Synthesis and insecticidal activity of new 3‐benzylfuran‐2‐yl N , N , N ′, N ′‐tetraethyldiamidophosphate derivatives

BACKGROUND: A series of 3‐benzylfuran‐2‐yl N , N , N ′, N ′‐tetraethyldiamidophosphate derivatives were synthesized as potential new agents to control insects. Their structures were confirmed on the basis of IR, NMR and MS analyses. RESULTS: Ten 3‐benzylfuran‐2‐yl N , N , N ′, N ′‐tetraethyl derivatives were prepared from the compound furan‐2‐yl N ′ ( N , N , N ′, N ′‐tetraethyldiamidophosphate). The contact toxicity of all derivatives, at a dose of 10 µg mg −1 insect, was evaluated against four insect species, Ascia monuste orseis Latr. (Lepidoptera: Pyralidae), Diaphania hyalinata (L.) (Lepidoptera: Pyralidae), Sitophilus zeamais Mots. (Coleoptera: Bruchidae) and Solenopsis saevissima (Smith) (Hymenoptera: Formicidae). The mortality range observed for some derivatives, such as 3‐(3‐methylbenzyl)furan‐2‐yl N , N , N ′, N ′‐tetraethyldiamidophosphate (82.5% mortality against D. hyalinata ; 100% mortality against S. saevissima ), was comparable with that of the commercial insecticide chlorpyrifos‐methyl. The biological activity of the derivatives depended on the substitution pattern of the benzylic ring. Furan‐2‐yl N , N , N ′, N ′‐tetraethyldiamidophosphate, furan‐2‐yl N , N ‐diethylamidochlorophosphate and difuran‐2‐yl N , N ‐diethylamidophosphate were also evaluated, displaying, in some cases, activity comparable with that of chlorpyrifos‐methyl (90%, 100% and 97.5% respectively against A. monuste orseis ). Considerable activity was observed for some furan‐2( 5 H )‐ones evaluated. CONCLUSION: Ten 3‐benzylfuran‐2‐yl N , N , N ′, N ′‐tetraethyldiamidophosphate derivatives were synthesized and fully characterized from a chemical point of view. The results obtained from the biological assays indicate that this class of compounds can be utilized for the design of new substances endowed with insecticidal activity. Copyright © 2008 Society of Chemical Industry