Isatin → 1-(2-cyclopropylethyl)-1H-indole-2,3-dione

Participants

Reaction Steps

To a suspension of sodium hydride (1.61 g, 41.9 mmol, 60% dispersion in mineral oil) in anhydrous N,N-dimethylformamide (25.0 mL) was added isatin (6.17 g, 41.9 mmol) at 0° C. The reaction mixture was stirred for 0.5 h followed by the addition of (2-bromoethyl)cyclopropane (Maercker, A., et al, Justus Liebigs Ann. Chem. (1972), 759:132-157) (9.25 g, 61.2 mmol). The resulting mixture was stirred at ambient temperature for 16 h and quenched with water (50.0 mL). The mixture was extracted with ethyl acetate (3×100 mL). The combined organic layers was washed with water (3×50.0 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness to yield the title compound (6.50 g, 90%) as a viscous gum: 1H NMR (300 MHz, CDCl3) δ 7.57-7.51 (m, 2H), 7.05 (t, 1H), 6.88 (d, 1H), 3.79-3.74 (m, 2H), 1.59-1.52 (m, 2H), 0.70-0.61 (m, 1H), 0.44-0.38 (m, 2H), 0.05-0.02 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 183.7, 158.2, 151.2, 138.4, 125.4, 123.6, 117.5, 110.3, 40.3, 32.2, 8.6, 4.3.

Provenance & Evidence