Diisopropylethylamine → Benzyl 4-((3-chloropyrazin-2-yl)methylcarbamoyl)piperidine-1-carboxylate

Participants

Reaction Steps

A solution of C-(3-Chloropyrazin-2-yl)methylamine bis-hydrochloride (2.00 g, 0.0107 mol) and N,N-diisopropylethylamine (2.2 g, 0.017 mol) in DCM (27.0 mL) was treated with and N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (3.2 g, 0.017 mol), (1.5 g, 0.011 mol) and 1-[(benzyloxy)carbonyl]-4-piperidine carboxylic acid (3.8 g, 0.014 mol). The mixture was stirred at rt overnight then diluted with DCM (30 mL), washed with sat. NaHCO3 (20 mL) and brine (20 mL), then dried over Na2SO4 and concentrated in vacuo. The crude material thus obtained was chromatographed over silica gel eluting with EtOAc:hexane 1:1 yielding 3.38 g of the title compound. 1H NMR (400 MHz, CDCl3); δ 1.68-1.78 (m, 2H), 1.91-1.94 (m, 2H), 2.44 (m, 1H), 2.89-2.92 (m, 2H), 4.24-4.26 (m, 2H), 4.70 (d, J=4.8 Hz, 2H), 5.14 (s, 2H), 6.85 (br, 1H), 7.30-7.37 (m, 5H), 8.34 (d, J=2.8 Hz, 1H), 8.45 (d, J=2.8 Hz, 1H). MS (ES+): m/z 389.17 [MH+].

Provenance & Evidence