反应详情

A solution of 2.4 mL (46 mmol) of Br2 in 45 mL of CHCl3 was added dropwise over 1 h to a chilled, stirring solution of 9.66 g (29 mmol) of 3′,5′-dibenzyloxyacetophenone (45) in 40 mL of CHCl3. The resulting solution was allowed to warm to room temperature over 1 hour with good stirring, then poured into 100 mL of cold H2O and transferred to a separatory funnel where the CHCl3 fraction was isolated, washed with brine solution, dried (Na2SO4), filtered, and concentrated to 10.8 g. This material was applied to 500 g of silica gel, eluting with CHCl3 to obtain 2.65 g (22%) of compound 46 as a white solid. 1H NMR (CDCl3) δ 4.39 (s, 2H), 5.08 (s, 4H), 6.85 (t, 1H, J=2.1 Hz), 7.20 (d, 2H, J=2.4 Hz), 7.31-7.44 (m, 10H).

1. customtransferred to a separatory funnel
2. washwashed with brine solution
3. dry with materialdried (Na2SO4)
4. filtrationfiltered
5. concentrationconcentrated to 10.8 g
6. washeluting with CHCl3