1,1'-Carbonyldiimidazole → ethyl 5-hydroxy-1,2,4-oxadiazole-3-carboxylate

HRID 70896Notes

Reaction equation

HRID 70896 reaction equation
[OH:1][NH:2][C:3](=[NH:9])[C:4]([O:6][CH2:7][CH3:8])=[O:5].C1N=CN([C:15](N2C=NC=C2)=[O:16])C=1.C1CCN2C(=NCCC2)CC1>O1CCOCC1>[O:16]=[C:15]1[O:1][N:2]=[C:3]([C:4]([O:6][CH2:7][CH3:8])=[O:5])[NH:9]1

Participants

5

Reactant 3

HCID 682631,1'-CarbonyldiimidazoleHCID 811841,8-Diazabicyclo(5.4.0)undec-7-eneHCID 178472862HCID 178472862, compound

Product 1

HCID 135973140ethyl 5-hydroxy-1,2,4-oxadiazole-3-carboxylateYield 100.3%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Conditions

Temperature
80 °C

Procedure

To a solution of ethyl 2-(hydroxyamino)-2-iminoacetate (2 g, 15.14 mmol) in dioxane (15.00 mL) is added CDI (2.7 g, 16.65 mmol) and DBU (2.5 ml, 16.65 mmol) at room temperature. After stirring for 1 hour at 80° C., the reaction is quenched with 1N HCl, and the crude is diluted with EtOAc. The organic layer is washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure to give ethyl 5-oxo-4,5-dihydro-1,2,4-oxadiazole-3-carboxylate (2.4 g). HPLC retention time=0.72 minutes (condition D); MS 159.1 (M+1).

Workup

  1. customthe reaction is quenched with 1N HCl
  2. additionthe crude is diluted with EtOAc
  3. washThe organic layer is washed with brine
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-19daf404387445e0bc0f718819b306ac
Source dataset
uspto-grants-2014_09
Patent number
US08822534B2

Reaction notes

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