660406-84-8

GENERAL STEPS: Potassium tert-butoxide (69 g, 616 mmol) was added batchwise to a mixed solution of tetrahydrofuran (1 L) and acetonitrile (53 mL, 1027 mmol) of methyl 1-tert-butyloxycarbonyl-4-piperidinecarboxylate (50 g, 206 mmol) under ice-bath cooling conditions. The reaction mixture was gradually warmed to room temperature and stirred for 1 hour. Subsequently, the reaction mixture was slowly poured into saturated aqueous ammonium chloride solution (2 L) to terminate the reaction. The aqueous phase was extracted with ethyl acetate (3 x 500 mL) and the organic phase was combined. The organic phase was washed with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the light yellow oily product tert-butyl 4-(2-cyanoacetyl)piperidine-1-carboxylate (40 g, 77% yield). The product was detected by thin layer chromatography (TLC) with the unfolding agent ratio of petroleum ether/ethyl acetate=2:1 and Rf value of 0.5.

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