Methyl iodide → Tert-butyl 4-(3-(ethoxycarbonyl)phenyl)-3-methyl-2-oxopiperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

Potassium bis(trimethylsilyl)amide (14 g, 71 mmol) was mixed with 300 mL of THF in a 1000 mL flame-dried round bottomed flask and the resulting mixture was cooled to −78° C. tert-butyl 4-[3-(ethoxycarbonyl)phenyl]-2-oxopiperidine-1-carboxylate (22.5 g, 64.8 mmol) dissolved in 150 mL of THF was added slowly to the mixture, via an addition funnel, and the resulting reaction mixture was stirred at −78° C. for 30 min. Methyl iodide (12.1 mL, 195 mmol) was then added dropwise and the reaction mixture was allowed to stir at −78° C. for 4 h before being allowed to warm to room temperature overnight. The reaction was quenched with saturated ammonium chloride and extracted 3 times with ether. The combined ethereal layers were washed with brine and dried over MgSO4, filtered, and concentrated under reduced pressure. The product was purified by flash chromatography (10-20% EA/hexanes) to give 6.1 g of the trans racemate of tert-butyl 4-[3-(ethoxycarbonyl)phenyl]-3-methyl-2-oxopiperidine-1-carboxylate (26%).

Provenance & Evidence