N-Phthaloylglycine → 2-[(3-Ethyl-1,2,4-oxadiazol-5-yl)methyl]-1H-isoindole-1,3(2H)-dione

Participants

Reaction Steps

A suspension of 26.0 g of carbonyldimidazole in 250 ml of THF is added to a solution of 65.7 g of phthalimidoacetic acid in 500 ml of tetrahydrofuran (THF) (abs.) at 40° C. After about 1 hour, no generation of gas can be detected any longer. A solution of 28.2 propioamidoxime in 50 ml of THF is now added and stirred for 24 hours at room temperature. After filtering off of the precipitate the filtrate is concentrated in a vacuum and refluxed on a water separator for 6 hours after addition of 500 ml of dry xylene. The still hot solution is separated from the oily residue and concentrated in a vacuum. After crystallization from ethanol, 31.5 g of phthalimide with a melting point of 106-107° C. (76.5% relative to carbonyldiimidazole) is obtained.

Provenance & Evidence