Hydrochloric Acid → 1H-indazole-6-carboxylic acid

HRID 22660Notes

Reaction equation

HRID 22660 reaction equation
CC(C)([O-])C.[K+].C(S[N:12]=[N:13][C:14]1[CH:15]=[C:16]([CH:20]=[CH:21][C:22]=1[CH3:23])[C:17]([OH:19])=[O:18])(C)(C)C.Cl>CS(C)=O>[NH:13]1[C:14]2[C:22](=[CH:21][CH:20]=[C:16]([C:17]([OH:19])=[O:18])[CH:15]=2)[CH:23]=[N:12]1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 225913013-(Tert-butylthio)diazenyl-4-methylbenzoic acidHCID 23665647Potassium tert-butoxide

Product 1

HCID 162279381H-indazole-6-carboxylic acidYield 98.3%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent2×

Procedure

To a stirred solution of potassium tert-butoxide (8.14 g, 72.7 mmol) in DMSO (30 mL) is added a solution of 3-(tert-butylthio)diazenyl-4-methylbenzoic acid (1.85 g, 7.34 mmol) in DMSO (20 mL). The mixture is stirred overnight at rt. The mixture is diluted with ice-water, acidified with 1N aqueous HCl to a pH of about 5 to about 6 and extracted with EtOAc (3×). The combined organic layers are washed sequentially with water and brine, dried over MgSO4 and concentrated in vacuo to afford 1.17 g (98%) of 1H-indazole-6-carboxylic acid as a tan solid: IR (diffuse reflectance) 3171, 3135, 3067, 3014, 2950, 2889, 2865, 1685, 1326, 1308, 1240, 960, 945, 762, 740 cm−1; 1H NMR (400 MHz, DMSO-d6) δ 13.4, 13.0, 8.2, 8.2, 7.9, 7.7.

Workup

  1. extractionextracted with EtOAc (3×)
  2. washThe combined organic layers are washed sequentially with water and brine
  3. dry with materialdried over MgSO4
  4. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-5f73f35373f6452e8d01cbad08f860b3
Source dataset
uspto-grants-2005_02
Patent number
US06849620B2

Reaction notes

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