Triethylamine → (Azetidin-1-yl)(5-chloropyrazin-2-yl)methanone

Participants

Reaction Steps

Oxalyl chloride (1.55 mL, 17.48 mmol), followed by DMF (2 drops), was added to a mixture of 5-chloropyrazine-2-carboxylic acid (2.31 g, 14.57 mmol) in DCM (40 mL). The reaction was stirred at RT for 2 hours after which time the volatiles were removed in vacuo. The residue was taken up DCM (40 mL) and azetidine (1.08 mL, 16.03 mmol) and triethylamine (4.46 mL, 32.06 mmol) added. The mixture was stirred at RT for 72 hours. The volatiles were removed in vacuo and ethyl acetate (100 mL) added to the residue. The organics were washed with water (100 mL), citric acid (50 mL), saturated sodium bicarbonate solution (50 mL), brine (50 mL), dried (MgSO4), filtered and the solvent removed in vacuo to give a yellow solid. The residue was chromatographed on silica, eluting with a gradient of 50-100% ethyl acetate in iso-hexane, to give the desired compound as a yellow solid (2.38 g). 1H NMR δ (CDCl3): 2.35-2.42 (2H, m), 4.26 (2H, t), 4.67 (2H, t), 8.52 (1H, d), 9.09 (1H, d); m/z 198 (M+H)+.

Provenance & Evidence