To a solution of tert-butyl (4E and 4Z)-4-(cyanomethylidene)-3-fluoropiperidine-1-carboxylate (800 mg, 3.33 mmol) in MeCN (10 mL) were added 3-amino-1H-pyrazole-4-carboxamide (350 mg, 2.78 mmol) and DBU (0.837 mL, 5.55 mmol). The solution was stirred at ambient temperature for 16 hours. The reaction mixture was diluted with EtOAc and washed with brine, dried over anhydrous MgSO4, filtered, and concentrated in vacuo. The oily residue was purified by MPLC on silica gel (0-100% EtOAc/hexanes) to afford the title compound as a mixture of diastereomers. LRMS (ESI) calc'd for C16H23FN6O3 [M+H]+: 367. Found: 367.
