The Color Reaction in Non-Aqueous Solvents. VI. The Comparison of Tetrabromobenzaurine with Bromophenol Blue in Non-Aqueous Solvents

We studied in this work the comparison of the reactivity of tetrabromobenzaurine (II) with that of bromophenol blue (I) in methanol-benzene and benzene.We discussed how the bulky aminated sulfone group in the ortho position of I influenced the arrangement of the three phenyls, the approach of anion to a center carbon atom, and the behavior of amines bonded to the phenolic hydroxy group, based on a shift to the longer wave length of II, the fading of II in methanol-benzene, and the comparison of the enthalpies and entropies of the reaction of II with those of I.It was found that the use of. II in the reaction with amines was undoubtedly advantageous over I since an absence of the sulfone group in II resulted in an increase in reactivity of the phenolic hydroxy group with amines and simplification of the reaction.