a) The peak at 5.86 ppm, corresponding to the amine NH 2 function of the starting material (ABA), which disappeared in the synthesized diazonium salt. b) There is a shift of the aromatic proton peaks (around 2 ppm) and the acid peak that shows the diazonium salt is well synthesized with the N 2 + attractor group. These observations confirm the production of the product of 4-Diazenylbenzoic acid diazonium salt. For second salt; 1H NMR (400 MHz, DMSO) δ (ppm); 2.53 (6H, s), 5.17 (2H, s), 6.57 (2H, s), 6.62 (H, s). And for the diazonium salt synthesized the NH 2 peak is gone and the other peak is shifted to the left: 1H NMR (400 MHz, DMSO) δ (ppm) ; 2.46 (6H, s), 7.95 (2H, s), 8.32 (H, s). Thus, obtaining the DMB salt is confirmed by the disappearance of the peak of the amine NH 2 in the product and removal of the peaks of the aromatic protons.