Dimethylformamide → Methyl 5-amino-2-phenylcyclopenta-1,3-dienecarboxylate

Participants

Reaction Steps

To a solution of methyl 3-phenyl-1H-pyrrole-2-carboxylate (2.50 g, 12.4 mmol) in DMF (25 mL) was added NaH (0.358 g, 14.9 mmol) and the reaction mixture was stirred for 45 min at room temperature. Monochloramine (0.15 M, 150 mL, 0.225 g, 4.40 mmol) was added via syringe. The reaction was stirred for 2 h and was quenched by the addition of saturated aqueous sodium thiosulfite. The reaction mixture was diluted with water and the aqueous portion extracted with ethyl acetate. The organic layer dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by column chromatography using CombiFlash (REDISEP®, neutral alumina, 40 g, 25% EtOAc/hexanes) to afford methyl 5-amino-2-phenylcyclopenta-1,3-dienecarboxylate (2.20 g, 82.0%). LCMS Condition B-38: retention time 1.79 min, [M+1]=217.0. 1H NMR (400 MHz, DMSO-d6) δ ppm 3.63 (s, 3H), 6.07 (d, J=2.8 Hz, 1H), 6.28 (s, 2H), 7.05 (d, J=2.8 Hz, 1H), 7.33-7.35 (m, 5H).

Provenance & Evidence