Iodine → 1-Methyl-4-(2-(4-acetamidophenoxy)acetyl)piperidine

Participants

Reaction Conditions

Reaction Steps

A crystal of iodine was added to 0.45 gm (18.7 mMol) magnesium turnings covered with 6 mL tetrahydrofuran. To this mixture were added 5-6 drops of dibromoethane and the mixture was heated with a heat gun to initiate the reaction. Once the iodine color disappeared, 2 mL (15 mMol) 1-methyl-4-chloropiperidine were added and heating continued for an additional 30 seconds. After the exothermic reaction no longer maintained reflux temperature, the reaction mixture was heated at reflux for 30 minutes and was then cooled to 0° C. To the cold mixture was added the previously prepared N-methyl-N-methoxy 2-(4-acetamidophenoxy)acetamide and the resulting mixture stirred for 30 minutes at 0° C. and then an additional hour after warming to room temperature. The reaction was quenched by the addition of water and the resulting mixture extracted well with ethyl acetate. The combined organic extracts were washed saturated aqueous ammonium chloride, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting residue was subjected to silica gel chromatography, eluting with dichloromethane containing 5% methanol. Fractions shown to contain product were combined and concentrated under reduced pressure to provide 0.90 gm (47%) of the desired ketone.

Provenance & Evidence