromopara-xylene prepared above was added with stirring. Under N2 protection, slowly add bromine in carbon tetrachloride solution (32 kg bromine is dissolved in 50L carbon tetrachloride), and heat to reflux for 15 h. Then cool to about 3°C. Centrifugal filtration, drying to obtain α, α', 2, 3, 5, 6-hexabromopara-xylene.

This product is a new type of pollution-free fiber flame retardant. Compared with the conventional product polybrominated diphenyl ether, the addition of this flame retardant has no toxic dibenzobis [mouth evil] when the polymer is hot or burned. Alkanes and polybrominated dibenzofurans are produced. This type of flame retardant is quite popular among the new flame retardants introduced in the 1990s in the United States. This product is easy to use, and can be added directly in the post-processing of textiles (polyester, viscose, blended, cotton, pure polyester) to complete the whole process at room temperature.

Molecular Weight:579.5
XLogP3:5.8
Rotatable Bond Count:2
Exact Mass:579.53518
Monoisotopic Mass:573.54133
Heavy Atom Count:14
Complexity:151
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes