Ethyl 5-fluoro-1H-pyrrolo[2,3-c]pyridine-2-carboxylate synthesis

Yield:920978-84-3 22%

Reaction Conditions:

with iron⁽⁰⁾;glacial acetic acid at 60 - 70; for 2 h;Inert atmosphere;

Steps:

1.ii Step ii.

The cherry-red solid (0.42g) from above was dissolved in AcOH (10 mL) and warmed to 60°C under nitrogen then powdered iron (0.72 g, 12.8 mmol) was added. The mixture was heated at 70°C under nitrogen. After 2 hours, the mixture was cooled to room temperature then diluted with water (25 mL). The resulting solid was filtered, rinsed with water and partially dried by suction. The solid was suspended in MeOH (20 mL), sonicated for 1 minute then filtered through plug of CELITE. The filtrate was evaporated under reduced pressure to give ethyl 5-fluoro-1H-pyrrolo[2,3-c]pyridine-2-carboxylate (0.31 g, 22% yield) as a tan solid. LCMS m/z found 209.1 [M+H]⁺; RT = 2.57 min (Method C); 1H NMR (400 MHz, DMSO-d₆) δ 12.51 (s, 1H), 8.48 - 8.43 (m, 1H), 7.35 - 7.30 (m, 1H), 7.19 - 7.15 (m, 1H), 4.38 (q, 2H), 1.35 (t, 4H).

References:

WO2021/229302,2021,A1 Location in patent:Page/Page column 144; 367-368