Sodium Nitrite → 4-chloro-7-methoxy-1H-pyrazolo[4,3-c]pyridine
Reaction equation
[N:1]([O-])=O.[Na+].[Cl:5][C:6]1[C:11]([CH3:12])=[C:10]([NH2:13])[C:9]([O:14][CH3:15])=[CH:8][N:7]=1>O.C(O)(=O)C>[Cl:5][C:6]1[C:11]2[CH:12]=[N:1][NH:13][C:10]=2[C:9]([O:14][CH3:15])=[CH:8][N:7]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 75 °C
Procedure
A solution of sodium nitrite (98%, 326 mg, 4.63 mmol) in water (0.6 mL) was added to a solution of C4 (200 mg, 1.16 mmol) in acetic acid (8 mL), and the reaction mixture was heated at 75° C. for 1 hour. After the reaction mixture had cooled to room temperature, it was concentrated in vacuo, diluted with saturated aqueous sodium bicarbonate solution, and extracted with ethyl acetate. The combined organic layers were washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. Silica gel chromatography (Gradient: 25% to 50% ethyl acetate in heptane) provided the product as a yellow solid. Yield: 140 mg, 0.763 mmol, 66%. LCMS m/z 184.0 [M+H+]. 1H NMR (400 MHz, CDCl3) δ 8.17 (s, 1H), 7.74 (s, 1H), 4.06 (s, 3H).
Workup
- temperatureAfter the reaction mixture had cooled to room temperature
- concentrationit was concentrated in vacuo
- additiondiluted with saturated aqueous sodium bicarbonate solution
- extractionextracted with ethyl acetate
- washThe combined organic layers were washed with saturated aqueous sodium chloride solution
- dry with materialdried over magnesium sulfate
- filtrationfiltered
- concentrationconcentrated under reduced pressure
Sources & evidence
- ORD record
- ord-31ccca9ee4c4403b8381c5710ae5ccca
- Source dataset
- uspto-grants-2014_09
- Patent number
- US08822494B2
Reaction notes
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