Triethylamine → 4-tert-butoxycarbonyl-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester

Participants

Reaction Steps

To a solution of methyl 4H-furo[3,2-b]pyrrole-5-carboxylate (1.0 g, 6.06 mmol) in CH2Cl2 (10 ml) was added triethyl amine (1.85 g, 18.2 mmol) and DMAP (148 mg 1.22 mol). Then BOC2O (2.0 g, 9.1 mmol) was added. The resulting mixture was stirred overnight. After the reaction was complete as judged TLC analysis (10% EtOAc/hexane), the reaction mixture was washed with water and brine and dried over Na2SO4. After filtration, the filtrate was concentrated and the crude product was purified by silica gel chromatography (20% EtOAc in hexane) to give 4-tert-butoxycarbonyl-4H-furo[3,2-b]pyrrole-5-carboxylic acid methyl ester as a white solid (987 mg, 62%). 1H NMR (400 MHz, CDCl3) δ (ppm) 7.45 (d, J=1.47 Hz, 1H), 6.82 (s, 1H), 6.59 (s, 1H), 3.80 (s, 3H), 1.55 (s, 9H).

Provenance & Evidence