Chloroacetaldehyde → Imidazo[1,2-a]pyridin-8-ylmethanol

HRID 1789196Notes

Reaction equation

HRID 1789196 reaction equation
[OH:1][CH2:2][C:3]1[C:4]([NH2:9])=[N:5][CH:6]=[CH:7][CH:8]=1.Cl[CH2:11][CH:12]=O.C(=O)(O)[O-].[Na+]>C(O)C>[OH:1][CH2:2][C:3]1[C:4]2[N:5]([CH:11]=[CH:12][N:9]=2)[CH:6]=[CH:7][CH:8]=1

Participants

5

Reactant 3

HCID 33ChloroacetaldehydeHCID 516892Sodium BicarbonateHCID 11159325(2-Aminopyridin-3-yl)methanol

Product 1

HCID 11029987Imidazo[1,2-a]pyridin-8-ylmethanolYield 129.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 2.92 g (23 mmole) of 3-hydroxymethyl-2-pyridinamine, 6.15 g (35 mmole) of chloroacetaldehyde, and 2.0 g (35 mmole) of sodium bicarbonate in 100 ml of ethanol was heated at reflux for 1.5 hours. The mixture was filtered and the filtrate was concentrated in vacuo to a solid. Recrystallization from diethyl ether yielded 4.4 g of 8-hydroxymethylimidazo[1,2-a]pyridine, as confirmed by the nmr and infrared spectra. A mixture of 683 mg (3.8 mmole) of 2-mercapto-5-methoxybenzimidazole and 700 mg (3.8 mmole) of 8-hydroxymethylimidazo[1,2-a]pyridine was dissolved in 3 ml of 30% hydrogen bromide in acetic acid and heated on a steam bath. After being cooled to room temperature, the mixture was partitioned between 5% aqueous sodium hydroxide and dichloromethane. The organic layer was dried over sodium sulfate, filtered, and concentrated to yield the title compound as an oil. Structure assignment was supported by the nmr and infrared spectra.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 1.5 hours
  3. filtrationThe mixture was filtered
  4. concentrationthe filtrate was concentrated in vacuo to a solid
  5. customRecrystallization from diethyl ether

Sources & evidence

ORD record
ord-4380a12b563c4abdbd36dc933a51f2b0
Source dataset
uspto-grants-1987_08
Patent number
US04687775

Reaction notes

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