COCRYSTALLINE FORM OF 2,8-DIMETHYL-5-PHENETHYL-2,3,4,5-TETRAHYDRO-1H-PYRIDO[4,3-b]INDOLE Russian patent published in 2023 - IPC C07D471/04 C07D213/55 

FIELD: pharmaceuticals.

SUBSTANCE: invention relates to a method of producing a cocrystalline form of 2,8-dimethyl-5-phenethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole with nicotinic acid of formula II at a molar ratio of 2,8- dimethyl-5-phenethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole and nicotinic acid in a 1:1 cocrystal and the following parameters: orthorhombic cells, C₂₇H₂₉N₃O₂ at 20°C:

F(000) = 913, unit cell parameters and intensities of 19,604 reflections measured (6.32° ≤ 2Θ ≤ 49.98°), 4002 independent (R_int = 0.1028, R_sigma = 0.0964), final R₁ = 0.0625 (I>=2σ (I)) and wR₂ = 0.1882, taking into consideration that 2,8-dimethyl-5-phenethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole hydrochloride is treated with equimolar aqueous alkali solution NaOH and the resulting free base 2,8-dimethyl-5-phenethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole is mixed with an equimolar amount of nicotinic acid, Ethyl acetate is added to the mixture as a solvent and subjected to mechanical activation by grinding, followed by evaporation of the solvent residue.

EFFECT: method of obtaining a cocrystalline form of 2,8-dimethyl-5-phenethyl-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole with nicotinic acid which can find its application in medicine for the production of pharmaceuticals for the treatment of neurodegenerative diseases and associated depressive episodes, including in the treatment of Alzheimer's disease.

1 cl, 3 dwg, 2 tbl, 2 ex