Synthesis and Structural Analysis of Some New Sulfanyl Amino 1,4- Naphthoquinone Derivatives

Abstract

In this study, some new sulfanyl-substituted amino 1,4-naphthoquinone derivativeswhich possess two electron-donating groups in the amino fragment were synthesized and theirstructures were analyzed by spectroscopic techniques. First, 2-chloro-3-[(2,4-dimethoxyphenyl)amino]naphthalene-1,4-dione (3a) and 2-chloro-3-[(3,5-dimethoxyphenyl)amino]naphthalene-1,4-dione (3b) were obtained from the reactions ofdichloro-1,4-naphthoquinone (1) with 2,4-dimethoxyaniline and 3,5-dimethoxyaniline. In thefollowing step, the compounds 3a,b were reacted with aliphatic nucleophiles; ethyl-, 1-propyl-,and 1-pentyl mercaptan. S-nucleophiles attacked the carbon atom of 1,4-naphthoquinone coreand displaced the chlorine atom to create target molecules; 2-arylamino-3-(ethylthio)naphthalene-1,4-dione (5a,b), 2-arylamino-3-(propylthio)naphthalene-1,4-dione(5c,d), 2-arylamino-3-(pentylthio)naphthalene-1,4-dione (5e,f) derivatives. The structures ofthe synthesized compounds were elucidated by utilizing 1D and 2D NMR techniques withadditional spectroscopic data (mass and FTIR).