Water → HCID 58017101, compound

Participants

Reaction Steps

A stirred suspension of sodium hydride (60% dispersion in oil, 7 mg, 0.16 mmol) in anhydrous tetrahydrofuran (2 ml) was treated with 1′-benzyl-5-chloro-1H-spiro[indole-3,3′-pyrrolidine]-2,2′,5′-trione, intermediate 14 (50 mg, 0.15 mmol). After stirring at ambient temperature for 30 minutes, tert-butyl acrylate (0.03 ml, 0.19 mmol) was added and the resultant mixture stirred for 2 hours and left to stand at ambient temperature for 18 hours. Water (15 ml) was added and the mixture extracted with ethyl acetate (3×15 ml). The combined extracts were washed with brine (15 ml), dried (MgSO4) and the solvent removed in vacuo to give the crude 3-(1′-Benzyl-5-chloro-2,2′,5′-trioxo-spiro[indole-3,3′-pyrrolidin]-1-yl)-propionic acid tert-butyl ester. This was purified by flash chromatography (silica) eluting with petroleum ether (40-60) containing an increasing amount (0 to 50%) of ethyl acetate to give a white solid (37 mg 54%). This was sufficiently pure by 1H NMR to take on to the final hydrolysis step.

Provenance & Evidence