Benzyl chloroformate → Benzyl 4-oxopiperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of piperidin-4-one hydrochloride (32 g, 0.23 mol) in tetrahydrofuran (320 ml, 10×) was added K2CO3 (64.2 g) dissolved in water (160 ml) at room temperature. The mixture was cooled to 0-5° C. and then Cbz chloride (50%) (74.28 ml, 1.1 eq.) was added dropwise. The reaction mixture was warmed to room temperature and stirred for 1-2 h. Progress of the reaction was monitored by TLC (30% ethyl acetate/hexane). Upon disappearance of the starting material the mixture was filtered and the layers were separated. The aqueous layer was extracted with ethyl acetate (2×300 ml) and the combined organic layers were dried over sodium sulfate and concentrated under reduced pressure. The crude product was purified by column chromatography (silica, 12% ethyl acetate/hexane). Yield: 40.7 g (74%)

Provenance & Evidence