Study On The Synthetic Process Of Flonicamid

Pesticides are an important part of modern agriculture, the neonicotinoid insecticides are becoming a hot research topic in recent years. Neonicotinoid insecticides with novel structure, unique mechanism of action, broad spectrum, high efficiency, low toxicity, low residue, high selectivity, environmental protection, have been developed vigorously. Flonicamid is a novel fluorine-containing neonicotinoid insecticides. With further research on the synthesis process and application technology, flonicamid has a more broad application prospects in agricultural production in our country. This dissertation is focused on process research synthesis of flonicamid.In the present paper, synthetic methods of flonicamid and its key intermediate 4-trifluoromethylnicotin acid were reviewed and compared in detail. Two synthetic routes of 4-trifluoromethylnicotin acid were screened out for further research. 4-Trifluoromethylnicotin acid was synthesized from tert-butyl vinyl ether via acylation, ammonolysis, condensation, cyclization, hydrolysis, nucleophilic substitution and electrophilic addition. Under the optimal condition, the total yield was 21.1% and the purity was 98.79%. Meanwhile the problems in each step involved in the synthesis process and side reactions were studied and discussed in detail. The synthetic process has some advantages of high yield, simple operation and high purity, and is suitable for industrial production. The chemical structures of 4-trifluoromethylnicotin acid and its intermediates had been characterized by 1H-NMR.