Phthalic Anhydride → 2-(1H-pyrrolo[2,3-b]pyridin-6-yl)-isoindole-1,3-dione

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Reaction Conditions

Reaction Steps

1H-Pyrrolo[2,3-b]pyridin-6-ylamine (0.12 g, 0.9 mmol) was suspended in acetic acid (1.5 mL), then phthalic anhydride (133 mg, 0.9 mmol) and sodium acetate (118 mg, 1.44 mmol) were added and the mixture heated to 120° C. After 3 h, the mixture was concentrated in vacuo, the residue obtained dissolved in ethyl acetate, and then cooled to 0° C. Ice-water and sodium bicarbonate solution were added then the aqueous layer was extracted with ethyl acetate. The aqueous layer was adjusted to pH 6 with 1M HCl solution and was extracted twice more with ethyl acetate. The combined organic layers were dried over sodium sulfate then concentrated in vacuo. Purification by chromatography (silica, 20 to 70% ethyl acetate in hexanes) gave 2-(1H-pyrrolo[2,3-b]pyridin-6-yl)-isoindole-1,3-dione (179 mg, 75%) as a light brown solid. 1H NMR (300 MHz, DMSO-d6) δ ppm 11.91 (br. s., 1H) 8.15 (d, J=7.9 Hz, 1H) 7.90-8.05 (m, 4H) 7.59-7.65 (m, 1H) 7.21 (d, J=7.9 Hz, 1H) 6.54-6.60 (m, 1H); LCMS (EI/CI) m/z: 264 [M+H].

Provenance & Evidence