METHOD OF PRODUCING CHLORINE-SUBSTITUTED PHENYLENEDIAMINES Russian patent published in 2015 - IPC C07C209/36 C07C211/51 

FIELD: chemistry.

SUBSTANCE: method is carried out by reducing corresponding chlorine-substituted nitroanilines or dinitrobenzenes in a solvent medium. A solution of the reduction products is treated with mineral acid (hydrochloric, sulphuric or phosphoric acid or with hydrogen chloride gas) and the obtained salt of the mineral acid is converted into a base by treating with an alkaline agent in the presence of an antioxidant (sodium sulphite, potassium sulphite or sodium pyrosulphite). The desired compound is separated by extraction and crystallisation. The solvent used in the reduction process is water, dimethylacetamide or a mixture of dimethyl formamide with water, methyl alcohol, ethyl alcohol, isopropyl alcohol, ethyl acetate, benzene or toluene. The reduction process is carried out using hydrogen in the presence of a catalyst: platinum or palladium or another platinum group metal on a support, or palladium which is modified with nickel or iron on a support, or a skeleton nickel or nickel-chromium catalyst. Alternatively, reduction is carried out using iron in an aqueous solvent in the presence of an electrolyte.

EFFECT: improved method of producing chlorine-substituted phenylenediamines, which enables to obtain end products of high quality by preventing oxidation and formation of packing products during separation.

8 cl, 1 tbl, 13 ex