Methanol → Benzyl 4-formylpiperidine-1-carboxylate

A solution of 1-benzyl 4-methyl piperidine-1,4-dicarboxylate (10 g) in toluene (100 ml) under nitrogen was cooled to −78° C. DIBAL-H (60.9 ml) subsequently was added dropwise at −78° C., and the mixture was stirred at this temperature for 1 h (TLC control). Because the reaction was incomplete, a further 0.2 eq of DIBAL-H was added and the mixture was stirred for a further 30 min (TLC control: some educt and the corresponding alcohol were to be detected). 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 in vacuo. The residue was extracted with ethyl acetate (3×75 ml) and the extract was dried (Na2SO4) and concentrated in vacuo. The crude product obtained in this way was purified by column chromatography (silica gel, 20% ethyl acetate/hexane). Yield: 4.3 g (49%)

1. stirringthe mixture was stirred for a further 30 min (TLC control
2. additionwere added slowly to the reaction mixture at −78° C
3. filtrationThe mixture was filtered over Celite
4. customthe solvent was removed in vacuo
5. extractionThe residue was extracted with ethyl acetate (3×75 ml)
6. dry with materialthe extract was dried (Na2SO4)
7. concentrationconcentrated in vacuo

ORD record

ord-f521aa4268894751885d2a26334e017d

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08119805B2