Potassium Cyanide → 2'-Oxo-1'-pentyl-1',2'-dihydrospiro[furo[2,3-f][1,3]benzodioxole-7,3'-indole]-4'-carbonitrile

Participants

Reaction Steps

A mixture of 4′-bromo-1′-pentylspiro[furo[2,3-f][1,3]benzodioxole-7,3′-indol]-2′(1′H)-one (0.10 g, 0.23 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.21 g, 0.23 mmol) and 2-(di-tert-butylphosphino)biphenyl (0.07, 0.23 mmol), tributyltin cyanide (0.07 g, 0.23 mmol) and potassium cyanide (0.02 g, 0.23 mmol) was purged with nitrogen and anhydrous acetonitrile (10.0 mL) was added. The reaction mixture was refluxed for 16 h. After cooling down to ambient temperature, the reaction mixture was diluted with ethyl acetate (20.0 mL), washed with water (20.0 mL), brine (20.0 mL), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo to dryness. The brown residue was subjected to column chromatography eluting with ethyl acetate/hexane (65%) to give the title compound (0.03 g, 33%) which was recrystallized from ether to get a colorless solid: mp 128-129° C.; 1H NMR (300 MHz, CDCl3) δ 9.10 (s, 1H), 7.42-7.37 (m, 1H), 7.29-7.27 (m, 1H), 7.09 (d, 1H), 6.53 (s, 1H), 6.03 (s, 1H), 5.87 (dd, 2H), 4.91 (q, 2H), 3.86-3.63 (m, 2H), 1.74-1.62 (m, 2H), 1.43-1.26 (m, 4H), 0.89 (t, 3H); 13C NMR (75 MHz, CDCl3) δ 176.5, 157.1, 149.5, 143.5, 142.4, 135.4, 129.7, 128.3, 126.4, 116.3, 114.8, 112.3, 108.8, 102.2, 93.7, 78.7, 58.3, 40.6, 28.9, 26.7, 22.2, 13.9; MS (ES+) m/z 377.5 (M+1).

Provenance & Evidence