Acetic Acid → TERT-BUTYL 4-(1-CYANO-2-ETHOXY-2-OXOETHYLIDENE)PIPERIDINE-1-CARBOXYLATE

Participants

Reaction Steps

Ethyl cyanoacetate (11.0 mL, 126 mmol), ammonium acetate (0.976 g, 12.6 mmol) and acetic acid (0.715 mL, 12.6 mmol) were added to a solution of tert-butyl 4-oxopiperidine-1-carboxylate 8-1 (25.0 g, 126 mmol) in 200 mL of benzene at ambient temperature. After stirring at reflux with azeotropic removal of water (Dean-Stark apparatus), the reaction mixture was cooled to ambient temperature and diluted with ethyl acetate (500 mL). The organics were washed with saturated aqueous sodium bicarbonate, brine, dried (magnesium sulfate), and concentrated in vacuo to give a crude residue. Purification of the crude residue by recrystallization from 10% ethyl acetate/hexanes afforded 8-2 as a white crystalline solid.

Provenance & Evidence