Hydrochloric Acid → HCID 19973434, compound

HRID 1452042Notes

Reaction equation

HRID 1452042 reaction equation
[Mg].BrCC.Br[C:6]1[CH:7]=[CH:8][C:9]2[N:10]([CH:12]=[C:13]([CH3:15])[N:14]=2)[CH:11]=1.[CH2:16]=[O:17].Cl>O1CCCC1.II>[CH3:15][C:13]1[N:14]=[C:9]2[CH:8]=[CH:7][C:6]([CH2:16][OH:17])=[CH:11][N:10]2[CH:12]=1

Participants

8

Reactant 5

HCID 313Hydrochloric AcidHCID 712Formaldehyde2×HCID 6332Ethyl Bromide2×HCID 5462224MagnesiumHCID 124289606-Bromo-2-methylimidazo[1,2-a]pyridine

Product 1

HCID 19973434HCID 19973434, compoundYield 91.9%

Reagents, catalysts & solvents 2

HCID 807IodineCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

In a nitrogen atmosphere, 78.56 g of magnesium was added to 2 l of tetrahydrofuran and 0.3 g of iodine and 18 ml of bromoethane were added to the obtained mixture to prepare a Grignard reagent. A solution of 170.5 g of 6-bromo-2-methylimidazo[1,2-a]pyridine and 162 ml of bromoethane in 500 ml of tetrahydrofuran was slowly dropped into the above reaction mixture. After the completion of the dropping, the obtained mixture was heated under reflux for 30 minutes and then cooled with ice. Formaldehyde gas generated by heating a container containing 242 g of paraformaldehyde to 200° C. was introduced into the reaction mixture by the use of a nitrogen stream. After 30 minutes, dilute hydrochloric acid was added to the resulting mixture and the obtained mixture was filtered to remove insolubles. The filtrate was alkalinized with concentrated aqueous ammonia and extracted with chloroform. The organic phase was dried over anhydrous magnesium sulfate and distilled to remove the solvent. The residue was purified by silica gel column chromatography [solvent: dichloromethane/methanol (30:1 to 10:1)] to give 120 g of the title compound as a pale-yellow solid (yield: 91.9%).

Workup

  1. additionwere added to the obtained mixture
  2. temperatureAfter the completion of the dropping, the obtained mixture was heated
  3. temperatureunder reflux for 30 minutes
  4. temperaturecooled with ice
  5. temperatureby heating a container
  6. additionwas introduced into the reaction mixture by the use of a nitrogen stream
  7. filtrationthe obtained mixture was filtered
  8. customto remove insolubles
  9. extractionextracted with chloroform
  10. dry with materialThe organic phase was dried over anhydrous magnesium sulfate
  11. distillationdistilled
  12. customto remove the solvent
  13. customThe residue was purified by silica gel column chromatography [solvent: dichloromethane/methanol (30:1 to 10:1)]

Sources & evidence

ORD record
ord-29559e7c5f4c41a186cfca5243451495
Source dataset
uspto-grants-1997_02
Patent number
US05606061

Reaction notes

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