Benzyl Alcohol → 5-(Benzyloxy)-6-bromo-1H-indazole

HRID 2195511Notes

Reaction equation

HRID 2195511 reaction equation
[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([CH:6]=[N:7][NH:8]2)=[CH:4][C:3]=1[OH:11].[CH2:12](O)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.CCOC(/N=N/C(OCC)=O)=O.[NH4+].[Cl-]>C1COCC1.CCOC(C)=O>[CH2:12]([O:11][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][C:2]=1[Br:1])[NH:8][N:7]=[CH:6]2)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

8

Reactant 5

HCID 244Benzyl AlcoholHCID 11776TriphenylphosphineHCID 25517Ammonium ChlorideHCID 5462977Diethyl azodicarboxylateHCID 591599466-Bromo-1H-indazol-5-ol

Product 1

HCID 667670495-(Benzyloxy)-6-bromo-1H-indazoleYield 70.2%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent2×

Procedure

To a solution of 6-bromo-5-hydroxy-1H-indazole (5 g, 23.5 mmol) in THF (50 mL) is added benzyl alcohol (3.05 g, 28.2 mmol), PPh3 (7.39 g, 28.2 mmol) and diethylazodicarboxylate (4.46 mL, 28.2 mmol). After the reaction mixture is stirred at RT overnight, EtOAc (50 mL) and saturated aqueous NH4Cl (30 mL) are added. The organic phase is separated, dried over MgSO4, and concentrated. The residue is purified by silica gel column chromatography eluting with PE:EtOAc (4:1) to provide the product (5.0 g, 70.2% yield). MS (m/z): 303.0 (M+H).

Workup

  1. customThe organic phase is separated
  2. dry with materialdried over MgSO4
  3. concentrationconcentrated
  4. customThe residue is purified by silica gel column chromatography
  5. washeluting with PE

Sources & evidence

ORD record
ord-1f45e08fd8064a4d81ac9221de6ba3cb
Source dataset
uspto-grants-2012_12
Patent number
USRE043878E1

Reaction notes

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