Trifluoroacetic acid → 3,3-Dimethylpiperidin-4-one

Participants

Reaction Steps

The 3,3-dimethyl-4-oxo-piperidine-1-carboxylic acid tert-butyl ester thus prepared (450 mg, 1.97 mmol) was dissolved in methylene chloride (10 mL). Trifluoroacetic acid was added (305 uL) and the resulting solution stirred at room temperature 2 h. Additional trifluoroacetic acid was added (300 uL) and the reaction stirred at room temperature 3 days. The pale yellow solution was concentrated to afford an oily residue, which was triturated with ether. The solids were collected by suction filtration and dried in vacuo. 3,3-Dimethyl-piperidin-4-one was isolated and used as its trifluoroacetic acid salt (381 mg, 80%). 1H-NMR (d6-DMSO, 300 MHz) δ 3.44-3.33 (m, 4H), 2.63-2.57 (m, 2H), 1.11 (s, 6H).

Provenance & Evidence