SYNTHESIS, CHARACTERIZATION AND ANTIFUNGAL ACTIVITY OF QUINAZOLINE THIONE DERIVATIVES OF 3, 4-DIHYDRO-1(2H)-NAPHTHALENONE

Abstract

A series of 2-substituted benzylidene-tetralone was prepared from 6-methoxy-tetralone by using an Aldol condensation and then these synthesized benzylidene-tetralone derivatives were further condensed with thiourea to give various substituted quinazoline thione derivatives. All of these compounds have been characterized by IR, NMR and Mass spectral analysis for structure establishment and further evaluated for their antifungal activity against Aspergillus niger (MTCC-282) and Candida albicans (MTCC-227) by agar diffusion method using fluconazole as standard drug. Among 6-methoxy-benzylidiene derivatives; C1, C2, C7 were least active and C3, C4, C5, C6 were moderately active while among quinazoline thione derivatives; C8, C9 were least active and C10, C11, C12, C13 were moderately active. When electron-withdrawing substitutions were made on both ring antifungal activity increased in (NO2 > F> Cl) order. The maximum zone of inhibition (60.7 % and 69.7 %) was shown by compound C5 among 6-methoxy-benzylidiene derivative and C11 had (72 % and 73 %) activity among quinazoline thione derivative against Aspergillus niger and Candida albicans respectively.