Synthesis, Characterization, and Investigation of Antimicrobial Activities of New Naphthoquinone Compounds from 2-(butylthio)-3-chloronaphthalene-1,4-dione

Abstract

In this study, the compound 2-(butylthio)-3-chloronaphthalene-1,4-dione (3) was synthesized from the reaction of the compound 2,3-dichloro-1,4-naphthoquinone (1) with 1-butanethiol in alkaline medium. The synthesized compound 2-(butylthio)-3-chloronaphthalene-1,4-dione (3) was used as the starting compound. As a result of the nucleophilic substitution of 2-(butylthio)-3-chloronaphthalene-1,4-dione (3) with heterocyclic compounds containing nitrogen, sulfur, and oxygen atoms, a series of 10, 11, 12, 13, 14, 15, naphthoquinone derivative compounds were synthesized. The structures of the synthesized compounds were characterized by FTIR, 13C-NMR, 1H-NMR, and Mass Spectroscopy techniques. The antimicrobial properties of the synthesized compounds were examined by performing antimicrobial studies with Gram-positive and Gram-negative bacteria. The compound 2-(butylthio)-3-chloronaphthalene-1,4-dione (3) shows the highest antimicrobial activity, whereas the compound 2-(butylthio)-3-((4,5-dihydrothiazol-2-yl)thio) naphhalene-1,4-dione (10) exhibits the lowest antimicrobial activity. Compounds 3, 11, 12, 13, 14, and 15 exhibited enhanced activity against Gram-positive bacteria, such as B. subtilis and S. aureus, as well as Gram-negative E. coli and K. pneumoniae. In addition, compounds 11, 12, and 14 exhibited activity against Gram-positive B. subtilis and S. aureus, as well as Gram-negative E. coli, K. pneumoniae, and P. aeruginosa. The study aims to enhance existing literature research and create new unknown compounds through synthesis.