Cesium carbonate → methyl 3-bromo-1H-indazole-6-carboxylate

HRID 1047635Notes

Reaction equation

HRID 1047635 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:13]=[C:12]2[C:8]([CH:9]=[N:10][NH:11]2)=[CH:7][CH:6]=1)=[O:4].C(=O)([O-])[O-].[Cs+].[Cs+].[Br:20]Br>C(#N)C>[Br:20][C:9]1[C:8]2[C:12](=[CH:13][C:5]([C:3]([O:2][CH3:1])=[O:4])=[CH:6][CH:7]=2)[NH:11][N:10]=1

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 24408BromineHCID 286535methyl 1H-indazole-6-carboxylate

Product 1

HCID 178497093methyl 3-bromo-1H-indazole-6-carboxylateYield 99%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

6-(1H)-indazole carboxylic acid methyl ester (1.5688 g, 8.90 mmol) and cesium carbonate (4.38 g, 13.44 mmol) were dissolved in acetonitrile (89 ml) at 25° C. Bromine (0.554 ml, 10.75 mmol) was added and the reaction mixture was allowed to stir for 20 min. The reaction was stopped, quenched by addition of saturated aqueous sodium hydrogen carbonate (30 mL) and 10% aqueous sodium thiosulfate (30 mL), and the mixture extracted with ethyl acetate (3×50 mL). The combined organic phases were washed with saturated aqueous sodium chloride (1×50 mL), dried (sodium sulfate), filtered, and the solvent evaporated under reduced pressure. The title compound (2.241 g, 8.79 mmol, 99% yield) was recovered as a light orange/white solid. LC-MS: [M+1]=255.2.

Workup

  1. customquenched by addition of saturated aqueous sodium hydrogen carbonate (30 mL) and 10% aqueous sodium thiosulfate (30 mL)
  2. extractionthe mixture extracted with ethyl acetate (3×50 mL)
  3. washThe combined organic phases were washed with saturated aqueous sodium chloride (1×50 mL)
  4. dry with materialdried (sodium sulfate)
  5. filtrationfiltered
  6. customthe solvent evaporated under reduced pressure

Sources & evidence

ORD record
ord-9a524232e8d14a97b1e78e5c663309b2
Source dataset
uspto-grants-2013_10
Patent number
US08569512B2

Reaction notes

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