“…[14] Spectroscopic data: 1 H NMR (400 MHz, DMSO-d6) δ 8.30 (bs, 2H), 7.35–7.29 (m, 5H), 5.10–5.03 (m, 2H) 4.73 (t, 1H, J=6.89Hz), 3.63 (s, 3H) 3.32–3.26 (m, 2H), 2.91 (s, 3H); 13 C NMR (400 MHz, DMSO-d6) δ 169.74, 156.68, 137.17, 129.09, 128.41, 128.10, 67.55, 59.22, 53.15, 38.11, 34.85; MS (ESI positive ion mode) exact mass calculated for C 13 H 18 N 2 O 4 : 266.13, found (M+H) + : 267.09.…”