Potassium Carbonate → 4-Ethyl-5-[4-(trifluoromethyl)phenyl]oxazole

HRID 1672572Notes

Reaction equation

HRID 1672572 reaction equation
[F:1][C:2]([F:12])([F:11])[C:3]1[CH:10]=[CH:9][C:6]([CH:7]=[O:8])=[CH:5][CH:4]=1.[N+:13]([CH:15](S(C1C=CC(C)=CC=1)(=O)=O)[CH2:16][CH3:17])#[C-:14].C([O-])([O-])=O.[K+].[K+]>CO>[CH2:16]([C:15]1[N:13]=[CH:14][O:8][C:7]=1[C:6]1[CH:9]=[CH:10][C:3]([C:2]([F:11])([F:12])[F:1])=[CH:4][CH:5]=1)[CH3:17]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 679964-(Trifluoromethyl)benzaldehydeHCID 204671891-Ethyl-1-tosylmethyl isocyanide

Product 1

HCID 666965954-Ethyl-5-[4-(trifluoromethyl)phenyl]oxazoleYield 88.3%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 4-(trifluoromethyl)benzaldehyde (3.60 mL, 27.0 mmol), 1-(1-isocyanopropylsulfonyl)-4-methylbenzene (6.02 g, 27.0 mmol), and K2CO3 (4.47 g, 32.4 mmol) in MeOH (100 mL) was heated to reflux. After 1.5 hr the reaction mixture was cooled to ambient temperature, and the volatiles evaporated at reduced pressure. The residue was partitioned between Et2O (100 mL) and H2O (100 mL). The separated aqueous phase was extracted with Et2O. The combined organic extract was washed with brine, dried (MgSO4), filtered, and concentrated in vacuo. Chromatography on silica gel (Analogix® Intelliflash 280™; SF40-150 g column; 10% to 30% EtOAc/hexanes eluant, 30 min) afforded 5.75 g (88%) of the title compound as a pale yellow oil. 1H NMR (300 MHz, DMSO-d6) δ 8.44 (s, 1H), 7.90-7.78 (m, 4H), 2.79 (q, J=7.5, 2H), 1.23 (t, J=7.5, 3H). MS (DCI+) m/z 242 (M+H).

Workup

  1. temperaturewas heated to reflux
  2. customthe volatiles evaporated at reduced pressure
  3. customThe residue was partitioned between Et2O (100 mL) and H2O (100 mL)
  4. extractionThe separated aqueous phase was extracted with Et2O
  5. extractionThe combined organic extract
  6. washwas washed with brine
  7. dry with materialdried (MgSO4)
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d05a13115b46489fa8f87cfcdcb3824e
Source dataset
uspto-grants-2011_08
Patent number
US07998993B2

Reaction notes

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