Methanol → Imidazo[1,2-a]pyridin-2-ylmethanol

HRID 55480Notes

Reaction equation

HRID 55480 reaction equation
[BH4-].[Li+].[N:3]1[C:4]([C:12](OCC)=[O:13])=[CH:5][N:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=12.O1CCCC1.CO>O>[N:3]1[C:4]([CH2:12][OH:13])=[CH:5][N:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=12

Participants

6

Reactant 4

HCID 887MethanolHCID 8028TetrahydrofuranHCID 818807Ethyl imidazo[1,2-a]pyridine-2-carboxylateHCID 4148881Lithium borohydride

Product 1

HCID 2795540Imidazo[1,2-a]pyridin-2-ylmethanolYield 7.8%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

3.68 g of lithium borohydride were added at room temperature to a solution of 9.17 g of ethyl imidazo[1,2-a]pyridine-2-carboxylate [described in J. Org. Chem., 30, 2403 -2407 (1965)]in 200 ml of tetrahydrofuran, and then 20 ml of methanol were added dropwise to the mixture, which was then allowed to stand overnight at room temperature. At the end of this time, the reaction mixture was diluted with 10 ml of water and then concentrated by evaporation under reduced pressure. The concentrate was mixed with an aqueous solution of sodium chloride, after which it was extracted with ethyl acetate. The extract was dried over anhydrous sodium sulfate, after which the solvent was removed by distillation under reduced pressure. The resulting residue was purified by column chromatography through silica gel, using a 5:1 by volume mixture of ethyl acetate and ethanol as the eluent. The product was then recrystallized from a mixture of ethyl acetate and hexane, to give 0.56 g of the title compound, melting at 126°-128° C.

Workup

  1. concentrationconcentrated by evaporation under reduced pressure
  2. additionThe concentrate was mixed with an aqueous solution of sodium chloride
  3. extractionafter which it was extracted with ethyl acetate
  4. dry with materialThe extract was dried over anhydrous sodium sulfate
  5. customafter which the solvent was removed by distillation under reduced pressure
  6. customThe resulting residue was purified by column chromatography through silica gel
  7. additionby volume mixture of ethyl acetate and ethanol as the eluent
  8. customThe product was then recrystallized from a mixture of ethyl acetate and hexane

Sources & evidence

ORD record
ord-0d2563a5481c494797041213f762def6
Source dataset
uspto-grants-1997_04
Patent number
US05624935

Reaction notes

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