Potassium Carbonate → Tert-butyl 4-(6-chloroquinolin-2-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2,6-dichloroquinoline (1.5 g, 7.6 mmol) in DMF (50 ml) was added tert-butyl piperazine-1-carboxylate (7.1 g, 38.1 mmol, 5 eq), and potassium carbonate (2.1 g, 15.1 mmol, 2 eq). The mixture was stirred for 4 hours at 140° C. and then quenched by the addition of water (300 ml) and then extracted with ethyl acetate (3×100 ml). The organic layers were combined, washed with saturated aqueous sodium chloride (3×300 ml), dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum to give a residue. The crude material was purified by silica gel chromatography using 1-10% ethyl acetate in petroleum ether to elute. The product-containing fractions were combined and concentrated under vacuum to afford tert-butyl 4-(6-chloroquinolin-2-yl)piperazine-1-carboxylate as a light yellow solid (1.6 g, 61%). (ES, m/z): [M+H]+ 348; 1H NMR (300 MHz, DMSO): δ 8.03 (d, J=9.3 Hz, 1H), 7.81 (d, J=2.1 Hz, 1H), 7.50-7.58 (m, 2H), 7.29 (d, J=9.3 Hz, 1H), 3.68-3.71 (t, J=5.1 Hz, 4H), 3.43-3.47 (t, J=4.5 Hz, 4H), 1.43 (s, 9H).

Provenance & Evidence