Insect antifeedant potent 9H-fluorenacylbromides

Background: Attempts to produce greener bromination of 2-acetyl 9H-fluorene with KBr+KBrO3 reagent using fly-ash:H2O catalyst in aqueous media gave 9H-fluorenacylbromides. Generally, the halo-keto compounds possess insect antifeedant activities. Therefore, the insect antifeedant activities of these acyl bromides have been studied using 4th instar larvae Achoea janata L against castor semilooper. Methods: Solvent free bromination method was used for synthesizing some 9H-fluorenacylbromides. They were characterized by UV, IR, NMR and mass spectroscopic data. Castor-leaf discs were used for evaluation of insect antifeedant activities of the synthesized acyl bromides. Results: The yields of synthesized acyl bromides were over 60%. The physical constants, analytical and spectral data of these ketones has been determined. Halo substituted acyl bromides gave good insect antifeedant activities. Conclusion: Easy handling, non-hazardous and environmentally benign bromination methods have been adopted for synthesizing acyl bromides with good yields. Bromo substituted acyl bromides show better insect antifeedant activity.