Diethyl Malonate → Diethyl 5H-Cyclopenta[b]pyridine-6,6(7H)-dicarboxylate

Participants

Reaction Steps

Sodium metal (0.345 g, 15.0 mmol) is dissolved in ethanol (20 ml) and diethyl malonate (0.713 g, 4.70 mmol) is added, followed by a suspension of 2,3-bis(chloromethyl)pyridine hydrochloride (Org. Process Res. Dev., 2002, 6, 938; 1.0 g, 4.70 mmol) in ethanol (15 ml) over 5 minutes. The reaction is heated to reflux for 5 hours, cooled to ambient temperature and filtered. The filtrate is evaporated, taken into water and extracted with ethyl acetate. The combined organic phases are washed with brine, dried (MgSO4) and evaporated. The crude product is purified by flash column chromatography (3:1-2:1 isohexanes-EtOAc gradient) to afford 5,7-dihydro-[1]pyrindine-6,6-dicarboxylic acid diethyl ester, MH+264.

Provenance & Evidence