Hydrochloric Acid → 4-Formyl-3-methylisoxazole-5-carboxylic acid

HRID 1090024Notes

Reaction equation

HRID 1090024 reaction equation
C([Li])CCC.[C:6]([NH2:10])([CH3:9])([CH3:8])[CH3:7].[CH3:11][C:12]1[CH:16]=[C:15]([C:17]([OH:19])=[O:18])[O:14][N:13]=1.Cl.[O:21]1CCC[CH2:22]1>O.CN(C)C=O>[C:6]([NH-:10])([CH3:9])([CH3:8])[CH3:7].[CH:22]([C:16]1[C:12]([CH3:11])=[N:13][O:14][C:15]=1[C:17]([OH:19])=[O:18])=[O:21]

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 6385Tert-ButylamineHCID 8028TetrahydrofuranHCID 8530853-Methylisoxazole-5-carboxylic acidHCID 178418339Butyllithium

Product 2

HCID 197652694-Formyl-3-methylisoxazole-5-carboxylic acidHCID 20624633t-Butylamide

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

56 ml of butyllithium (1.6 molar solution in n-hexane) are added dropwise, at -78° C., to 8 g of the tert-butylamine of 3-methylisoxazole-5-carboxylic acid in 150 ml of tetrahydrofuran. The mixture is stirred for 1 hour, after which 22 ml of dimethylformamide are slowly added dropwise. The mixture is allowed to reach room temperature overnight and is hydrolyzed with water, neutralized with concentrated hydrochloric acid and extracted with ether. The oil which remains after evaporation is chromatographed over silica gel using cyclohexane/ethyl acetate. The tert-butylamide of 4-formyl-3-methylisoxazole-5-carboxylic acid is obtained as the first fraction, in the form of pale yellow crystals of melting point 36°-38° C. (compound No. 2).

Workup

  1. waitto reach room temperature overnight
  2. extractionextracted with ether
  3. customafter evaporation
  4. customis chromatographed over silica gel

Sources & evidence

ORD record
ord-e5bc8ce29f6046c2a3b36fa8d090b4b6
Source dataset
uspto-grants-1992_01
Patent number
US05080708

Reaction notes

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