“…(E)-3,4,5-trihydroxy-N'-(3-hydroxybenzylidene)benzohydrazide ( 20 ) ( Taha et al., 2019 ):- Yield (%): 54%; m.p. °C: 145–147; IR: 3465 (OH), 3340 (N-H), 1695 (C=O), 1616 (C=N),1460 (C=C Ar ring), 1318 (C-O), 1248 (N-N); 1 H-NMR (1:1 DMSO-d 6 /CDCl 3 , 400 MHz): δ 9.45–8.26 (m, 5H), 7.35–6.80 (m,7H); 13 C-NMR (1:1 DMSO-d 6 /CDCl 3 , 100 MHz): δ 166.7 (C=O), 161.4 (N=CH), 157.4 (C-O), 145.0 (C-O), 137.7 (C-O), 134.9 (C-O), 129.5 (CH), 120.1 (Ar C CH=N), 119.8 (CH), 118.5 (CH), 114.4 (Ar C -C=O), 109.0 (2xCH) ppm.…”