2-Amino-3-methoxymethoxypyridine → 8-Hydroxy-2-methyl-3-(2-propynyl)imidazo[1,2-a]pyridine

HRID 2231199Notes

Reaction equation

HRID 2231199 reaction equation
[NH2:1][C:2]1[C:7]([O:8]COC)=[CH:6][CH:5]=[CH:4][N:3]=1.S(O[CH:17]([CH2:21][C:22]#[CH:23])[C:18](=O)[CH3:19])(C)(=O)=O>C(O)C>[OH:8][C:7]1[C:2]2[N:3]([C:17]([CH2:21][C:22]#[CH:23])=[C:18]([CH3:19])[N:1]=2)[CH:4]=[CH:5][CH:6]=1

Participants

4

Reactant 2

HCID 143683452-Amino-3-methoxymethoxypyridineHCID 143683463-Mesyloxy-5-hexyn-2-one

Product 1

HCID 143683478-Hydroxy-2-methyl-3-(2-propynyl)imidazo[1,2-a]pyridineYield 21.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 2-amino-3-methoxymethoxypyridine (7.5 g) and 3-mesyloxy-5-hexyn-2-one (10.18 g), in ethanol (150 ml) was refluxed for 46.5 hours and then evaporated in vacuo. To the residue was added 20% sulfuric acid (75 ml) and the mixture was stirred for 5 hours at room temperature. The mixture was made alkaline with sodium bicarbonate and extracted with chloroform. The extract was washed with brine, dried over magnesium sulfate, and evaporated in vacuo. The residue was purified by column chromatography on silica gel (30 g) with chloroform and then a mixture of chloroform and methanol (30:1 to 20:1) as eluents. The eluates were evaporated in vacuo and the residue was recrystallized from a mixture of ethyl acetate and n-hexane to give 8-hydroxy-2-methyl-3-(2-propynyl)imidazo[1,2-a]pyridine (1.93 g).

Workup

  1. customevaporated in vacuo
  2. additionTo the residue was added 20% sulfuric acid (75 ml)
  3. extractionextracted with chloroform
  4. washThe extract was washed with brine
  5. dry with materialdried over magnesium sulfate
  6. customevaporated in vacuo
  7. customThe residue was purified by column chromatography on silica gel (30 g) with chloroform
  8. additiona mixture of chloroform and methanol (30:1 to 20:1) as eluents
  9. customThe eluates were evaporated in vacuo
  10. customthe residue was recrystallized from a mixture of ethyl acetate and n-hexane

Sources & evidence

ORD record
ord-af26c79837a94339b54a759b2a0c90a3
Source dataset
uspto-grants-1988_11
Patent number
US04782055

Reaction notes

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