反应详情

At 0° C. under N2 atmosphere, to a solution of ethyl 4-hydroxy-4-methylpiperidine-1-carboxylate (283) (2.4 g, 12.8 mmol) in bromobenzene (20.1 g, 128 mmol) was added trifluoromethanesulfonic acid (19.2 g, 128 mmol). The resulting mixture was stirred at RT for 3 hours before being poured onto ice. The mixture was basified with 1N NaOH and extracted with DCM (20 mL×3). The combined organic layers were washed with brine, dried, concentrated in vacuo and subjected to silica flash column using 0 to 20% EtOAc in PE to give ethyl 4-(4-bromophenyl)-4-methylpiperidine-1-carboxylate (284) (3.4 g, 81%) as a light yellow oil.

1. additionbefore being poured onto ice
2. extractionextracted with DCM (20 mL×3)
3. washThe combined organic layers were washed with brine
4. customdried
5. concentrationconcentrated in vacuo