Ethyl propiolate → 3-(3-Fluoro-4-nitro-phenyl)-isoxazole-5-carboxylic acid ethyl ester

HRID 75794Notes

Reaction equation

HRID 75794 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[N+:11]([O-:13])=[O:12])[CH:5]=[N:6][OH:7].OC1C(OS(C2C=CC(C)=CC=2)(=O)=O)=C(I)C=CC=1.[C:33]([O:37][CH2:38][CH3:39])(=[O:36])[C:34]#[CH:35]>C(#N)C.C(OCC)(=O)C>[CH2:38]([O:37][C:33]([C:34]1[O:7][N:6]=[C:5]([C:4]2[CH:8]=[CH:9][C:10]([N+:11]([O-:13])=[O:12])=[C:2]([F:1])[CH:3]=2)[CH:35]=1)=[O:36])[CH3:39]

Participants

6

Reactant 3

HCID 12182Ethyl propiolateHCID 21918218Hydroxy tosyloxy iodobenzeneHCID 762213223-Fluoro-4-nitro-benzaldehyde oxime

Product 1

HCID 673525333-(3-Fluoro-4-nitro-phenyl)-isoxazole-5-carboxylic acid ethyl esterYield 74%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of 3-fluoro-4-nitro-benzaldehyde oxime (6 g; 32.6 mmol) in acetonitrile (120 mL) was added hydroxy tosyloxy iodobenzene (16.58 g; 42.3 mmol) and ethyl propiolate (6.38 g; 65.2 mmol) under stirring. The resulting reaction mixture was stirred at 80° C. for 2-3 h. After the completion of the reaction, it was evaporated to dryness. The solid thus obtained was dissolved in ethyl acetate and washed with brine and dried over anhydrous Na2SO4. The solvent was removed and the residue was purified by flash chromatography over silica gel with 20% ethyl acetate in light petroleum to give 6.4 g (74%) of the title compound. IR (KBr): 3134, 3060, 2975, 1717, 1610, 1593, 1522, 1458, 1446 cm−1; MS (m/z): 279 (M−−1); 1H NMR (DMSO-d6) δ: 1.31-136 (t, 3H, CH2CH3), 4.36-4.43 (q, 2H, CH2CH3), 8.04 (d, 1H, J=9.0, 6′-H), 8.09 (s, 1H, 4-H), 8.16 (d, 1H), 8.30 (t, 1H).

Workup

  1. customThe resulting reaction mixture
  2. stirringwas stirred at 80° C. for 2-3 h
  3. customAfter the completion of the reaction, it
  4. customwas evaporated to dryness
  5. customThe solid thus obtained
  6. washwashed with brine
  7. dry with materialdried over anhydrous Na2SO4
  8. customThe solvent was removed
  9. customthe residue was purified by flash chromatography over silica gel with 20% ethyl acetate in light petroleum

Sources & evidence

ORD record
ord-52ccde5894e24701be610c2bcb6eea7f
Source dataset
uspto-grants-2014_09
Patent number
US08835428B2

Reaction notes

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