反应详情

2 g of 4-bromo-3-chlorophenol dissolved in 20 cm3 of dimethylformamide are added to 480 mg of sodium hydride at 60% in oil, in 10 cm3 of dimethylformamide, followed by addition of a solution of 1.38 cm3 of benzyl chloride dissolved in 5 cm3 of dimethylformamide. The reaction medium is concentrated under reduced pressure and taken up in 100 cm3 of ethyl acetate. The organic phase is washed successively with 2×50 cm3 of water and with 50 cm3 of saturated sodium chloride solution, separated out after settling of the phases has taken place, dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (2 kPa; 50° C.) to give 3 g of crude product, which is purified by chromatography under an argon pressure of 50 kPa, on a column of silica gel (particle size 40-60 μm; diameter 2.5 cm), eluting with a cyclohexane/ethyl acetate mixture (90/10 by volume). The fractions containing the expected product are combined and evaporated under reduced pressure (2 kPa; 50° C.). 2.63 g of 1-bromo-2-chloro-4-(phenylmethoxy)benzene are obtained in the form of an orange-coloured oil which crystallizes.

1. concentrationThe reaction medium is concentrated under reduced pressure
2. washThe organic phase is washed successively with 2×50 cm3 of water and with 50 cm3 of saturated sodium chloride solution
3. customseparated out
4. dry with materialdried over magnesium sulphate
5. filtrationfiltered
6. concentrationconcentrated to dryness under reduced pressure (2 kPa; 50° C.)
7. customto give 3 g of crude product, which
8. customis purified by chromatography under an argon pressure of 50 kPa
9. washon a column of silica gel (particle size 40-60 μm; diameter 2.5 cm), eluting with a cyclohexane/ethyl acetate mixture (90/10 by volume)
10. additionThe fractions containing the expected product
11. customevaporated under reduced pressure (2 kPa; 50° C.)