反应详情

To a stirred solution of intermediate (b), N-BOC-(R)-2-(4-hydroxybenzyl)morpholine (1.0 g, 3.41 mmol) in anhydrous N,N-dimethyl formamide (10 mL), under at atmosphere of nitrogen at room temperature was added N-bromosuccinimide (0.63 g, 3.58 mmol). The resulting solution was stirred at room temperature for 2 hrs and then poured into water (50 mL) and extracted with ethyl acetate (70 mL×2). Combined organic layers were washed with water (2×50 mL), brine (50 mL), dried (MgSO4), filtered and concentrated in vacuo. The material was concentrated onto sodium sulfate and purified by column chromatography (silica; 17% ethyl acetate/isohexane) to yield the desired intermediate (a), N-BOC-(R)-2-(3-bromo-4-hydroxybenzyl)morpholine, as a white solid (0.89 g).

1. extractionextracted with ethyl acetate (70 mL×2)
2. washCombined organic layers were washed with water (2×50 mL), brine (50 mL)
3. dry with materialdried (MgSO4)
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. concentrationThe material was concentrated onto sodium sulfate
7. custompurified by column chromatography (silica; 17% ethyl acetate/isohexane)