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

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence