The Study On Nucleophilic Addition Of Hydrofluoromethy Isoxazoles With Aldehydes

This paper focused on the synthesis of difluoromethyl additived isoxazoles stating from bromodifluoromethylβ-diketones. The reaction of bromodifluoromethylβ-diketones with triethyl phosphite gave stable intermediates in 73.6-81.2% yields. By furthure reaction of the intermediates with hydroxylamine hyhrochloride, hydrogen difuoromethylisoxazoles were obtained in yields of 63.7-73.2% respectively.This paper also studied on the reaction of hydrofluoromethylisoxazoles with aldehydes. Studies have shown that the reactions produce two different locations to replace the product, so to find out the best conditions of the reaction that the hydrogen fluoromethylisoxazoles with the aldehydes. There are some other hydrogenfluoromethyl isoxazoles reacted extended substrate, respectively, under the optimum conditions with benzaldehyde, furfural, anise aldehyde, cinnamic aldehyde, trifluoromethyl benzene formaldehyde reaction to 36.3%-76.4% of the yield to be a series of nucleophilic compounds 6 and isoxazole ring 4-substituted compounds 7. Shows that the optimal reaction conditions for that type of reaction has a good applicability of the different substrates used in the area also has good selectivity. And reaction mechanism was discussed.