Lithium Hydroxide → 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-1H-pyrazole-3-carboxylic acid

HRID 532242Notes

Reaction equation

HRID 532242 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:13]([C:14]2[CH:19]=[CH:18][C:17]([I:20])=[CH:16][CH:15]=2)=[C:12]([CH3:21])[C:11]([C:22]([O:24]CC)=[O:23])=[N:10]1.[OH-].[Li+]>C1COCC1.CO.O>[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:13]([C:14]2[CH:19]=[CH:18][C:17]([I:20])=[CH:16][CH:15]=2)=[C:12]([CH3:21])[C:11]([C:22]([OH:24])=[O:23])=[N:10]1

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 66761442ethyl 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-1H-pyrazole-3-carboxylate

Product 1

HCID 667612051-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-1H-pyrazole-3-carboxylic acid

Reagents, catalysts & solvents 1

HCID 21892291Methanol tetrahydrofuran waterSolvent

Procedure

The ester (10 g, 19.9 mmoles) obtained from step C was taken in 500 ml 1 neck flask and to it 300 ml of 7:2:1 mixture of THF-methanol-water along with solid lithium hydroxide (2.5 g, 104.6 mol) was added. The mixture was refluxed for 12 hours. The solvents were removed totally and to the residue 200 ml of DCM was added. To that 100 ml of water was added and the mixture was acidified to pH ˜2 using concentrated HCl. The organic layer was separated, washed with 100 ml of brine, dried over sodium sulphate and concentrated to give the acid. This was taken directly to the next step (9.4 g, 100%).

Workup

  1. additionwas added
  2. temperatureThe mixture was refluxed for 12 hours
  3. customThe solvents were removed totally and to the residue 200 ml of DCM
  4. additionwas added
  5. additionTo that 100 ml of water was added
  6. customThe organic layer was separated
  7. washwashed with 100 ml of brine
  8. dry with materialdried over sodium sulphate
  9. concentrationconcentrated
  10. customto give the acid

Sources & evidence

ORD record
ord-0428970fbcc2462ba92a25d56858b6c7
Source dataset
uspto-grants-2014_10
Patent number
US08853205B2

Reaction notes

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