反应详情

温度

-78 °C

A solution of 3.35 g (0.0167 mole) 5-bromo-2-hydroxybenzaldehyde in 15 ml dry tetrahydrofuran (HF) was cooled to -78° C. To this was added dropwise over seven minutes, a solution of 9.37 g (0.050 mole) cyclohexylmagnesium bromide (prepared by reaction of cyclohexylbromide with an equimolar amount of magnesium turnings in THF under anhydrous conditions) in THF (50 ml). The reaction mixture was stirred at -78° C. for 1.5 hours, then at -10° C. for another hour. The reaction was quenched by addition of 3.0 g (0.050 mole) acetic acid, the mixture allowed to warm slowly to room temperature and stirred for 70 hours. Evaporation of solvent gave a viscous oil which was partitioned between 500 ml ethyl acetate and 300 ml 1N hydrochloric acid. The organic layer was washed with saturated sodium bicarbonate (2×300 ml), brine, dried (MgSO4), filtered and solvent evaporated in vacuo to yield 7.0 g of product as a viscous oil. The oil was purified by silica gel chromatography, eluting with 4:1 hexane/ethyl acetate to obtain 3.7 g (78%) of product which crystallized upon standing, m.p. 110-113° C. M.S. m/e): 286, 284, 268, 266, 201 (base).

1. additionTo this was added dropwise over seven minutes
2. waitat -10° C. for another hour
3. temperatureto warm slowly to room temperature
4. stirringstirred for 70 hours
5. customEvaporation of solvent
6. customgave a viscous oil which
7. customwas partitioned between 500 ml ethyl acetate and 300 ml 1N hydrochloric acid
8. washThe organic layer was washed with saturated sodium bicarbonate (2×300 ml), brine
9. dry with materialdried (MgSO4)
10. filtrationfiltered
11. customsolvent evaporated in vacuo