1033772-22-3

7677-24-9

1033772-21-2

1033772-22-3

General procedure for the synthesis of 1H-pyrazolo[4,3-b]pyridine-5-carbonitrile from trimethylcyanosilane (TMSCN) and 4-hydroxy-1-[[2-(trimethylmethylsilyl)ethoxy]methyl]-1H-pyrazolo[4,3-b]pyridinium (CAS: 1033772-21-2, 1.59 g, 6 mmol): TMSCN ( 1.13 mL, 9 mmol) was added to a solution of 4-hydroxy-1-[[2-(trimethylsilyl)ethoxy]methyl]-1H-pyrazolo[4,3-b]pyridinium in dichloromethane (DCM, 130 mL). The reaction mixture was stirred at room temperature for 5 minutes before N,N-dimethylcarbamoyl chloride ((Me)2N(C(O)Cl, 0.83 mL, 9 mmol) was added. The reaction mixture was continued to be stirred at room temperature for 4 days. Upon completion of the reaction, the reaction mixture was diluted with DCM and subsequently washed with brine to concentrate the organic phase. Finally, the target product 1H-pyrazolo[4,3-b]pyridine-5-carbonitrile (1 g, 61% yield) was purified by column chromatography.