反应详情

温度

20 °C

A solution of bromine (14.6 g, 91.3 mmol) in carbon tetrachloride (100 mL) is added to a stirred mixture of 4'-Methoxy-[1,1'-biphenyl]-4-carboxylic acid, ethyl ester (23.4 g, 91.3 mmol) and silica gal (100 g of particle size 0.040-0.063 mm; Merck 1.09385) in carbon tetrachloride (350 mL). The mixture is stirred at 20° C. for 4 h after which the silica gel is removed by filtration. The filtrate is washed with aqueous sodium hydrogen carbonate (200 mL of 1 M) followed by aqueous sodium thiosulphate (50 mL of 2 M), dried (Na2SO4), filtered and evaporated to dryness under reduced pressure to give the crude product which is recrystallised from ether-cyclohexane to give 3'-bromo-4'-methoxy-[1,1'-biphenyl]-4-carboxylic acid, ethyl ester as a colourless crystalline solid, m.p. 114-115° C.

1. customis removed by filtration
2. washThe filtrate is washed with aqueous sodium hydrogen carbonate (200 mL of 1 M)
3. dry with materialdried (Na2SO4)
4. filtrationfiltered
5. customevaporated to dryness under reduced pressure
6. customto give the crude product which
7. customis recrystallised from ether-cyclohexane