Dimethylformamide → tert-butyl 3-[(dimethylamino)methylene]-4-oxotetrahydro-1(2H)-pyridinecarboxylate

Participants

Reaction Conditions

Reaction Steps

Tert-butyl-4-oxo-1-piperidinecarboxylate (10 g, 50 mmol) and N,N-dimethylformamide dimethyl acetal (7.3 mL, 55 mmol) were added to N,N-dimethylformamide (75 mL) under nitrogen gas and the mixture heated at 90° C. for 8 hours and then stirred for a further 16 hours at room temperature. The reaction mixture was concentrated under reduced pressure, and the residue partitioned between ethyl acetate (200 mL) and brine (200 mL). The aqueous phase was re-extracted with ethyl acetate (200 mL). The combined organic extracts were dried (Na2SO4) and concentrated under reduced pressure to give a brown oil that solidified on standing. Trituration with cyclohexane (20 mL) gave the title compound as a light brown solid (8.5 g, 67%).

Provenance & Evidence