“…21 The solvent was then evaporated and the residue purified using gravity column chromatography on silica gel eluted with ethyl acetate-hexanes (1:1) to provide a 10–15% yield of 3 as deep yellow powder. 1 H-NMR (CDCl 3 , 500 MHz): δ 8.55 (dd, J = 8.5, 1 Hz, 1H), 8.43 (dd, J = 8.5, 1 Hz, 1H), 8.00 (ddd, J = 8.5, 7, 1 Hz, 1H), 7.79 (ddd, J = 8.5, 7, 1 Hz, 1H), 3.14 (tt, J = 8.0, 5.0 Hz, 1H), 1.36 (m, 4H); 13 C-NMR (125 MHz, CDCl 3 ): δ 157.1, 139.0, 135.4, 133.9, 131.1, 121.5, 119.4, 10.1, 9.3; HRMS (ESI) m/z calc for C 10 H 10 N 3 O 2 (M+H + ) 204.0773, found 204.0765.…”