Tetrahydrofuran → 6-Bromo-1-isopropyl-1H-indazole-4-carboxylic acid

HRID 85416Notes

Reaction equation

HRID 85416 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([C:14]([O-:16])=[O:15])[C:5]2[CH:6]=[N:7][N:8]([CH:11]([CH3:13])[CH3:12])[C:9]=2[CH:10]=1.O1CCCC1.[OH-].[Na+]>CO>[Br:1][C:2]1[CH:3]=[C:4]([C:14]([OH:16])=[O:15])[C:5]2[CH:6]=[N:7][N:8]([CH:11]([CH3:12])[CH3:13])[C:9]=2[CH:10]=1

Participants

5

Reactant 3

HCID 8028TetrahydrofuranHCID 14798Sodium HydroxideHCID 866773886-bromo-1-(1-methylethyl)-1H-indazole-4-carboxylate

Product 1

HCID 674654436-Bromo-1-isopropyl-1H-indazole-4-carboxylic acidYield 94%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of 6-bromo-1-(1-methylethyl)-1H-indazole-4-carboxylate (0.58 g, 1.952 mmol in methanol (12 mL) and tetrahydrofuran (3 mL) was added 3 N NaOH (3.25 mL, 9.76 mmol) via syringe and stirred for 3 h at RT. The volatiles were removed in vacuo then diluted with water and slowly acidifed with 1 N HCl to pH 4-5. The contents were extracted with 20% THF/EtOAc (3×). The combined organics were washed with brine, dried over MgSO4, filtered, and concentrated to give 6-bromo-1-(1-methylethyl)-1H-indazole-4-carboxylic acid (0.52 g, 94% yield). 1H NMR (400 MHz, DMSO-d6) d ppm 13.54 (s, 1H) 8.36-8.43 (m, 2H) 7.82 (d, J=1.52 Hz, 1H) 5.11 (quin, J=6.57 Hz, 1H) 1.48 (s, 3H) 1.47 (s, 3H); LC-MS(ES) [M+H]+ 283.4/285.2

Workup

  1. customThe volatiles were removed in vacuo
  2. additionthen diluted with water
  3. extractionThe contents were extracted with 20% THF/EtOAc (3×)
  4. washThe combined organics were washed with brine
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-d2482a4030234d1dae8332ef6cbfa8e8
Source dataset
uspto-grants-2014_09
Patent number
US08846935B2

Reaction notes

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