Iodine → 6-chloro-3-iodo-1H-pyrazolo[4,3-c]pyridine

Participants

Reaction Conditions

Reaction Steps

A flask was charged with 6-chloro-1H-pyrazolo[4,3-c]pyridine (3.0 g, 19.54 mmol), iodine (13.11 g, 51.7 mmol), KOH (3.29 g, 58.6 mmol), and DMF (60 mL). The mixture was heated at 40° C. for 16 h and then additional iodine (7.8 g, 30.7 mmol) and KOH (1.6 g, 28.4 mmol) were added. The mixture was heated at 70° C. for 3 h then quenched with 1 N Na2S2O3 and extracted with EtOAc. The organic phase was washed with water, brine, and dried over Na2SO4. After evaporation of volatiles DCM was added. A solid precipitated and was collected by filtration to yield 6-chloro-3-iodo-1H-pyrazolo[4,3-c]pyridine, which was carried onto the next step without further purification. MS ESI calc'd. for C6H4ClIN3 [M+1]+ 280. found 280.

Provenance & Evidence