Triethylsilane → 6-[2-(dimethylamino)ethoxy]spiro[1-benzofuran-3,3'-indol]-2'(1'H)-one

Participants

Reaction Steps

A mixture of 6-[2-(dimethylamino)ethoxy]-1′-(diphenylmethyl)spiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (0.75 g, 1.5 mmol), triethylsilane (1.3 mL, 8.2 mmol) and trifluoroacetic acid (10 mL) was refluxed for 3 h. The mixture was concentrated under vacuum, and the residue was treated with diethyl ether/hexanes to afford 6-[2-(dimethylamino)ethoxy]spiro[1-benzofuran-3,3′-indol]-2′(1′H)-one (0.52 g, 99%) as a colorless solid: mp 95-97° C.; 1H NMR (300 MHz, DMSO-d6) δ 10.58 (s, 1H), 7.21 (td, J=7.6, 1.3 Hz, 1H), 7.04 (d, J=6.4 Hz, 1H), 6.97-6.84 (m, 2H), 6.64-6.57 (m, 2H), 6.40 (dd, J=8.3, 2.3 Hz, 1H), 4.79 (d, J=9.3 Hz, 1H), 4.67 (d, J=9.3 Hz, 1H), 4.25 (t, J=4.7 Hz, 2H), 3.45 (t, J=4.7 Hz, 2H), 2.81 (s, 6H); 13C NMR (75 MHz, DMSO-d6) δ 178.9, 162.1, 159.5, 142.3, 133.1, 129.2, 124.2, 124.1, 122.8, 122.7, 110.3, 108.2, 97.5, 80.4, 62.9, 57.6, 55.7, 43.2; MS (ES+) m/z 325.2 (M+1).

Provenance & Evidence