Simple Bromination of Mepronil Fungicide

Studies on the Residue of Mepronil Fungicide in Crops and Soils (Part 1)

Abstract

For microdetermination of mepronil fungicide, derivatization into a halogenated compound sensitive to electron capture detection was investigated. By a simple procedure it could be brominated to form dibromomepronil which was stable and highly sensitive to the detection. Mepronil reacted with bromine in benzene: methanol (99:1) media under cooling and the reaction completed within 30min. Several mepronil derivatives and other pesticides could also be easily brominated, although numbers of substituted bromine atoms of products varied by compound, indicating that this condition could be applied for the bromination of many other aromatic compounds. Besides, this reaction was more available than those of trifluoroacetylation and pentafluorobenzoylation. It was found that mepronil was very stable against acid and base hydrolysis.