METHOD OF OBTAINING 5(6)-AMINO-2-(4-AMINOPHENYL)BENZIMIDAZOLE FROM 2',4,4'-TRINITROBENZANILIDE Russian patent published in 2015 - IPC C07D235/18 

FIELD: chemistry.

SUBSTANCE: invention deals with method of obtaining 5(6)-amino-2-(4-aminophenyl)benzimidazole by catalytic hydration of 2',4,4'-trinitrobenzanilide in medium of amide solvent from the series: dimethylformamide, dimetylacetamide, N-methylpyrrolidone, with separation of formed 2',4,4'-triaminobenzanilide from hydrolysate in form of monosulphate salt with further cyclodehydration of monosulphate salt of 2',4,4'-triaminobenzanilide with heating in aqueous sulphuric acid, separation of sulphate salt of 5(6)-amino-2-(4-aminophenyl)benzimidazole by its crystallisation and filtration and neutralisation with base, characterised by the fact that separation of monosulphate salt of 2',4,4'-triaminobenzanilide is carried out in presence of lower aliphatic alcohol or acetone and cyclodehydration is carried out in presence of activated coal.

EFFECT: elaborated is novel method of obtaining compound, characterised by higher productivity and low expenditures on reagents.

2 cl, 1 dwg, 4 tbl, 6 ex