TITLE:
Analyses of Reaction Mechanisms among Different Sulfonation Reagents and m-Diphenylamine and Crystal Structures of the Formed Compounds
AUTHORS:
Dongdong Chen, Chundong Mi, Menglan Yuan, Aiquan Jia, Qian-Feng Zhang
KEYWORDS:
2, 4-Diaminobenzenesulfonic Acid, Sulfur Trioxide (SO3), Spectrometry, Crystal Structure
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.12 No.4,
April
28,
2024
ABSTRACT: In the traditional process, m-phenylenediamine reacts with fuming sulfuric acid at high temperature to get intermediates, and then after dehydration occurs intramolecular rearrangement to get 2,4-diaminobenzenesulfonic acid. Traditional methods need to consume a lot of fuming sulfuric acid or concentrated sulfuric acid, resulting in high industrial large-scale production cost, more waste, and posing a serious environmental pollution risk. In this thesis, three different sulfonation reagents were used for the sulfonation reaction of m-phenylenediamine, and the reaction mechanisms and crystal structures of the three pathways were investigated. The three routes are: 1) one-step synthesis of monosulfonated compound 1 from raw material and sulfur trioxide (SO3); 2) rapid reaction of raw material and chlorosulfonic acid to synthesize bisulfonated compound 2; 3) direct eutectic crystallization of raw material and ordinary sulfuric acid to obtain compound 3. The crystal structure of the compounds synthesized by three paths was analyzed by X-ray single crystal diffraction, and compound 1 was characterized by NMR, Fourier infrared spectra, UV-visible spectrum and Mass spectrometry. The one-step synthesis of SO3 as a sulfonation reagent has the advantages of mild reaction conditions, simple operation and low cost.