2-Amino-3-benzyloxypyridine → 8-Benzyloxy-3-(2-propynyl)-2-methylimidazo[1,2-a]pyridine

HRID 4300

Reaction equation

HRID 4300 reaction equation
[NH2:1][C:2]1[C:7]([O:8][CH2:9][C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)=[CH:6][CH:5]=[CH:4][N:3]=1.S(OC(CC#C)C(=O)C)([C:19]1[CH:25]=[CH:24][C:22](C)=[CH:21][CH:20]=1)(=O)=O>C(O)C>[CH2:9]([O:8][C:7]1[C:2]2[N:3]([C:19]([CH2:20][C:21]#[CH:22])=[C:25]([CH3:24])[N:1]=2)[CH:4]=[CH:5][CH:6]=1)[C:10]1[CH:11]=[CH:12][CH:13]=[CH:14][CH:15]=1

Participants

4

Reactant 2

HCID 903342-Amino-3-benzyloxypyridineHCID 138258933-Tosyloxy-5-hexyn-2-one

Product 1

HCID 138258978-Benzyloxy-3-(2-propynyl)-2-methylimidazo[1,2-a]pyridineYield 31%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 2-amino-3-benzyloxypyridine (2 g) and 3-tosyloxy-5-hexyn-2-one (2.66 g) in ethanol (15 ml) was stirred and refluxed for 24 hours and then evaporated in vacuo. To the residue was added an aqueous solution of sodium bicarbonate and the mixture was extracted with ethyl acetate. The extract was washed with water, dried over magnesium sulfate and evaporated in vacuo. The oily residue was purified by column chromatography on silica gel (50 g) using chloroform as an eluent to give a solid, which was recrystallized from a mixture of methylene chloride and diethyl ether to give 8-benzyloxy-3-(2-propynyl)-2-methylimidazo[1,2-a]pyridine (0.855 g).

Workup

  1. temperaturerefluxed for 24 hours
  2. customevaporated in vacuo
  3. additionTo the residue was added an aqueous solution of sodium bicarbonate
  4. extractionthe mixture was extracted with ethyl acetate
  5. washThe extract was washed with water
  6. dry with materialdried over magnesium sulfate
  7. customevaporated in vacuo
  8. customThe oily residue was purified by column chromatography on silica gel (50 g)
  9. customto give a solid, which
  10. customwas recrystallized from a mixture of methylene chloride and diethyl ether

Sources & evidence

ORD record
ord-30e0a8c847e3408db73ba26ed7bed814
Source dataset
uspto-grants-1988_02
Patent number
US04725601

Linked notes

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