Process for manufacturing diphenylamines

Abstract

The invention teaches novel process steps for the rapid high yield manufacture of diphenylamines of the formula wherein R1 is selected from hydrogen, alkyl, and aryl; wherein each R2 and R3 is the same or different and each is independently selected from hydrogen, alkyl, alkoxy, aralkyl, dialkylamino, alkylarylamino and substituted or unsubstituted aryl, the substituents on aryl being each independently selected from alkyl (C1-C8), alkoxy (C1-C8), aroxy, aralkoxy and halogen; wherein n and m are each independently an integer from 1 to 5. Diphenylamines are key intermediates for the production of leuco dyes used in pressure-sensitive and heat-sensitive imaging systems. The process in at least one embodiment comprises reacting at elevated temperature an aryl halide with an aromatic amine in an organic solvent and aqueous alkaline solution and optionally in some embodiments, phase-transfer agent, followed by addition of catalytic amounts of bis[tri(t-butylphosphine)]palladium at a suitable temperature to rapidly form diphenylamine.

Dependencies are inferred from the claim text.