193269-82-8

21715-90-2

4457-32-3

193269-82-8

GENERAL STEPS: To a stirred solution of tetrahydrofuran (THF, 500 mL) of 4-nitrobenzyl chloroformate (27.40 g) was added N-hydroxy-5-norbornene-2,3-dicarboximide (22.76 g) at 0 °C, followed by the slow dropwise addition of a THF (200 mL) solution of triethylamine (Et3N, 17.72 mL). The reaction mixture was gradually warmed to room temperature with stirring and the reaction was continued overnight. Subsequently, the reaction vessel was placed in a refrigerator at -5 °C for 1 h to promote precipitation of triethylamine hydrochloride, and the precipitate was removed by filtration. The filtrate was concentrated to dryness and the obtained residue was stirred vigorously in methanol (MeOH, 400 mL) for 1 hour, after which it was filtered to obtain the target product (N-hydroxy-5-norbornene-2,3-dicarboxyimido)-4-nitrobenzoate as a white solid (42.03 g, yield: 92%).