Water → 3-amino-1'-(pyridin-2-ylmethyl)spiro[furo[3,2-f][1,2]benzisoxazole-5,3'-indol]-2'(1'H)-one

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Reaction Steps

To a stirred solution of 6-fluoro-2′-oxo-1′-(pyridin-2-ylmethyl)-1′,2′-dihydrospiro[1-benzofuran-3,3′-indole]-5-carbonitrile (0.40 g, 2.7 mol) and acetohydroxamic acid (0.60 g, 8.0 mmol) in N,N-dimethylformamide (20 mL) was added cesium carbonate (2.60 g, 8.0 mmol). The reaction mixture was stirred at ambient temperature for 18 h and water was added. The aqueous phase was extracted with ethyl acetate. The combined organic extracts were washed with water and brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo. The residue was purified by column chromatography and eluted with (ethyl acetate/hexanes (2/3)+0.1% v/v 7 N methanolic ammonia) to afford 3-amino-1′-(pyridin-2-ylmethyl)spiro[furo[3,2-f][1,2]benzisoxazole-5,3′-indol]-2′(1′H)-one (0.05 g, 5%): mp 190-192° C. (ethyl acetate/hexanes); 1H NMR (300 MHz, DMSO-d6) δ 8.54-8.52 (m, 1H), 7.79-7.73 (m, 1H), 7.35-7.20 (m, 5H), 7.08-6.96 (m, 3H), 6.15 (s, 2H), 5.09-4.85 (m, 4H); 13C NMR (75 MHz, DMSO-d6) δ 177.2, 164.2, 163.3, 158.7, 155.6, 149.9, 143.5, 137.6, 131.7, 129.4, 126.4, 124.5, 123.6, 123.1, 121.9, 116.8, 111.5, 109.9, 91.4, 81.0, 56.8, 45.3; MS (ES+) m/z 384.9 (M+1).

Provenance & Evidence