The first method: Since the reaction of aryl halides with primary aromatic amines produces not only diaryl amines but also triaryl amines, the reaction of p-iodotoluene and p-toluidine to produce Di-p-tolylamine simultaneously generates a large amount of 4,4',4''-trimethyltriphenylamine. The second method: Di-p-tolylamine is prepared by acylation of p-toluidine followed by reaction with p-iodotoluene, and finally hydrolysis. This reaction overcomes the shortcomings of the direct reaction between aryl halides and primary aromatic amines; although the yield is low, it does not produce 4,4',4''-trimethyltriphenylamine.
Di-p-tolylamine (also known as 4,4′-dimethyldiphenylamine) is an intermediate for OLED materials. Acting as a strong electron-donating unit, Di-p-tolylamine is chemically incorporated into the molecular framework of the host material POPCPA, and is used to fabricate highly efficient blue phosphorescent OLED devices with low driving voltages (maximum power efficiency of 45.3 lm/W; driving voltage of 2.6 V at 1 cd/m2). This compound shares a similar diphenylamine structure to that found in commonly used hole-transporting materials (such as TAPC); the methyl-substituted diphenylamine unit possesses good electron-donating ability and steric hindrance, which helps to increase the material's glass transition temperature (90°C) and thermal decomposition temperature (406°C), thereby enhancing the thermal stability of the device[1].
4,4''-Dimethyldiphenylamine is a reagent used in the comparative studies of the analgesic and anti-inflammatory properties of N-phenylanthranilic acids and mefenamic acid, and the anti parasitic activities of some substituted diphenylamines.
[1] Shaolong Gong. (2014). High-Power-Efficiency Blue Electrophosphorescence Enabled by the Synergistic Combination of Phosphine-Oxide-Based Host and Electron-Transporting Materials. Chemistry of Materials, 26 3, 1463–1470. https://doi.org/
10.1021/cm4037555
