Lithium hydroxide, monohydrate → 5-Ethyl-3-phenyl-1,2-oxazole-4-carboxylic acid

HRID 494318Notes

Reaction equation

HRID 494318 reaction equation
C[O:2][C:3]([C:5]1[C:6]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[N:7][O:8][C:9]=1[CH2:10][CH3:11])=[O:4].O[Li].O>C1COCC1.O>[CH2:10]([C:9]1[O:8][N:7]=[C:6]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[C:5]=1[C:3]([OH:4])=[O:2])[CH3:11]

Participants

5

Reactant 2

HCID 168937Lithium hydroxide, monohydrateHCID 57466732HCID 57466732, compound

Product 1

HCID 135451045-Ethyl-3-phenyl-1,2-oxazole-4-carboxylic acidYield 85.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

8.0 g (34 mmol) of 5-Ethyl-3-phenyl-isoxazole-4-carboxylic acid methyl ester (prepared according to: Synthesis 2003; 1347-1356) was dissolved in 50 mL of THF, to which 7.2 g (170 mmol) LiOH.H2O in 25 ml of H2O was added in one portion. The reaction mixture was refluxed for 12 h. After evaporation of THF, the aqueous solution was acidified with 2N HCl to pH=2. After extraction with ethyl acetate (3×100 mL), the combined organic extracts were dried over Na2SO4 and evaporated to dryness to give 5-Ethyl-3-phenyl-isoxazole-4-carboxylic acid (6.32 g) in 72.3% yield as a red solid. (m/e): 216.2 (M−; 100%).

Workup

  1. additionwas added in one portion
  2. temperatureThe reaction mixture was refluxed for 12 h
  3. customAfter evaporation of THF
  4. extractionAfter extraction with ethyl acetate (3×100 mL)
  5. dry with materialthe combined organic extracts were dried over Na2SO4
  6. customevaporated to dryness

Sources & evidence

ORD record
ord-8f690ec956e746a5bebd3b96e36b7960
Source dataset
uspto-grants-2009_05
Patent number
US07538132B2

Reaction notes

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