Sodium hydride (0.16 g) was added to a solution of 3-[2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)ethyl]-1H-indole-5-carbonitrile (2.0 g) in dry dimethylformamide (40 ml) under nitrogen. After 0.5 hour. benzyl chloride was added and after a further 2 hours the mixture was diluted with water (150 ml) and extracted with ethyl acetate (3×40 ml). Evaporation of the washed (H2O) and dried (MgSO4) extract gave a red oil which was triturated with ether and then crystallised from ethanol to give the title compound as yellow microcrystals (1.2 g) m.p. 182°-4° C. T.L.C. Silica, ether Rf 0.45.
