Iodine → 2-Bromo-4-fluorotoluene
Reaction equation
[Br:1]Br.[F:3][C:4]1[CH:9]=[CH:8][C:7]([CH3:10])=[CH:6][CH:5]=1.II.O>C(O)(=O)C.[Fe]>[Br:1][C:8]1[CH:9]=[C:4]([F:3])[CH:5]=[CH:6][C:7]=1[CH3:10].[Br:1][C:5]1[CH:6]=[C:7]([CH3:10])[CH:8]=[CH:9][C:4]=1[F:3]Participants
Reactant 4
Product 2
Reagents, catalysts & solvents 2
Procedure
A solution of 160 g of bromine in 60 ml of glacial acetic acid was added all at once to a solution of 110 g of 4-fluorotoluene in 40 ml of glacial acetic acid, to which 1.1 g of iron powder and 1.1 g of iodine had been added. The initially exothermic reaction was kept at 25° C. to 27° C., first by cooling with water and then with warm water. The mixture was subsequently stirred at the above temperature for 3 hours, the glacial acetic acid and unreacted 4-fluorotoluene were then distilled off in vacuo and a mixture consisting of 3-bromo-4-fluorotoluene (57%), 2-bromo-4-fluorotoluene (41.9%) and dibromo-4-fluorotoluene (1.1%) was subsequently distilled off under 20 mbars and between 65° C. and 85° C. 8 g of residue remained. The monobrominated isomers were separated by distillation on a column. 21.5 g of 2-bromo-4-fluorotoluene (boiling point: 176°-8° C. (normal pressure)) and 28.5 g of 3-bromo-4-fluorotoluene (boiling point 184°-5° C. (normal pressure)) were obtained.
Workup
- customThe initially exothermic reaction
- customwas kept at 25° C. to 27° C.
- distillationthe glacial acetic acid and unreacted 4-fluorotoluene were then distilled off in vacuo
- distillationwas subsequently distilled off under 20 mbars and between 65° C. and 85° C
- customThe monobrominated isomers were separated by distillation on a column
Sources & evidence
- ORD record
- ord-0a636197ed9540ed8cd72ec9988f639a
- Source dataset
- uspto-grants-1982_09
- Patent number
- US04351974
Reaction notes
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