Iodine → 6-chloro-3-iodo-1H-pyrazolo[4,3-c]pyridine
Reaction equation
[Cl:1][C:2]1[N:7]=[CH:6][C:5]2[CH:8]=[N:9][NH:10][C:4]=2[CH:3]=1.[I:11]I.[OH-].[K+]>CN(C=O)C>[Cl:1][C:2]1[N:7]=[CH:6][C:5]2[C:8]([I:11])=[N:9][NH:10][C:4]=2[CH:3]=1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 40 °C
Procedure
A flask was charged with 6-chloro-1H-pyrazolo[4,3-c]pyridine (3 g, 19.54 mmol), iodine (13.11 g, 51.7 mmol), KOH (3.29 g, 58.6 mmol) and DMF (60 mL) (Note: heat generated during adding DMF). 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 and then quenched with 1N Na2S2O3 and extracted with EtOAc. The organic phase was washed with water, brine and dried (Na2SO4). After evaporation of volatiles DCM was added. A solid precipitated and filtrated off to yield 6-chloro-3-iodo-1H-pyrazolo[4,3-c]pyridine (3.2 g, 11.51 mmol, 59%), which was carried out in the next step without further purification. MS ESI calc'd. for C6H4ClIN3 [M+1]+ 280, found 280.
Workup
- temperatureThe mixture was heated at 70° C. for 3 h
- customquenched with 1N Na2S2O3
- extractionextracted with EtOAc
- washThe organic phase was washed with water, brine
- dry with materialdried (Na2SO4)
- customAfter evaporation of volatiles DCM
- additionwas added
- customA solid precipitated
- filtrationfiltrated off
Sources & evidence
- ORD record
- ord-f249308f8c744ece91acba74d07dfd67
- Source dataset
- uspto-grants-2015_05
- Patent number
- US09023865B2
Reaction notes
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