Compound 59 (CAS:1001070-28-5, 2.58 g, 12.4 mmol) was taken as raw material and dissolved in 50 mL of methanol and 20 mL of 2N sodium hydroxide solution. The reaction mixture was stirred at room temperature for 30 minutes. After the reaction was completed, ethyl acetate was added to the mixture for extraction. The organic layer was washed with 5% aqueous sodium bicarbonate solution and subsequently dried over anhydrous sodium sulfate. The dried organic phase was filtered and concentrated to afford 6-fluoro-1H-pyrrolo[2,3-b]pyridine (6-fluoro-7-azaindole, compound 44) as a semi-solid (1.68 g, 12.3 mmol, 99% yield). The product was confirmed by 1H-NMR (400 MHz, CDCl3): δ 9.6 (broad single peak, 1H), 7.95 (broad triple peak, J=8Hz, 1H), 7.31-7.27 (multiple peaks, 1H), 6.75 (double dichotomous peaks, J=8Hz, 2Hz, 1H), 6.55-6.50 (multiple peaks, 1H). Thin-layer chromatography (TLC) analysis showed an Rf value of 0.34 using ether/petroleum ether (1/1) as the unfolding agent.Liquid chromatography-mass spectrometry (LCMS) analysis: retention time (Rt) of 1.39 min, [M+H]+=137.
![1H-Pyrrolo[2,3-b]pyridine-1-carboxylic acid, 6-fluoro-, ethyl ester](/CAS/GIF/1001070-28-5.gif)
