O-Xylene → Benzene, 1,2,4,5-tetrabromo-3,6-dimethyl-

Temperature

5 °C

In a glass resin flask, a mixture of 1000 parts bromine and 3 parts of aluminum tribromide was cooled at 5° C and 83 parts of p-xylene were added dropwise with rapid stirring and continued cooling. After adding about 3/4 of the xylene, the reaction mixture became viscous forming large chunks of product. The mixture was diluted with 454 parts of bromine and the temperature was brought to 30° C. The heating and stirring gradually broke down the chunks of product to a fine powder. The mixture was then cooled to 15° C and the remaining xylene was added. Most of the excess bromine was removed by distillation. The solid was removed from the reaction flask and leached with cold methanol to remove excess bromine. The product was then dissolved in hot benzene and filtered. The solvent was then driven off and 323 parts (98.3% yield) of tetrabromo-p-xylene was obtained as crystals having the melting point of 253°-254° C.

1. temperaturecontinued cooling
2. customwas brought to 30° C
3. stirringThe heating and stirring gradually
4. temperatureThe mixture was then cooled to 15° C
5. customMost of the excess bromine was removed by distillation
6. customThe solid was removed from the reaction flask
7. customto remove excess bromine
8. dissolutionThe product was then dissolved in hot benzene
9. filtrationfiltered

ORD record

ord-6bcf70e5348c40dc9e45470094ed0410

Source dataset

uspto-grants-1978_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04107104