A new versatile strategy for design and synthesis of reduced risk fungicides: Bibenzyl core incorporated with modified as-indacene

Abstract

A novel montmorillonite K 10 clay catalyzed Michael addition followed by dehydrative cyclization in one-pot has been designed to synthesize 4,4<i style="">'</i>-bis(4<i style="">"</i>,8<i style="">"</i>-aryl-1<i style="">"</i>,4<i style="">"</i>-dihydro-bisthiazolo[3,2-a;5<i style="">'"</i>,4<i style="">'"</i>-e]pyrimidine-2<i style="">"</i>-thion-1<i style="">"</i>-yl)bibenzyls <b style="">6a-j</b> with excel­lent yield under microwave irradiation in solvent-free conditions. This eliminates a series of complex isolation procedures and often minimizes the use of large amount of expensive, toxic and hazardous solvents after each step. This procedure reduces reaction time, cost and enhances yield. It realizes integrated chemical process for library synthesis of bioactive compounds. Compounds <b style="">5a–j </b>and <b style="">6a–j</b> have been evaluated <i style="">in-vitro</i> for their fungitoxicities against <i style="">Fusarium oxysporum</i> and <i style="">Penicillium citrinum</i>. The fact that both of these fungus have developed resistance to several fungicide groups made them optimal candidates as target organisms for ongoing research about the potential application of as-indacene and analogue compounds as reduced-risk fungicides.