Potassium Carbonate → tert-Butyl 4-(cyanomethylidene)piperidine-1-carboxylate

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Reaction Steps

Add diethyl cyanomethylphosphonate (5.33 g, 4.88 mL, 30.11 mmol) to potassium carbonate (3.47 g, 25.09 mmol) in dry THF (10 mL) and stir at room temperature for 15 min., then heat under reflux for 15 min. To this mixture add 4-oxopiperidine-1-carboxylic acid t-butyl ester (5.00, 25.09 mmol) and heat under reflux under nitrogen for 24 hr., allow to cool to room temperature and stand overnight. Pour the reaction mixture into aqueous potassium carbonate solution (10%, 80 mL) and extract the resultant mixture with ethyl acetate (2×50 mL). Combine the organics, dry (MgSO4) and evaporate in vacuo to give 4-cyanomethylenepiperidine-1-carboxylic acid t-butyl ester as a liquid which solidifies on standing (5.39 g, 96.6%). NMR (δ-CDCl3) 1.5 (s, 9H), 2.4 (m, 2H), 2.6 (m, 2H), 3.5 (m, 4H), 5.2 (s, 1H).

Provenance & Evidence