Potassium Carbonate → Tert-butyl 4-(2-chloro-4-cyanophenyl)piperazine-1-carboxylate

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Reaction Steps

Tert-Butyl piperazine-1-carboxylate (0.931 g, 5 mmol) and 3-chloro-4-fluorobenzonitrile (0.785 g, 5.00 mmol) were combined, K2CO3 (0.898 g, 6.50 mmol) was added and the reaction mixture was stirred at 90° C. for 1d. The mixture was triturated with ethyl acetate (3×5 mL) and the combined organic extracts were filtered. This was concentrated down to about 5-10 mL and subjected to flash column chromatograhy on silica gel (120 g SiO2, hexanes:ethyl acetate 1:0 to 4:1) to afford tert-butyl 4-(2-chloro-4-cyanophenyl)piperazine-1-carboxylate (1.264 g, 3.93 mmol, 79% yield) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ (ppm): 1.42 (s, 9H) 3.00-3.09 (m, 4H) 3.42-3.53 (m, 4H) 7.25 (d, J=8.59 Hz, 1H) 7.77 (dd, J=8.34, 2.02 Hz, 1H) 7.97 (d, J=2.02 Hz, 1H); [M+H] calc'd for C16H20ClN3O2, 322; found, 322.

Provenance & Evidence