“…13 C NMR (126 MHz, DMSO- d 6 ) δ 145.71, 136.89, 133.01, 129.79, 127.97, 127.85, 127.64, 124.49, 119.64, 110.97, 51.15. The results are in agreement to those in the literature . ESI–MS: 341.15 m / z [C 20 H 16 N 6 + H], 379.10 m / z [C 20 H 16 N 6 + K].…”