Potassium Carbonate → 6-(oxazol-5-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide

HRID 1878454Notes

Reaction equation

HRID 1878454 reaction equation
[CH:1]([C:3]1[CH:4]=[CH:5][C:6]2[N:7]([CH:9]=[C:10]([C:12]([NH:14][C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=3)=[O:13])[N:11]=2)[CH:8]=1)=[O:2].C(=O)([O-])[O-].[K+].[K+].C1(C)C=CC(S([CH2:36][N+:37]#[C-:38])(=O)=O)=CC=1>CO>[O:2]1[C:1]([C:3]2[CH:4]=[CH:5][C:6]3[N:7]([CH:9]=[C:10]([C:12]([NH:14][C:15]4[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=4)=[O:13])[N:11]=3)[CH:8]=2)=[CH:38][N:37]=[CH:36]1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 161915Tosylmethyl isocyanideHCID 247716156-formyl-N-phenylimidazo[1,2-a]pyridine-2-carboxamide2×

Product 1

HCID 441377676-(oxazol-5-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamideYield 34.9%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a suspension of 200 mg of 6-formyl-N-phenylimidazo[1,2-a]pyridine-2-carboxamide (Intermediate 8) in 10 mL of methanol are added 104 mg of potassium carbonate and 147 mg of para-toluenesulfonylmethylisonitrile (TOSMIC). The reaction mixture is refluxed for 2 hours and then evaporated to dryness under reduced pressure, taken up in 300 mL of dichloromethane and washed with water. The organic phase is dried and concentrated to dryness on silica and then chromatographed on a silica cartridge, eluting with a gradient of from 0 to 20% of methanol in dichloromethane. The fractions containing the expected product are concentrated to dryness and the solid obtained is triturated with a small amount of dichloromethane, filtered off and dried to give 80 mg of 6-(oxazol-5-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide in the form of a white solid.

Workup

  1. temperatureThe reaction mixture is refluxed for 2 hours
  2. customevaporated to dryness under reduced pressure
  3. washwashed with water
  4. customThe organic phase is dried
  5. concentrationconcentrated to dryness on silica
  6. customchromatographed on a silica cartridge
  7. washeluting with a gradient of from 0 to 20% of methanol in dichloromethane
  8. additionThe fractions containing the expected product
  9. concentrationare concentrated to dryness
  10. customthe solid obtained
  11. customis triturated with a small amount of dichloromethane
  12. filtrationfiltered off
  13. customdried

Sources & evidence

ORD record
ord-1eb4f777fc8441b89b3f037614ce0b07
Source dataset
uspto-grants-2012_11
Patent number
US08314109B2

Reaction notes

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