Caesium bromide, reaction

Reaction of a mixture containing hexafluoroacetone and caesium fluoride with allyl bromide or chloride occurs readily [131, 132] (Figure 8.31) but the mixture does not react with trimethylchlorosilane [131]. 

The first syntheses were developed in the 1980s by Kozo Shiokawa at Nihon Bayer Agrochem. The iminoimidazolidine was formed by reaction of the diamine with cyanogen bromide however, this product could be nitrated on the nitrogen in only poor yields (a). [ 145] Shigeru Kojima prepared imidacloprid by reaction of the diamine with dimethyl nitrocarboimidodithioate in dichloro-methane (b). [146] The best synthesis is probably the reaction of 2-chloro-5-(chloromethyl)pyridine and 2-nitroiminoimidazolidine with potassium carbonate in acetonitrile. [ 147] The reaction may be catalysed by 3-5 mole percent of caesium chloride (c). [148]... 

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