2,4,6-Trimethylphenol → 3,4,5-Tribromo-2,4,6-trimethyl-2,5-cyclohexadienone
Reaction equation
Br[CH2:2][C:3]1[C:8]([Br:9])=[C:7]([CH3:10])[C:6]([OH:11])=[C:5]([CH3:12])[C:4]=1[Br:13].CC1C=C(C)C=C(C)C=1O.BrBr.[Br:26]C1C(C)=C(O)C(C)=C(Br)C=1C>C(O)(=O)C.C([O-])(=O)C.[Na+].C(O)(=O)C.O>[Br:13][C:4]1[C:3]([Br:26])([CH3:2])[C:8]([Br:9])=[C:7]([CH3:10])[C:6](=[O:11])[C:5]=1[CH3:12]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 3
Procedure
The preparation of a halogenated phenol such as 4-bromomethyl-3, 5-dibromo-2, 6-dimethylphenol (tribromomesitol) can involve the following sequence: bromination of 2, 4, 6-trimethylphenol (mesitol) with 2 moles of bromine in acetic acid to prepare 3, 5-dibromo-2, 4, 6-trimethylphenol (dibromometisol) which is isolated by precipitation with water. K. Auwers & F. Rapp, Ann., 302, 153-71 (1898) and O. Jacobsen, Ann., 195, 265-92 (1879); the dibromomesit 1 is brominated in acetic acid sodium acetate buffer at low temperatures to afford an intermediate, 3, 4, 5-tribromo-2, 4, 6-trimethyl-2, 5-cyclohexadienone, which is isolated by fast precipitation with water and filtration; this solid slowly rearranges to tribromomesitol at room temperature, more quickly at higher temperatures. K. Fries & E. Brandes, Ann., 542, 48-77 (1939). This procedure to prepare tribromomesitol is complex and not industrially viable.
Sources & evidence
- ORD record
- ord-a117bc2fbc444d72b33f591291414928
- Source dataset
- uspto-grants-1987_08
- Patent number
- US04684752
Reaction notes
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