2-Thiophenecarboxaldehyde → 5-(Thiophen-2-yl)-1,3-oxazole

HRID 1455575Notes

Reaction equation

HRID 1455575 reaction equation
C1(C)C=CC(S([CH2:10][N+:11]#[C-:12])(=O)=O)=CC=1.[S:14]1[CH:18]=[CH:17][CH:16]=[C:15]1[CH:19]=[O:20].C(=O)([O-])[O-].[K+].[K+]>CO>[S:14]1[CH:18]=[CH:17][CH:16]=[C:15]1[C:19]1[O:20][CH:12]=[N:11][CH:10]=1

Participants

5

Reactant 3

HCID 73642-ThiophenecarboxaldehydeHCID 11430Potassium CarbonateHCID 161915Tosylmethyl isocyanide

Product 1

HCID 27972085-(Thiophen-2-yl)-1,3-oxazoleYield 37%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of p-toluenesulfonylmethyl isocyanide (3.0 g, 15.36 mmol) and Thiophene-2-carboxaldehyde (1.72 g, 15.36 mmol) in methanol (45 mL) under N2 is added potassium carbonate (2.12 g, 15.36 mmol). The mixture is heated to reflux for 5 hr, then cooled and concentrated in vacuum (cold water bath). The residue is partitioned between ether (100 mL) and water (100 mL). The organic layer is washed with water (100 mL), dried over magnesium sulfate and then concentrated in vacuum. The residue is purified over 35 g silica gel, eluted with ethyl acetate: heptane (1:5) to afford 5-thiophen-2-yl-oxazole (0.852 g, 37%).

Workup

  1. temperatureThe mixture is heated
  2. temperatureto reflux for 5 hr
  3. temperaturecooled
  4. concentrationconcentrated in vacuum (cold water bath)
  5. customThe residue is partitioned between ether (100 mL) and water (100 mL)
  6. washThe organic layer is washed with water (100 mL)
  7. dry with materialdried over magnesium sulfate
  8. concentrationconcentrated in vacuum
  9. customThe residue is purified over 35 g silica gel
  10. washeluted with ethyl acetate: heptane (1:5)

Sources & evidence

ORD record
ord-4a6cd616b2904089b454687aae5551de
Source dataset
uspto-grants-2009_01
Patent number
US07482448B2

Reaction notes

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