Microwave enhanced solid support synthesis of fluorine containing benzopyrano-triazolo-thiadiazepines as potent anti-fungal agents

A facile, dry media procedure has been developed for the synthesis of a series of a new class of fluorine containing 3-alkyl-7-chloro-11a,12-dihydro-11-phenyl-12-(substituted aryl)-11H-benzopyrano4,3-e]1,2,4]-triazolo3,4-b]1,3,4]-thiadiazepines (4a-k) under microwaves using basic alumina as solid support. The reaction time has been brought down from hours (60-65 h) to minutes (3-5 min) with improved yield as compared to conventional method, demonstrating the versatility of the process. The method reported herein is devoid of the hazards of solution-phase reactions. The synthesized compounds have been screened 'in vitro' for anti-fungal activity against Rhizoctonia solani, Fusarium oxysporum and Collectotrichum capsici. Most of the compounds have shown good activity against these pathogens.