Sodium hydride → Ethyl 3-(cyclopropylidenemethyl)-1-[3-(trifluoromethyl)benzyl]-1H-indole-2-carboxylate

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Reaction Conditions

Reaction Steps

Sodium hydride (60% dispersion in mineral oil, 128 mg, 3.20 mmol) was suspended in anhydrous tetrahydrofuran (10 mL) and cooled to 0° C. Triphenyl-cyclopropylphosphonium bromide (1.23 g, 3.20 mmol) was added as a solid all at once, and the mixture was allowed to stir at room temperature. Once gas evolution ceased, a tetrahydrofuran solution of ethyl 3-formyl-1-[3-(trifluoromethyl)benzyl]-1H-indole-2-carboxylate (Example 40, 1.0 g, 2.7 mmol) was added, the mixture was stirred for 15 hours, and the resulting mixture was partitioned between water and ethyl acetate. Layers were separated, and the aqueous layer was extracted with ethyl acetate (2×). The combined organic layers were dried over anhydrous magnesium sulfate and concentrated. The resulting crude oil was purified by flash chromatography on silica gel eluted with 5% ethyl acetate/hexane. The title compound was collected as a bright yellow oil (403 mg, 38%). The product had: 1H NMR (300 MHz, CDCl3) δ 8.04 (d, 1 H), 7.53 (s, 1 H), 7.41-7.38 (m, 2 H), 7.29-7.20 (m, 3 H), 7.15-7.12 (m, 1 H), 7.05 (d, 1 H), 5.72 (s, 2 H), 4.27 (q, 2 H), 1.50-1.45 (m, 2 H), 1.25 (t, 3 H), 0.83-0.76 (m, 2 H); mass spectroscopy gave MH+=400.2 (calc'd exact mass for C23H20F3NO2=399.14).

Provenance & Evidence