Hexanoic Acid → N-Hydroxysuccinimide caproic acid ester

Participants

Reaction Steps

To a solution of 55.2 g (0.475 mol) of hexanoic acid and 60.161 g (0.523 mol) of N-hydroxy succinimide in 600 mL THF, 107.855 g (0.523 mol) of DCCI was added. The mixture was cooled with an ice-water bath and stirred for 5 h. The dicyclohexyl urea (DCU) precipitate was removed by filtration, and the THF solvent was removed by vacuum rotary evaporation. The yellow oil residue was dissolved again in 600 mL hexane followed by another vacuum filtration to remove the excess dicyclohexyl urea (DCU). The filtrate was then concentrated under vacuum evaporation yield a white solid, which was vacuum dried at ambient temperature to give 88.187 g (87.07%) of N-hexanoyloxy succinimide. IR (KBr): 1816 cm−1 (ν(C═O) of ester), 1745-1786 cm−1 (ν(C═O) of imide). 1H-NMR (DMSO-d6, ppm): 0.86 (3H, —CH3), 1.31 (4H, —(CH2)2CH3), 1.62 (2H, CH2CH2COO—), 2.64 (2H, —CH2COO—), 2.80 (4H, —COCH2CH2CO—).

Provenance & Evidence