In this study, the computerized molecular docking method was used to investigate the interactions of five nitro diazo dye derivatives 1-5 with COVID-19, CLpro, RAF and PLpro as very important viral proteins to target the coronavirus SARS-CoV-2. Among the used diazo dyes, compound 5 showed the highest binding free energies and the lowest inhibition constants Ki with all studied proteins, and it exhibits a large effect to inhibit the activities of the RAF and COVID-19. Therefore, compound 5 may be useful as an antiviral candidate that worth more trials for COVID-19 disease. The binding sites of compound 5 with the tested viral proteins were evaluated.

Three new amide compounds 6, 8 and 9 were derived from diazo dye 4. 4-Hydroxy-3-methoxy-5-(2,6-dinitrophenyl) benzaldehyde 4 was reacted separately with compounds 5 and 7 to obtain 6 and 8, respectively. The amide compound 9 was synthesized by two different methods. The reaction between 6 and a diacyl chloride compound 7 gave compound 9. Also, compound 9 was produced via the reaction of compound 8 and an N-terminus compound 5. All compounds were characterized by their melting points, UV-Vis, and FTIR spectra. Moreover, the mass spectrum and elemental analysis of compound 9 were determined. All three synthesized compounds were tested against P. mirabilis, E. coli, and S. aureus at different concentrations and showed significant results.