2-Amino-3-Hydroxypyridine → Oxazolo(4,5-b)pyridin-2(3H)-one

HRID 1091010Notes

Reaction equation

HRID 1091010 reaction equation
[NH2:1][C:2]1[C:7]([OH:8])=[CH:6][CH:5]=[CH:4][N:3]=1.[C:9](N1C=CN=C1)(N1C=CN=C1)=[O:10]>O1CCCC1>[O:8]1[C:7]2[C:2](=[N:3][CH:4]=[CH:5][CH:6]=2)[NH:1][C:9]1=[O:10]

Participants

4

Reactant 2

HCID 281142-Amino-3-HydroxypyridineHCID 682631,1'-Carbonyldiimidazole

Product 1

HCID 2799900Oxazolo(4,5-b)pyridin-2(3H)-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

5.5 g (0.05 mol) of 2-amino-3-hydroxypyridine are introduced into a three-necked flask and the system is placed under argon. 100 ml of anhydrous tetrahydrofuran (THF) are added. 12.15 g (0.075 mol) of 1,1'-carbonyl-diimidazole are then introduced. The mixture is heated to reflux for 5 hours (under argon). The THF is then evaporated off. The residue is taken up with dichloromethane. Washings of the organic phase are performed with NaOH (5%) solution (6×150 ml); the cyclized product passes into the aqueous phase and precipitates at a pH in the region of 5 (by adding 2 N hydrochloric acid solution). The product is filtered off and stored in a desiccator.

Workup

  1. temperatureThe mixture is heated
  2. temperatureto reflux for 5 hours (under argon)
  3. customThe THF is then evaporated off
  4. customprecipitates at a pH in the region of 5 (by adding 2 N hydrochloric acid solution)
  5. filtrationThe product is filtered off
  6. customstored in a desiccator

Sources & evidence

ORD record
ord-805db3772b0d481489032f117f3d3d45
Source dataset
uspto-grants-1992_01
Patent number
US05084456

Reaction notes

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