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

HRID 356272Notes

Reaction equation

HRID 356272 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.CO>O1CCCC1.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 3

HCID 887MethanolHCID 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 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

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-de63d304517348a0ab7c40e02978e549
Source dataset
uspto-grants-1998_11
Patent number
US05834501

Reaction notes

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