Designing Synthetic Pathways for Several 2-Thio-Substituted-3H-Phenothiazin-3-ones in Preparation for Testing in Treatment of Central Nervous System Disorders

Abstract

This paper investigates possible synthetic pathways for two 2-thio-substituted-3H-phenothiazin-3-ones (7). A two step reaction in which 1,4-benzoquinone (1) is first reacted with an alkylthiol (2) in the presence of sodium periodate (NaIO4) and then treated with 2-aminothiophenol (5) followed by a second oxidation with sodium periodate was demonstrated to be effective in synthesizing 2-(phenylthio)-3H-phenothiazin-3-one (12). The same synthetic approach was shown to be ineffective in the synthesis of 2-(cyclopentylthio)-3H-phenothiazin-3-one (16) due to the fact that the first step was incapable of synthesizing 2-(cyclopentylthio)-1,4-benzoquinone (14). Several other synthetic routes were also proven to be ineffective. This investigation is part of a larger effort to create a vast library of 2-thio-substituted-3H-phenothiazin-3-ones (7) for testing in leukotriene inhibition and treatment of neurodegenerative disorders