Toluene → HCID 44137632, compound

HRID 2363693Notes

Reaction equation

HRID 2363693 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].C1(C)C=CC(S(O)(=O)=[O:28])=CC=1.[C:32]1([CH3:38])C=CC=CC=1>CO.C(O)CO>[O:2]1[CH2:38][CH2:32][O:28][CH:1]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

Participants

6

Reactant 3

HCID 1140TolueneHCID 6101p-Toluenesulfonic acid2×HCID 247716156-formyl-N-phenylimidazo[1,2-a]pyridine-2-carboxamide2×

Product 1

HCID 44137632HCID 44137632, compound

Reagents, catalysts & solvents 2

HCID 174Ethylene GlycolSolvent2×HCID 887MethanolSolvent

Procedure

To a solution of 137 mg of 6-formyl-N-phenylimidazo[1,2-a]pyridine-2-carboxamide (Intermediate 8) in 5 mL of toluene are added 45 μL of ethylene glycol, 169 mg of para-toluenesulfonic acid and molecular sieves. The mixture is refluxed for 24 hours in a round-bottomed flask equipped with Dean-Stark apparatus, and then cooled, filtered, diluted with 100 mL of dichloromethane and washed with 2N sodium hydroxide and with water. The organic phases are dried and concentrated to dryness to give a mixture of the starting material and of the expected product, which is redissolved in 5 mL of methanol containing 410 μL of ethylene glycol, 130 mg of para-toluenesulfonic acid and molecular sieves. The mixture is heated for 16 hours at reflux and then cooled, filtered and concentrated to dryness. The residue is chromatographed on a silica cartridge, eluting with a 70/30 mixture of dichloromethane and ethyl acetate to give 53 mg of 6-(1,3-dioxolan-2-yl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide in the form of a white solid.

Workup

  1. temperatureThe mixture is refluxed for 24 hours in a round-bottomed flask
  2. customequipped with Dean-Stark apparatus
  3. temperaturecooled
  4. filtrationfiltered
  5. additiondiluted with 100 mL of dichloromethane
  6. washwashed with 2N sodium hydroxide and with water
  7. customThe organic phases are dried
  8. concentrationconcentrated to dryness
  9. customto give
  10. additiona mixture of the starting material

Sources & evidence

ORD record
ord-f6c63321491e41b1aa868e68cd68e150
Source dataset
uspto-grants-2014_04
Patent number
US08691990B2

Reaction notes

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