Synthesis Of Fungicide Trifloxystrobin And Key Intermediate

The β-methoxyacrylate fungicides are a new class of respiration inhibitors based on a group of natural products--Strobilurins. They have the characteristics of high efficiency, broad spectrum, low toxicity, short residual and environmentally friendly. Due to their special action mechanism, the research on them has been a hot topic in fungicidal fields, what’s more, this kind of fungicide has occupy the important status in the fungicide world since the first strobilurin-type fungicide launched in1996. This paper described the discovery and the recent development of strobilurins fungicides, some popular products are also introduced. The snythesis process of trifloxystrobin and its key intermediates were studied, It is very important to decrease the effect on the environment and improve the produce-consist of the pesticide in our country.The synthesis of trifloxystrobin was starting from phthalide, which react with bis(trichloromethyl)carbonate to give o-chloromethylbenzoyl chloride, followed by cyanidation with NaCN to give o-chloromethylbenzoyl cyanide, The cyanide was then esterified with methanol oximated with methoxyamine, and finally condensed with 3-(trifluoromethyl) acetopheneone oxime. The total yield of the five-step reactions was38.8%.3-(Trifluoromethyl)acetopheneone oxime was synthesized from3-(Trifluoromethyl)acetophenone and hydroxylammonium chloride in the yield of86.3%. In the ring-opening reaction, thionly chloride and phosgene were replaced by bis (trichloromethyl)carbonate, which improved the safety of the reaction and make the process more cleaner. In the preparation of2-(chloromethyl)benzoyl cyanide, a new catalytic cyanide reaction was investigated, using Sm(OTf)3as the optimized and reuseable catalyst and without use of phase transfer catalyst. Two methods were studied in the synthesis of methyl(E)-2-(chloromethyl)-a-oxyiminobenzeneacetate, and the better result was obtained under higher pressure of HCl gas.In conclusion, an optimized process of trifloxystrobin and its key intermeates was studied, which has such advantages as simple operations, readily available materials, safe conditions and less pollution. This work makes progress in green chemical process and the process is suitable for industrial application.