METHOD OF PRODUCING 2-CHLORO-1,4-PHENYLENEDIAMINE Russian patent published in 2024 - IPC C07C209/36 C07C209/84 C07C209/86 C07B31/00 C07C209/90 C07C211/52 

FIELD: chemical or physical processes.

SUBSTANCE: invention relates to production of chlorine-substituted phenylenediamines, which can be used as a promising starting product for synthesis of monomers, used for heat-resistant high-strength fibers, films and varnishes. Method of producing 2-chloro-1,4-phenylenediamine by reduction of 2-chloro-4-nitroaniline with iron powder in aqueous hydrochloric acid medium at 90–100 °C with subsequent precipitation and separation of iron sludge by hot filtration, extraction of end product by crystallization and drying, is characterized by the fact that reduction process is carried out at molar ratio of components of iron, hydrochloric acid and 2-chloro-4-nitroaniline, respectively 2.71–3.2:0.20–0.24:1. Before precipitation of iron sludge, soda ash, activated carbon and sodium sulphite are added to the reaction mass, target product is separated directly from filtrate after separation of iron sludge, wherein activated carbon is added in amount of 2.0–2.5 wt.% to initial 2-chloro-4-nitroaniline, sodium sulphite is added in amount of 0.75–0.93 wt.% to initial 2-chloro-4-nitroaniline, and all steps of obtaining the product are carried out in a nitrogen atmosphere.

EFFECT: simplifying the technology of producing the end product while maintaining its quality.

4 cl, 1 tbl, 8 ex