Dimethyl Carbonate → HCID 57571718, compound

Participants

Reaction Steps

Sodium methoxide (664 mg, 12 mmol) was added to a solution of the oxazolidinone from preparation 6 (1.17 g, 2.5 mmol) and dimethyl carbonate (1.03 mL, 12 mmol) in dichloromethane (15 mL) and the reaction was stirred at room temperature overnight. The reaction mixture was concentrated in vacuo and the residue was partitioned between ethyl acetate (50 mL) and water (30 mL). The aqueous layer was neutralised by the addition of 2M HCl (˜6 mL) and then concentrated in vacuo. The residue was triturated with acetonitrile (25 mL) and then filtered. Concentration of the filtrate gave (3S,4S)-1-benzyl-4-(5-chloropyridin-2-yl)pyrrolidine-3-carboxylic acid (123 mg, 16%) as yellow solid (see preparation 8 for spectroscopic data). The ethyl acetate layer was dried (MgSO4) and evaporated. Purification of the residue by column chromatography (silica), eluting with ethyl acetate/pentane 2:8, increasing polarity to 2:3 gave the title compound (371 mg, 45%) as a colourless oil. 1H NMR (CDCl3, 400 MHz) δ2.71 (1H, t), 2.97 (1H, t), 3.05 (2H, m), 3.23 (1H, m), 3.63 (5H, m), 3.82 (1H, q), 7.15-7.35 (6H, m), 7.55 (1H, d), 8.46 (1H, s); LRMS (APCI+) 331 [MH+].

Provenance & Evidence