N-3-Bromopropylphthalimide → Dibenzyl-2-(3-phthalimidopropyl)malonate

Participants

Reaction Steps

A solution of dibenzyl malonate (20 g) in anhydrous THF (200 ml) was treated at 0° C. with sodium hydride (60% dispersion in mineral oil, 3.1 g). The mixture was allowed to warm to room temperature and stirred for 30 minutes under nitrogen. The mixture was then treated with a solution of N-(3-bromopropyl)phthalimide (20.5 g) in THF (100 ml) and heated at reflux for 12 hours. The reaction was then cooled, filtered, and the filtrate evaporated in vacuo. The residue was partitioned between ethyl acetate (200 ml) and saturated aqueous ammonium chloride (150 ml). The organic layer was washed with water (100 ml), brine (100 ml), dried (MgSO4), filtered and the filtrate evaporated in vacuo. The residue was purified by column chromatography on silica gel eluting with 20% ethyl acetate in hexane to yield the title compound (17.5 g, 50%) as a white solid.

Provenance & Evidence