276862-85-2

272-49-1

100-97-0

276862-85-2

General procedure for the synthesis of 4-azaindole-3-carbaldehyde from 4-azaindole and hexamethylenetetetramine: A mixture of 4-azaindole (0.500 g, 4.223 mmol), hexamethylenetetetramine (0.890 g, 6.348 mmol), and acetic acid (3.630 mL, 63.45 mmol) in water (9 mL) was heated and refluxed for 4 hours. After completion of the reaction, the reaction mixture was cooled to room temperature and concentrated under reduced pressure. The target product 4-azaindole-3-carbaldehyde (0.550 g, 89% yield) was purified by silica gel column chromatography using a gradient elution of dichloromethane with methanol (2% to 4% methanol). The results of mass spectrometry analysis: ESI/APCI(+) m/z: 147 [M+H]+; ESI/APCI(-) m/z: 145 [M-H]-.