ethyl 5-carbamoyl-4-(3-fluoro-4-nitrophenyl)-1H-pyrrole-3-carboxylate → ethyl 5-cyano-4-(3-fluoro-4-nitrophenyl)-1H-pyrrole-3-carboxylate

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Reaction Steps

A solution of intermediate ethyl 5-(aminocarbonyl)-4-(3-fluoro-4-nitrophenyl)-1H-pyrrole-3-carboxylate (36.8 mg, 114.5 mmol) in POCl3 (500 mL) was heated to 70° C. for 2 h. TLC analysis indicated that there was complete conversion of starting material. Excess POCl3 was removed under reduced pressure and the remaining solids were poured over ice. The pH was adjusted to 8 using 5 N NaOH and the solution was filtered. The product was dried over night under reduced pressure to afford a light brown solid (33.85 g, 111.6 mmol) in 97% yield. 1H-NMR (DMSO-d6) δ 13.32 (br s, 1H), 8.21 (app t, J=8.4 Hz, 1H), 7.90 (s, 1H), 7.73 (dd, J=12.4, 2.0 Hz, 1H), 7.51 (m, 1H), 4.13 (q, J=7.2 Hz, 2H), 1.15 (t, J=7.2 Hz, 3H); HPLC RT=3.16 min.

Provenance & Evidence