Lithium Hydroxide → 4,5-Diphenylisoxazole-3-carboxylic acid

HRID 1804500Notes

Reaction equation

HRID 1804500 reaction equation
[C:1]1([C:7]2[C:8]([C:18]([O:20]C)=[O:19])=[N:9][O:10][C:11]=2[C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[Li+].[OH-]>CO.C1COCC1.O>[C:1]1([C:7]2[C:8]([C:18]([OH:20])=[O:19])=[N:9][O:10][C:11]=2[C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

6

Reactant 2

HCID 3939Lithium HydroxideHCID 13524801Methyl 4,5-diphenylisoxazole-3-carboxylate

Product 1

HCID 585372184,5-Diphenylisoxazole-3-carboxylic acidYield 100%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a thick suspension of methyl 4,5-diphenylisoxazole-3-carboxylate (306 mg, 1.09 mmol) in MeOH (8 mL), THF (2 mL) and water (2 mL) at rt was added LiOH, hydrate (46.0 mg, 1.09 mmol) and the reaction mixture was allowed to stir at rt for 1 hr. During this time, the reaction became homogeneous. The MeOH and THF were removed in vacuo and the remaining aqueous mixture was acidified to pH ˜1 with 1N HCl. The mixture was then extracted with EtOAc (30 mL). The organic layer was washed with brine (20 mL), dried (MgSO4) and concentrated to afford 4,5-diphenylisoxazole-3-carboxylic acid (290 mg, 1.09 mmol, 100% yield) as a yellow solid. HPLC retention time=1.72 minutes (YMC Combi 4.6×30 mm S-5 ODS column) eluting with 10-90% aqueous methanol+0.1 TFA a 2 minute gradient.

Workup

  1. customThe MeOH and THF were removed in vacuo
  2. extractionThe mixture was then extracted with EtOAc (30 mL)
  3. washThe organic layer was washed with brine (20 mL)
  4. dry with materialdried (MgSO4)
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-6f728a1227054a118a7362536645a47c
Source dataset
uspto-grants-2013_01
Patent number
US08354398B2

Reaction notes

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