Table 3.

¹H-NMR spectral data of 1–3.

Complex	1H NMR (500 MHz: δ, ppm, J in Hz)
1	8.11–8.00 (m, 8H, Ar), 7.55–7.42 (m, 14H, Ar), 7.01 (s, 1H, CH), 6.68 (d, J = 7.8 Hz, 2H, Ar), 6.01 (s, exch., 1H, NH)
2	7.58–7.52 (m, 5H, Ar), 7.05 (s, 1H, CH), 6.74–6.70 (m, 4H, Ar), 5.94 (s, exch., 1H, NH), 1.79 (t, J = 7.4 Hz, 6H, 3CH2), 168 (m, 6H, 3CH2), 1.46 (m, 6H, 3CH2), 1.00 (t, J = 7.4 Hz, 9H, 3Me)
3	8.08–7.66 (m, 12H, Ar), 7.12 (s, 2H, 2CH), 6.68 (d, J = 7.9 Hz, 6H, Ar), 5.95 (s, 2H, exch., 2NH), 1.15 (s, 6H, 2Me).