Síntese e avaliação da atividade inseticida de novos fosforamidatos

• Autor(a) principal: Oliveira, Fabrício Marques de
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2142
• topic: Inseticidas; Fosforamidatos; Organofosfatos; Insecticidal; Phosphoramidates; Organophosphates; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA

The compounds known as phosphoramidates are characterized for possessing at least one NR1R2 group (R1 and R2 = alkyl, aryl) in their structures. Several reports in the literature have described the insecticidal activity of this class of organophosphates. In the present investigation, a series of four phosphoramidates were synthesized and biologically evaluated with regard to their potential insecticidal activity. In addition, other fifteen phosphoramidates, previously described in the literature, had their insecticidal activity profile re-evaluated in further details. The synthesis of the new phosphoramidates used as the starting material the lactone furan-2(5H)-one, a compound readily available from furfuraldehyde. Treatment of this lactone with phosphorylchoride in the presence of triethyl amine afforded the compound furan-2-yl phosphorodichloridrate, which was not isolated. Subsequent reaction of this furane with pertinent amines in the presence of catalytic amounts of DMAP resulted in the formation of furan-2-yl N,N-diisopropylamidochlorophosphate, furan-2-yl N,N´-dicyclohexylamidophosphate, furan-2-yl dipiperidin-1-ylphosphinate, and difuran-2-yl piperidin-1-ylphosphonate. The contact toxicity of the organophosphates was evaluated on four insect species of economic importance [Diaphania nitidalis (L.) (Lepidoptera: Crambidae), Diaphania hyalinata (L.) (Lepidoptera: Crambidae), Plutella xylostella (L.) (Lepidoptera: Plutellidae) e Ascia monuste orseis (Latr.) (Lepidoptera: Pieridae)] as well as on a predator [Solenopsis saevissima (F. Smith) (Hymenoptera: Formicidae)] and on a polinizator agent [Tetragonisca angustula (Latr.) (Hymenoptera: Apidae: Meliponinae)]. All the biological assays were conducted at a dose of 1μg of compound/mg of insect. Among the evaluated compounds, the best results were achieved with the four new organophosphates synthesized. In this case, the compounds furan-2-yl N,N-diisopropylamidochlorophosphate and difuran-2-yl piperidin-1-ylphosphonate displayed activity against A. monuste (mortality range higher than 87.50%) comparable with methylchlorpiriphos used as control.