Benzyl Chloride → 3-Carbomethoxy-1,3-dibenzyl-4-piperidone

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-benzyl-4-oxo-piperidine-3-carboxylic acid methyl ester (5.14 g, 20.8 mmol) in DMF (130 mL) at 0° C. was added sodium hydride (60% by weight in mineral oil, 0.874 g, 21.8 mmol) in four portions over 0.5 h. After stirring at 0° C. for an additional 0.5 h, benzyl chloride (2.87 mL, 25.0 mmol) was added and the reaction mixture was allowed to stir for 14 h while warming to room temperature. The reaction mixture was partitioned between EtOAc and saturated aqueous sodium bicarbonate solution, the organic layer was removed and the aqueous layer was washed four times with EtOAc. The combined organic layers were dried over sodium sulfate, filtered and concentrated under vacuum. Purification by silica gel chromatography employing 0.5% MeOH/0.2% NH4OH/CH2Cl2 as the eluant afforded the compound of Example 200, Step A as a pale yellow oil (5.89 g): +APcI MS (M+1)+ 338; 1H NMR (400 MHz, CDCl3) δ: 7.09-7.39 (arom, series of m, 10H), 3.60 (s, 3H), 3.56 (d, 2H), 3.38 (m, 1H), 3.20 (d, 1H), 2.93 (m, 2H), 2.78 (m, 1H), 2.42 (m, 2H), 2.31 (m, 1H).

Provenance & Evidence