Methanol → 5-(1H-indol-2-yl)-1,3-oxazole

HRID 1035805Notes

Reaction equation

HRID 1035805 reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[C:2]1[CH:10]=[O:11].CO.C1(C)C=CC(S([CH2:23][N+:24]#[C-:25])(=O)=O)=CC=1.C(=O)([O-])[O-].[K+].[K+]>CCCCCC>[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[C:2]1[C:10]1[O:11][CH:25]=[N:24][CH:23]=1

Participants

6

Reactant 4

HCID 887MethanolHCID 11430Potassium CarbonateHCID 96389Indole-2-carboxaldehydeHCID 161915Tosylmethyl isocyanide

Product 1

HCID 8520455-(1H-indol-2-yl)-1,3-oxazoleYield 79.8%

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

To a 100 mL round-bottom flask was added 1H-indole-2-carbaldehyde 18 (1.52 g, 10.48 mmol), methanol (50 mL), p-toluene sulfonylmethyl isocyanide (2.25 g, 11.52 mmol), followed by potassium carbonate (1.86 g, 13.45 mmol). The reaction mixture was stirred at reflux for about 1.5 hour and followed by TLC. The solvent was then evaporated and saturated aq.NaHCO3 was added. The resultant suspension was extracted with CH2Cl2 (3×30 mL). Combined organic layers were washed with brine, dried (anhydrous Na2SO4), and concentrated to leave a yellow solid. Crude product was further purified by silica-column chromatographed (Biotage) using Acetone:Hexane as an eluent to yield 5-(1H-indol-2-yl)oxazole 19 (1.54 g, 79% yield). MS (ES) m/z 185 (M+H+).

Workup

  1. temperatureat reflux for about 1.5 hour
  2. customThe solvent was then evaporated
  3. additionNaHCO3 was added
  4. extractionThe resultant suspension was extracted with CH2Cl2 (3×30 mL)
  5. washCombined organic layers were washed with brine
  6. dry with materialdried (anhydrous Na2SO4)
  7. concentrationconcentrated
  8. customto leave a yellow solid
  9. customCrude product was further purified by silica-column
  10. customchromatographed (Biotage)

Sources & evidence

ORD record
ord-8128ade1152742149cad27eb7c67a01f
Source dataset
uspto-grants-2013_10
Patent number
US08546400B2

Reaction notes

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