Iodine → 1-Benzyl-3-(3-methoxyphenyl)piperidine

Participants

Reaction Steps

3-Bromoanisole (14.824 g, 79.26 mmol) was dissolved in 160 mL of diethyl ether dried on Na. Approximately 10% of the solution of 3-bromoanisole in dry diethyl ether was added to magnesium (1.927 g, 79.27 mmol) and a few iodine crystals in a dried 500 mL three-necked flask in a nitrogen atmosphere while stirring. Almost instantly, H2 gas was visible. The brown mixture turned colourless. The remaining solution of 3-bromoanisole in dry diethyl ether was added drop wise. Gas forming was noticed during and after this. After 1 h, a lot of white precipitate was noticed. 1-Benzyl-3-piperidone (5.000 g, 26.42 mmol) was dissolved in 120 mL of dry diethyl ether and added to the reaction mixture drop wise at 30° C. The fine white/yellow precipitate turned more coarse and brownish. Stirring was continued at room temperature for 1 h. Then the suspension was poured in a Erlenmeyer flask and 150 mL of saturated NH4Cl solution was added. About 50 mL of ethylacetate was added to wash out the three-necked flask. The suspension was stirred for 5 min. The organic layer was separated and the aqueous layer was extracted three times with diethyl ether. The organic layers were collected, washed with brine and dried on NaSO4 overnight. The solution was filtered and the solvent evaporated. The residue (about 12.000 g) was extracted with ether once, the solvent evaporated. Yield: 7.6 g (32%). GCMS (EI): m/z 297 (M+), 206 (M−91), 177, 147, 134; GC (100-320° C., 15° C./min): 9.1 min.

Provenance & Evidence