Clear very faintly yellow liquid
1-Bromo-3-(trifluoromethoxy)benzene may be used in the preparation of 1,2-dehydro-3-(trifluoromethoxy)benzene. It may be used in the synthesis of new electronically deficient atropisomeric diphosphine ligand (S)-CF3O-BiPhep [2,2′-bis(diphenylphosphino)-6,6′-ditrifluoromethoxy-1,1′-biphenyl].
1-Bromo-3-(trifluoromethoxy)benzene undergoes Diels-Alder reaction with lithium diisopropylamide (LDA) in THF and furan, to yield the corresponding 1,4-dihydro-1,4-epoxy-5- or 6-(trifluoromethoxy)naphthalenes.
The general procedure for the synthesis of 3-trifluoromethoxybromobenzene from p-trifluoromethoxyaniline is described below:
Example 5 (comparative experiment) Preparation of 1-bromo-3-trifluoromethoxybenzene using bromine (Br2) in acetic acid medium. This was done as follows: 60 g of acetic acid was added to a 100 mL round bottom flask, followed by the slow addition of 30 g of 4-trifluoromethoxyaniline. After cooling the reaction mixture to 0-5 °C, 27 g of bromine was slowly added dropwise. Upon completion of the reaction, the reaction mixture was analyzed by gas chromatography, which showed 20% unreacted 4-trifluoromethoxyaniline, 37% monobrominated derivatives and more than 41% dibrominated derivatives.
[1] Patent: WO2007/107820, 2007, A2. Location in patent: Page/Page column 9
