METHOD OF PRODUCING SUBSTITUTED 4-HYDROXY-3-OXO-3,4-DIHYDRO-2H-1,4-BENZOXAZINE-6,7-DICARBONITRILES BASED ON 4-BROMO-5-NITROPHTHALONITRILE Russian patent published in 2011 - IPC C07D498/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing substituted 4-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-6,7-dicarbonitriles of general formula: where R=H (a); CH₃ (b); OCH₃ (c); CI (d) which can be used as biologically active substances, fluorescent materials and for synthesis of phthalocyanines. The method involves synthesis of substituted 4-hydroxy-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-6,7-dicarbonitriles through a reaction which takes place in two steps, where at the first step 4-bromo-5-nitrophthalonitrile reacts with sodium salts of substituted 3-phenylpropanoates in molar ratio 1:2, respectively, at temperature 19…25°C for 12-20 hours in dimethyl formamide (DMF) solution, 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, 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 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 novel heterocyclic dicyano-derivatives of benzoxazines.

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