反应详情

A solution of 2-(4-bromo-phenyl)-4-isopropyl-oxazole-5-carbaldehyde (14.4 g, 84.9 mmol) in THF (300 mL) is cooled to −78° C. and treated dropwise with methyl magnesium bromide (25 mL, 75 mmol, 3M Et2O). After 1 h, more methyl magnesium bromide (12 mL, 36 mmol) is added. The reaction mixture is stirred 1.5 h, and saturated NH4Cl solution (10 ml) is added dropwise. The mixture is partitioned between saturated NH4Cl solution (10 ml), 1N HCl (25 mL), and Et2O (300 mL). The organic layer is washed with brine (150 mL), dried (Na2SO4), and concentrated. The crude product is purified by silica gel flash chromatography using hexanes:ethyl acetate (9:1 to 5:1) to give an offwhite solid (9.5 g, 63%).

1. customThe mixture is partitioned between saturated NH4Cl solution (10 ml), 1N HCl (25 mL), and Et2O (300 mL)
2. washThe organic layer is washed with brine (150 mL)
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated
5. customThe crude product is purified by silica gel flash chromatography