Hydrochloric Acid → 2-methyl-6-nitro-2H-indazole-3-carboxylic acid

HRID 1510331Notes

Reaction equation

HRID 1510331 reaction equation
CN1C2C(=CC=C([N+]([O-])=O)C=2)C(C(OC)=O)=N1.[CH3:18][N:19]1[C:27]([C:28]([O:30]C)=[O:29])=[C:26]2[C:21]([CH:22]=[C:23]([N+:32]([O-:34])=[O:33])[CH:24]=[CH:25]2)=[N:20]1.[OH-].[Na+].Cl>C(O)C.O>[CH3:18][N:19]1[C:27]([C:28]([OH:30])=[O:29])=[C:26]2[C:21]([CH:22]=[C:23]([N+:32]([O-:34])=[O:33])[CH:24]=[CH:25]2)=[N:20]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 59334978methyl 2-methyl-6-nitro-2H-indazole-3-carboxylateHCID 59335127Methyl 1-methyl-6-nitro-1H-indazole-3-carboxylate

Product 1

HCID 593348962-methyl-6-nitro-2H-indazole-3-carboxylic acid

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

670 mg of a mixture of methyl 1-methyl-6-nitro-1H-indazole-3-carboxylate and methyl 2-methyl-6-nitro-2H-indazole-3-carboxylate (Example XX) are dissolved in 20 ml of ethanol, combined with 10 ml 1 M sodium hydroxide solution and stirred for 2 hours. Then 10 ml of 1 M hydrochloric acid are added, the mixture is diluted with water and the precipitated solid is suction filtered. Then the solid is dissolved in dichloromethane/methanol 90:10. After drying with magnesium sulphate the solvents are eliminated in vacuo and the residue is dried in vacuo. 640 mg of a mixture of 1-methyl-6-nitro-1H-indazole-3-carboxylic acid and 2-methyl-6-nitro-2H-indazole-3-carboxylic acid is obtained which is further reacted directly in Example XV (1) or in XV (2), respectively.

Workup

  1. filtrationfiltered
  2. dissolutionThen the solid is dissolved in dichloromethane/methanol 90:10
  3. dry with materialAfter drying with magnesium sulphate the solvents
  4. customthe residue is dried in vacuo

Sources & evidence

ORD record
ord-e39a75dcaacc46ea970ac2a23000d164
Source dataset
uspto-grants-2012_07
Patent number
US08211923B2

Reaction notes

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