Triethylsilane → N-benzyloxycarbonyl-4-(4,5,6,7-tetrafluoroindol-3-yl)piperidine

Participants

Reaction Steps

To a solution of N-benzyloxycarbonyl-4-piperidone (20.2 g, 90.6 mmol) in methylene chloride (600 ml) at 0° C. was added trimethylsilyl trifluoromethanesulfonate (35.1 ml, 181.2 mmol) followed by the slow dropwise addition of a solution of 4,5,6,7-tetrafluoroindole (17.1 g, 90.6 mmol) in methylene chloride (300 ml) over 2.5 h. After 1.5 h, triethylsilane (57.9 ml, 362.4 mmol) was added and the reaction was allowed to warm to RT over 30 min. The reaction mixture was quenched with sat. sodium bicarbonate and the separated organic layer was dried over MgSO4 and concentrated in vacuo. The residue was partitioned between 50% acetonitrile/hexanes (1400 ml) and the separated acetonitrile layer was concentrated in vacuo. The solid residue was recrystallized from absolute EtOH to afford N-benzyloxycarbonyl-4-(4,5,6,7-tetrafluoroindol-3-yl)piperidine (66%) as a white solid.

Provenance & Evidence