METHOD OF PRODUCING N-ALKYL-N'-PHENYL-PARA-PHENYLENEDIAMINES Russian patent published in 2013 - IPC C07C209/26 C07C209/36 C07C211/55 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing N-alkyl-N'-n-phenylenediamines of general formula 1, where: R₁, R₂ are alkyl substitutes. The method involves reducing alkylation of 4-nitrodiphenylamine (4-NDPA) with aliphatic ketones of general formula R₁-CO-R₂, where R₁, R₂ are C₁-C₁₀ alkyl substitutes, in the presence of hydrogen deposited on a granular carbon support of a palladium catalyst Pd/C and a monobasic aliphatic carboxylic acid R"COOH, where: R"=C_nH_2n+1, n=1-4, in the medium of a solvent - monoatomic saturated alcohol R'OH, where; R' is a C₃-C₂₀ alkyl substitute. Content of palladium in the supported catalyst is equal to 0.4-0.6 wt %. The process is usually carried out at temperature of 50-190°C. The molar ratio of catalyst (with respect to Pd) to 4-NDPA ranges from 0.05:1 to 0.1:1, molar ratio of 4-NDPA to the aliphatic ketone is 1:5-1:10, molar ratio of the monobasic aliphatic carboxylic acid to 4-NDPA is 0.036:1-0.1:1 and molar ratio of 4-NDPA to the solvent is 0.25:1 -0.4:1. Hydrogen pressure in the process is equal to 40-60 atm. The obtained N-alkyl-N'-phenyl-n-phenylenediamines have general formula 1

,

where: R₁, R₂ are alkyl substitutes. The method simplifies the process by reducing the amount of precious metals and improves separation of products at the end of the process. High output of the end product and selectivity of the process are preserved.

EFFECT: high quality with high gas chromatography purity.

7 cl, 3 ex