Ethanol → HCID 23122072, compound

Participants

Reaction Steps

To a stirred solution of N,N'-di-tert-butyloxycarbonylpiperazine-2-carboxylic acid (4.6 g, 0.013 mol), 1-(3-(dimethylamino)propyl)-3-ethylcarbodiimide hydrochloride (3.2 g, 0.016 mol), triethylamine (2.2 mL, 0.016 mol) and 4-pyrrolidinopyridine (0.23 g, 1.5 mmol) in CH2Cl2 (120 mL) was added ethanol (0.93 mL, 0.016 mol). The mixture was left stirring overnight, then the mixture was washed with water (2×50 mL), 5% aqueous acetic acid (2×300 mL) and water (2×50 mL). The organic phase was separated, dried (Na2SO4) and evaporated. The residue was chromatographed on silica gel, eluting with petrol:EtOAc (1:1) to give the ester (3.3 g, 72%) as a colourless oil. 1H NMR (360 MHz, CDCl3) δ 1.28 (3H, t, J=7.1 Hz), 1.44 (9H, s), 2.70-3.32 (3H, m), 3.70-4.12 (2H, m), 4.14-4.26 (2H, m), 4.46-4.76 (2H, m). MS (ES+) 359 (M+1).

Provenance & Evidence