METHOD OF PRODUCING CHLORINE-SUBSTITUTED 4,4-DIAMINOBENZANILIDES Russian patent published in 2010 - IPC C07C233/80 C07C231/12 

FIELD: chemistry.

SUBSTANCE: invention relates to a novel method of producing chlorine-substituted diaminobenzanilides such as 2¹ -chloro-4,4¹-diaminobenzanilide and 2¹,6¹-dichloro-4,4¹-diaminobenzanilide - monomers used in production of heat-resistant, fire-resistant and high-strength fibre. The method involves acylation of 2-chloro-4-nitroaniline or 2,6-dichloro-4-nitroaniline with nitrobenzoyl chloride taken in excesses, using ferric chloride as a catalyst in an organic solvent medium while heating in the presence of an anhydride of 4-nitrobenzoic acid, after which the chlorine-substituted dinitrobenzanilide formed is separated through crystallisation and filtration and reduced in an aqueous solution of an amide solvent with subsequent separation of the chlorine-substituted dinitrobenzanilide through crystallisation and filtration. After separating the chlorine-substituted dinitrobenzanilide or chlorine-substituted diaminobenzanilide, the mother solution is completely or partially returned to the corresponding process stage.

EFFECT: method enables to achieve high output (86-95%) of chlorine-substituted 4,4¹-diaminobenzanilides and minimise amount of wastes.

5 cl, 22 ex, 1 tbl