130473-26-6

130473-24-4

130473-26-6

The general procedure for the synthesis of 1H-pyrrolo[2,3-c]pyridine-5-carbaldehyde using the compound (CAS: 130473-24-4) as starting material was as follows: C173 (800 mg, 4.21 mmol) was dissolved in 44 mL of 10% aqueous acetonitrile solution. Subsequently, p-toluenesulfonic acid (630 mg, 3.3 mmol) was added and the reaction mixture was heated to reflux and maintained for 5 hours. After completion of the reaction, the mixture was cooled to room temperature and subsequently concentrated under vacuum. The concentrated residue was diluted by adding 15 mL of saturated NaHCO3 solution to the concentrated residue. The resulting light yellow solid product was collected by filtration, washed with water and dried to give the final 1H-pyrrolo[2,3-c]pyridine-5-carbaldehyde (C174) in 81% yield. High resolution mass spectrometry (FAB) analysis results: calculated value C8H6N2O + H [M+H]+: 147.0558, measured value: 147.0564.