METHOD OF PRODUCING CRYSTALLINE FORM OF HEPATITIS B VIRUS SURFACE ANTIGEN INHIBITOR Russian patent published in 2024 - IPC C07D498/04 A61K31/5365 A61P31/20 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing crystalline form A of a compound of formula (I), which is characterized by a powder X-ray diffraction pattern containing characteristic diffraction peaks at the following angle θ: 6.30±0.20°, 9.30±0.20°, 9.84±0.20°, 18.68±0.20°, 20.16±0.20°, 23.06±0.20°, 24.00±0.20° and 25.38±0.20°. Method involves adding a compound of formula (I) in any form to methanol, acetone, ethyl acetate, acetonitrile, an acetonitrile-water mixture at ratio of 1:1 or a mixture of acetone-water at ratio of 1:1, mixing mixture for 1 to 72 hours at temperature of 25 to 65°C. Mixture is then cooled to room temperature, filtered and the precipitate is dried on the filter to obtain crystalline form A. Weight ratio of the compound of formula (I) to the solvent is selected from 1:1–30.

EFFECT: obtaining crystalline form A of the compound of formula (I), characterized by good physical stability and chemical stability.

9 cl, 4 dwg, 8 tbl, 6 ex