Dibromomethane → 1-tert-Butoxycarbonyl-4-phenyl-4-[1-(3,5-bis(trifluoromethyl)phenyl) vinyloxymethyl]piperidine

Participants

Reaction Conditions

Reaction Steps

Titanium tetrachloride (1.06 g) was added to cooled (0° C.) stirred tetrahydrofuran under a dry nitrogen atmosphere. After the exotherm had subsided the solution was allowed to warm to room temperature and tetramethylethylene diamine (1.69 g) added followed 15 minutes later by freshly activated zinc dust (819 mg). The resulting mixture was stirred for 30 minutes at room temperature at which point dibromomethane (0.21 ml) and the compound of step (b) above (716 mg) were added. The reaction was allowed to proceed for 18 hours at room temperature. After this time the reaction was quenched with saturated K2CO3 (7 ml) and diluted with diethyl ether. The resulting black suspension was filtered through a plug of grade III neutral alumina, eluting with 1 % triethylamine/diethyl ether. The filtrate was dried over MgSO4, filtered and the solvent removed under reduced pressure. The residual oil was purified by chromatography on silica gel (10% ethyl acetate/n-hexane) to afford the title compound. 1H NMR (360 MHz, CDCl3) δ 1.2 (9H, s), 1.95 (2H, m), 2.38 (2H, m), 3.05 (2H, m), 3.8 (2H, s), 3.95 (2H, m), 4.21 (1H, d, J=1.0 Hz), 4.63 (1H, d, J=1.0 Hz), 7.1-7.3 (5H, m), 7.7 (1H, s), 7.76 (2H, s).

Provenance & Evidence