Synthesis and Antifungal Activity of Some Synthetic Halides Derived from 4-Aza-1-azoniabicyclo[2,2,2]octane Against Sheath Blight (Rhizoctonia solani Kuhn) of Rice

A series of 1-(alkyl/alkenyl/alkynyl/aryl)-4-aza-1-azoniabicyclo[2,2,2]octane halides were synthesized by the reaction of 1,4-diazabicyclo [2,2,2]octane with corresponding alkyl/alkenyl/alkynyl/aryl halides. The monoquaternary structures were confirmed by estimation of their halide contents. These were screened on rice inoculated with Rhizoctonia solani Kuhn in a pot culture experiment by spraying aqueous solutions (1000 mg ml⁻¹) at maximum tillering stage. All the test salts exhibited fungicidal activity. 1-Propyl-4-aza-1-azoniabicyclo-[2,2,2]-octane bromide was most active. Structure-activity relationship revealed that C₃-alkyl chain was optimum in such quaternary salts. Unsaturation of alkyl chain led to decrease in the activity.