Abstract
A grindstone method based on Mannich condensation was used to synthesize geranylacetone derivatives (1a-1f). The method showed a high yield under milder reaction conditions. Analyses of the synthesized compounds were carried out by FTIR, H-1, C-13 NMR, mass spectrometry, and elemental analysis. We synthesized and evaluated the larvicidal and ichthyotoxic activities of six compounds (1a-1f) in this study. Compound 1f (5,9-dimethyl-1-phenyl-3-(2-(3-phenylallylidene)hydrazinyl)deca-4,8-dien-1-one) was more active (LD50: 14.1 mu g/mL) against the second instar larvae of Culex quinquefasciatus than geranylacetone (67.2 mu g/mL), whereas the former caused 13.9% mortality at 100 mu g/mL. Geranylacetone, in an antifeedant screening test, showed 53.1% against Oreochromis mossambicus within 24 h. The compound 1f showed high larvicidal activity against C. quinquefasciatus and was non-toxic to non-target aquatic species.