Cyanogenation s. Replacement

According to Werner s theory (see this series, Vol. X.), the formulae of hydrogen ferro- and ferri-cyanide should be written [Fe(CN)6]H4 and [Fe(CN)6]H3 respectively, the six cyanogen groups being co-ordinated with the iron atom, and constituting the nucleus around which hover the replaceable hydrogen atoms. 

Cyanogen and ca-bromoacetophenone give di-imino-dihydroquimxaline and a phenyl-dihydroquinoxaline respectively. If the diketones are replaced by monocarbonyl compounds such as aldol, crotonie aldehyde, benzaldehyde, o- and p-anisaldehydes or iiiperonal, arsenated Schiff s bases result, e.g. 

S. Conversely, the members of the acetic series may be converted into those of the succinic containing cme atom of carbon more, by replacing one atom of the methylic hydrogen in aBetie acid by cyanogen, and then boiling with potaseio hydrate... 

Little preparative importance attaches to conversion of organic sulfides into chloro compounds The fission of compounds R-S-R by chlorine, bromine, cyanogen bromide, and methyl iodide, with replacement of C-S by C-halogen bonds has been reviewed by Tarbell and Harnish.1287 The action of 1 mole of bromine on thioacetals in an anhydrous medium (ether) at room temperature affords bromo hemiacetals (a-bromo sulfides) and a sulfenyl bromide, and bromo sugars analogously from ethyl thioglycosides. 

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