Hydrochloric Acid → 1-Boc-3-bromo-5-nitro-1H-indazole

HRID 1983464Notes

Reaction equation

HRID 1983464 reaction equation
[Br:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([N+:11]([O-:13])=[O:12])[CH:9]=2)[NH:4][N:3]=1.[C:14](=O)([O:20]C(C)(C)C)[O:15][C:16]([CH3:19])([CH3:18])[CH3:17].O.Cl>CN(C)C1C=CN=CC=1.O1CCCC1>[Br:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([N+:11]([O-:13])=[O:12])[CH:9]=2)[N:4]([C:14]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:20])[N:3]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 10219638Carbonic acid, bis(1,1-dimethylethyl) esterHCID 178526490HCID 178526490, compound

Product 1

HCID 222608361-Boc-3-bromo-5-nitro-1H-indazole

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 24.0 g of 3-bromo-5-nitro-1H-indazole and 12.2 g of 4-(dimethylamino)pyridine in 50 ml tetrahydrofuran was added dropwise 23 ml of di-tert-butyl carbonate at room temperature. After stirring at room temperature for 30 minutes, the mixture was added with water, acidified by adding diluted hydrochloric acid and extracted with ethyl acetate. The organic layer was washed with water, dried over anhydrous magnesium sulfate and the solvent was evaporated. The residue was purified and separated by silica gel column chromatography (ethyl acetate:hexane=1:10), to give 20.5 g of the title compound as colorless needles.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe organic layer was washed with water
  3. dry with materialdried over anhydrous magnesium sulfate
  4. customthe solvent was evaporated
  5. customThe residue was purified
  6. customseparated by silica gel column chromatography (ethyl acetate:hexane=1:10)

Sources & evidence

ORD record
ord-0fc5bf00bd9c488a986d56a1bbfd35cc
Source dataset
uspto-grants-2009_06
Patent number
US07541376B2

Reaction notes

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