METHOD OF PRODUCING 5-, 6-AMINO-FLUORESCEINS Russian patent published in 2020 - IPC C07D493/10 

FIELD: medicine; chemistry.

SUBSTANCE: invention relates to organic chemistry and medicine, namely to a method of producing 5- and 6-aminofluoresceins by reacting 4-nitrophthalic acid with resorcinol taken in molar ratio 1:2, flowing in medium of orthophosphoric acid, taken in ratio to weight of 4-nitrophthalic acid as 1:2.5 (weight ratio of orthophosphoric acid – 1.75 g/ml) at temperature of 135 °C to form mixture of 5- and 6-nitrofluoresceine isomers and its separation and separation through formation of 5- and 6-nitrofluorescein dipropionates, followed by reduction of each of them to form corresponding amine derivatives, characterized by that in order to separate a mixture of isomers of nitrofluorescein (5- and 6-), propionic anhydride is used in amount of 1:8, which is mixed with a mixture of isomers, the obtained mixture is boiled for 2.5 hours, cooled, filtered and deposited 5-nitrofluorescein dipropionate is washed with ethyl alcohol, dried and subjected to boiling in aqueous solution of sodium sulphide, taken in molar ratio 1:3.3 to 5-nitrofluorescein dipropionate, and 5-aminofluorescein is recovered, and separated after filtration mother solution containing 6-nitrofluorescein dipropionate, treated with distilled water to obtain oily residue, it is crystallized by grinding, crystalline precipitate is separated by filtration and washed with ethanol, dried and recrystallised from benzene, after which obtained 6-nitrofluorescein dipropionate is also subjected to boiling in aqueous solution of sodium sulphide, taken in molar ratio 1:3.3 to 6-nitrofluoresceine dipropionate and isolating 6-aminofluorescein.

EFFECT: described is a method of producing which eliminates use of the opioid series as a precursor in production of drugs, which makes the method more readily available for mass production of fluorescein nitrated derivative; these compounds can be used in synthesis of various fluorescent compounds, such as 5-isothiocyanate of fluorescein (FITC), fluorescein lysicol (CFL), 5-[4,6-dichlorotriazinyl] aminofluorescein (5-DATF) used in medicine for diagnosis and treatment diseases.

1 cl, 1 ex