Methyl iodide → 6-Bromo-1,5-dimethyl-1H-indazole

HRID 1524235Notes

Reaction equation

HRID 1524235 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[CH3:11].[H-].[Na+].CI.[CH3:16]C(=O)OCC.[Cl-].[Na+].O>C1COCC1>[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([CH:6]=[N:7][N:8]2[CH3:16])=[CH:4][C:3]=1[CH3:11].[Br:1][C:2]1[C:3]([CH3:11])=[CH:4][C:5]2[C:9]([CH:10]=1)=[N:8][N:7]([CH3:16])[CH:6]=2

Participants

7

Reactant 4

HCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 247292646-Bromo-5-methyl-1H-indazoleHCID 131718255Brine ethyl acetate

Product 2

HCID 441194616-Bromo-1,5-dimethyl-1H-indazoleHCID 44119472HCID 44119472, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 6-bromo-5-methyl-1H-indazole (31, 211 mg, 1 mmol) in 5 ml dry THF was carefully added sodium hydride (200 mg, 60%). The suspension was stirred at r.t for 2 h before addition of methyl iodide (93 μl, 1.5 eq). After stirring at r.t. for 3 h, the reaction mixture was worked up with EA/brine. Org. phase was dried over sodium sulfate, concentrated and then subjected to silica gel column chromatography (0-50%-100% B; A: hexane; B: 50% EA in hexane) to give 101.4 mg of 6-bromo-1,5-dimethyl-1H-indazole (32) as white solid (yield: 45.0%; purity>95%) and 99.9 mg of 6-bromo-2,5-dimethyl-2H-indazole (33) as white solid (yield: 44.4%; purity>95%).

Workup

  1. dry with materialphase was dried over sodium sulfate
  2. concentrationconcentrated

Sources & evidence

ORD record
ord-69fdc08e7780404697407d2ddabb2e8f
Source dataset
uspto-grants-2015_07
Patent number
US09079891B2

Reaction notes

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