Benzaldehyde → 3-Butyl-5-([E]-styryl)-isoxazole-4-carboxylic acid

HRID 1514738Notes

Reaction equation

HRID 1514738 reaction equation
C([O:3][C:4]([C:6]1[C:7]([CH2:12][CH2:13][CH2:14][CH3:15])=[N:8][O:9][C:10]=1[CH3:11])=[O:5])C.[CH:16](=O)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.[O-]CC.[Na+].Cl>C(O)C>[CH2:12]([C:7]1[C:6]([C:4]([OH:3])=[O:5])=[C:10](/[CH:11]=[CH:16]/[C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[O:9][N:8]=1)[CH2:13][CH2:14][CH3:15]

Participants

6

Reactant 4

HCID 240BenzaldehydeHCID 313Hydrochloric AcidHCID 2723922Sodium ethoxideHCID 665992233-Butyl-5-methyl-isoxazole-4-carboxylic acid ethyl ester

Product 1

HCID 666437323-Butyl-5-([E]-styryl)-isoxazole-4-carboxylic acidYield 42%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of 3-butyl-5-methyl-isoxazole-4-carboxylic acid ethyl ester (15.0 g, 71.0 mmol) and benzaldehyde (7.2 mL, 71.0 mmol) in ethanol (100 mL) was added sodium ethoxide solution (21% in ethanol, 29.1 mL, 78.0 mmol) and the reaction mixture was stirred at reflux for 2 h, cooled to room temperature and stirred for 17 h. Hydrochloric acid (1 N, 85 mL) was added and the resulting mixture was extracted twice with dichloromethane. The combined phases were washed with brine, dried over sodium sulfate and filtered. The filtrate was concentrated to a bright yellow pasty solid and recrystallized from hot heptane/ethyl acetate to afford the title compound (8.0 g, 42%) as a yellow solid. MS: m/e=270.4 [M−H]−.

Workup

  1. temperatureat reflux for 2 h
  2. stirringstirred for 17 h
  3. extractionthe resulting mixture was extracted twice with dichloromethane
  4. washThe combined phases were washed with brine
  5. dry with materialdried over sodium sulfate
  6. filtrationfiltered
  7. concentrationThe filtrate was concentrated to a bright yellow pasty solid
  8. customrecrystallized from hot heptane/ethyl acetate

Sources & evidence

ORD record
ord-7fb008da5e8c47f58bf5792d2bdb3ef4
Source dataset
uspto-grants-2012_07
Patent number
US08222246B2

Reaction notes

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