FORMATION OF ANILINE MONOSULPHONIC ACID
الملخص
The study of aniline sulfonation is important for the subsequent synthesis of polyaniline with substituents in the side chain. Sulfonation of purified aniline monosulfate with monohydrate and oleums was used. Quantitative analysis of aminosulfonic acid isomers was carried out using spectrophotometric and bromometric methods. An increase in the SO3 concentration in the sulfonating oleum leads to an increase in the amount of methanilic acid compared to the ortho- and para-isomers. The process of increasing the concentration of the meta-isomer is a linear function of the acidity of the oleum. The addition of tetrabisulfate boric acid to the oleum also helps to increase the yield of methanilic acid. A comparison of activation energies showed that tetrabisulfate boric acid had no effect on the sulfonation mechanism and the transition state. The work presents new data on the mechanisms of aniline sulfonation.