METHOD OF PRODUCING 3-SUBSTITUTED 2-AMINO-1-HYDROXY-5,6-DICYANOINDOLES BASED ON 4-BROMO-5-NITROPHTHALONITRILE Russian patent published in 2011 - IPC C07D209/40 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing 3-substituted 2-amino-1-hydroxy-5,6-dicyanoindoles of general formula: where R denotes H(a); CH₃(b); OCH₃(c); Cl(d); F(e), comprising a first step where 4-bromo-5-nitrophthalonitrile reacts with a sodium salt of 2-substituted oxobutenitrile in molar ratio 1:2, respectively, at temperature T=19…25°C for 1-2 hours in a dimethyl formamide (DMF), after which the reaction mass is diluted with tenfold excess water with T=0…25°C. The released resinous residue is extracted with dichloromethane, thoroughly washed with water and chromatographed on silica gel. The eluent (solvent) is evaporated. The residue of the intermediate product is filtered and re-crystallised from alcohol. At the second step of the method, the tin dichloride solution in concentrated hydrochloric acid is mixed with the solution of the obtained intermediate product in ethyl alcohol in molar ratio 3.5-4.5:1, respectively, at temperature T=30…50°C and reaction time of 1-2 hours, after which the reaction mixture is diluted with tenfold excess water with T=0…25°C, and the precipitate is filtered and re-crystallised from alcohol.

EFFECT: obtaining desired products with output of 69-81% which can be used in synthesis of biologically active substances, fluorescent materials and phthalocyanines.

1 dwg, 1 tbl, 5 ex