SYNTHESIS OF SOME NEW 3,7-BISUBSTITUTED D IBENZOBROMOLIUM SALTS

3,7-Dinitrodibenzobromolium bisulfate (5) was prepared directly by rea ction of 4,4-dinitrobiphenyl with sodium bromide and potassium persulp hate in concentrated sulphuric acid. Reduction of the compound 5 with SnCl2-HCl gave 3,7-diaminodibenzobromolium chloride (6). Reactions of the diazo-salt solution obtained by diazotisation of the compound 6, w ith Cu2Cl2, Cu2Br2, and KI gave 3,7-dichlorodibenzobromolium chloride (7), 3,7-dibromodibenzobromolium bromide (8), and 3,7-diiododibenzobro molium iodide (9), respectively. Structures of these new compounds (5 similar to 9) were established by H-1 NMR, MS and IR.