Ethyl cyanoacetate → Tert-butyl 3-(1-cyano-2-ethoxy-2-oxoethyl)azetidine-1-carboxylate

Participants

Reaction Steps

To a solution of tert-butyl 3-oxoazetidine-1-carboxylate (3.4 g), diethyl 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (5.0 g) and ethyl cyanoacetate (2.2 g) in dimethylsulfoxide (40 mL) was added L-proline (460 mg), and the mixture was stirred at room temperature for 48 hr. The insoluble substance was removed by filtration, saturated aqueous ammonium chloride solution was added thereto, and the mixture was extracted with ethyl acetate. The obtained organic layer was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate) to give the title compound (4.3 g).

Provenance & Evidence