Piperidine → 6-ethynyl-N-phenylimidazo[1,2-a]pyridine-2-carboxamide

HRID 1952208Notes

Reaction equation

HRID 1952208 reaction equation
I[C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH:8]=[C:9]([C:11]([NH:13][C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)=[O:12])[N:10]=2)[CH:7]=1.C[Si]([C:24]#[CH:25])(C)C.N1CCCCC1>Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[Cl-].[NH4+]>[C:24]([C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH:8]=[C:9]([C:11]([NH:13][C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)=[O:12])[N:10]=2)[CH:7]=1)#[CH:25]

Participants

6

Reactant 3

HCID 8082PiperidineHCID 66111TrimethylsilylacetyleneHCID 441359396-iodo-N-phenylimidazo[1,2-a]pyridine-2-carboxamide

Product 1

HCID 247716676-ethynyl-N-phenylimidazo[1,2-a]pyridine-2-carboxamide

Reagents, catalysts & solvents 2

HCID 178418476HCID 178418476, compoundCatalystHCID 25517Ammonium ChlorideSolvent

Conditions

Temperature
25 °C

Procedure

0.2 g of 6-iodo-N-phenylimidazo[1,2-a]pyridine-2-carboxamide, 156 μl of trimethylsilylacetylene, 20 mg of dichlorobis(triphenylphosphine)palladium and 2 ml of piperidine are charged to a 20 ml microwave tube. The mixture is heated for 15 minutes in the microwave device adjusted to 130° C. After cooling, the mixture is poured into 50 ml of a saturated aqueous ammonium chloride solution. Extraction is carried out twice with 70 ml of ethyl ether. The combined organic phases are separated by settling, dried and concentrated to dryness under reduced pressure. The residue is taken up in 4 ml of a 1M solution of tetrabutylammonium fluoride in THF and stirred at 25° C. for 16 hours. After evaporating the reaction medium to dryness, the residue is chromatographed on silica, elution being carried out with a mixture of cyclohexane and ethyl acetate (gradient from 0 to 35%), to give 30 mg of 6-ethynyl-N-phenylimidazo[1,2-a]pyridine-2-carboxamide in the form of a beige solid.

Workup

  1. temperatureThe mixture is heated for 15 minutes in the microwave device
  2. customadjusted to 130° C
  3. temperatureAfter cooling
  4. extractionExtraction
  5. customThe combined organic phases are separated
  6. customdried
  7. concentrationconcentrated to dryness under reduced pressure
  8. customAfter evaporating the reaction medium to dryness
  9. customthe residue is chromatographed on silica, elution
  10. additionbeing carried out with a mixture of cyclohexane and ethyl acetate (gradient from 0 to 35%)

Sources & evidence

ORD record
ord-e255c50541eb47bfba5bfa8999d86111
Source dataset
uspto-grants-2013_03
Patent number
US08404848B2

Reaction notes

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