Lithium Hydroxide → HCID 22933674, compound

HRID 1269962Notes

Reaction equation

HRID 1269962 reaction equation
[OH-].[Li+].CC1C(CC([O-])=[O:15])=CC(C)=C2C=1C=NN2.[CH3:18][C:19]1[C:27]([CH3:28])=[C:26]2[C:22]([CH:23]=[N:24][NH:25]2)=[CH:21][C:20]=1CC([O-])=O.[Cl-].[NH4+]>CO>[CH3:18][C:19]1[C:27]([CH3:28])=[C:26]2[C:22]([CH:23]=[N:24][NH:25]2)=[CH:21][C:20]=1[OH:15]

Participants

6

Reactant 4

HCID 3939Lithium HydroxideHCID 25517Ammonium ChlorideHCID 18447142HCID 18447142, compoundHCID 18447211HCID 18447211, compound

Product 1

HCID 22933674HCID 22933674, compoundYield 100%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A 2N-aqueous lithium hydroxide solution (28.6 ml, 57.2 mmol) was added to a solution of a mixture of (4,7-dimethyl-1H-indazol-5-yl)acetate and (6,7-dimethyl-1H-indazol-5-yl)acetate (approximately 1:1, 5.30 g, 26.0 mmol) in methanol (30 ml) under ice-cooling, and the resulting mixture was stirred at room temperature for 1.5 hours. A saturated aqueous ammonium chloride solution was poured into the reaction solution, followed by extraction with ethyl acetate, whereby a mixture of 4,7-dimethyl-1H-indazol-5-ol and 6,7-dimethyl-1H-indazol-5-ol (4.31 g, 100%) was obtained. To this mixture were added tetrahydrofuran (200 ml) and N-chlorosuccinimide (1.74 g, 13.0 mmol), and the resulting mixture was stirred at 50° C. for 3 hours. The reaction solution was poured into water to terminate the reaction, and was extracted with ethyl acetate. The extract solution was washed with a saturated aqueous sodium chloride solution, dried over sodium sulfate, and then distilled under reduced pressure to remove the solvent, whereby a crude product was obtained. The crude product was washed three times with methanol to obtain 4-chloro-6,7-dimethyl-1H-indazol-5-ol (440 mg). On the other hand, the solvent of the filtrate was distilled off under reduced pressure and then the residue was purified by a silica gel column chromatography (hexane/ethyl acetate=2:1) to obtain 4-chloro-6,7-dimethyl-1H-indazol-5-ol (980 mg, 1.42 g in total, 56%).

Workup

  1. temperaturecooling
  2. extractionfollowed by extraction with ethyl acetate, whereby
  3. additiona mixture of 4,7-dimethyl-1H-indazol-5-ol

Sources & evidence

ORD record
ord-6e425dfa7db1473caf47d60f70733d92
Source dataset
uspto-grants-2007_04
Patent number
US07199147B2

Reaction notes

Loading…