Synthesis of 6- (Arylamino) -7-Alkylthio -5,8-Quinolinediones for Evaluation of Antifungal Activities

A series of 6-(N-arylamino)-7-alkylthio-5,8-quinolinedione derivatives(SQ1-12) were newly synthesized for the evaluation of antifungal activities. 6-(N-Arylamino)-7-chloro-5,8-quinolinediones (RCKs) were treated with Na$_2$S/(CH$_3$)$_2$SO$_2$ in EtOH In give SQs. RCKs were prepared by regioselective nucleophilic substitution of 6,7-dichloro-5,8-quinolinediones with arylamines. In the presence of CeCl$_3$, the N-arylamino groups were introduced at the 6-position of 5,8-quinolinedione ring by the regioselective substitution. These derivatives 1-12 were tested for antifungal and also antibacterial activities, in vitro, against Candida sp., Aspergillus niger and Trichophyton mentagrophytes. The MIC values were determined by the two-fold dilution method.