Methanol → Benzyl 4-formylpiperidine-1-carboxylate

Participants

Reaction Steps

A solution of 1-benzyl 4-methylpiperidine-1,4-dicarboxylate (10 g) in toluene (100 ml), under nitrogen, was cooled to −78° C. Then DIBAL-H (60.9 ml) was added dropwise at −78° C., and the mixture was stirred for 1 h at that temperature (TLC monitoring). Because the reaction was incomplete, a further 0.2 eq. of DIBAL-H was added and stirring was carried out for a further 30 min (TLC monitoring: some starting material and the corresponding alcohol were detectable). Methanol (40 ml) followed by sat. sodium chloride solution (40 ml) were added slowly to the reaction mixture at −78° C. The mixture was filtered over celite, and the solvent was removed under vacuum. The residue was extracted with ethyl acetate (3×75 ml), dried (Na2SO4) and concentrated under vacuum. The crude product so obtained was purified by column chromatography (silica gel, 20% ethyl acetate/hexane). Yield: 4.3 g (49%)

Provenance & Evidence