PYRIDO[3,4-D]PYRIMIDINE DERIVATIVE AND ITS PHARMACEUTICALLY ACCEPTABLE SALT Russian patent published in 2023 - IPC C07D471/04 C07D519/00 A61K31/519 A61K31/5377 A61K31/541 A61K31/55 A61K31/551 A61K31/553 A61P9/10 A61P11/00 A61P19/02 A61P29/00 A61P43/00 A61P35/00 

FIELD: pharmaceuticals.

SUBSTANCE: invention relates to a compound having formula (I), where R¹ represents C_3-12 cycloalkyl, C_4-12 cycloalkenyl, 4-9-membered heterocyclyl, C_6-10 aryl or 5-6-membered heteroaryl, where each 4-9 membered heterocyclyl represented by R¹ contains one to two heteroatoms independently selected from oxygen, sulfur and nitrogen atoms, where each 5-6 membered heteroaryl represented by R¹ is independently selected from furanyl, thienyl and pyridyl, R¹ is optionally substituted with 1-6 substituents selected from the group comprising halogen, =O, -OH, -CN, -COOH, -COOR⁶, -R⁷ and C_3-6 cycloalkyl; R⁶ and R⁷ are each independently C_1-6 alkyl; R² is C_1-8 alkyl, 4-5 membered heterocyclyl, C_1-8 acyl, -COOR⁸ or -CONR⁹ R¹⁰, where each of the C_1-8 alkyls represented by R² is independently substituted with 1-2-OH groups, 1-2 C_1-8 alkoxy groups, or 1-5 fluorine atoms; with the proviso that R² is neither unsubstituted C_1-8 alkyl nor a trifluoromethyl group; each of R⁸, R⁹ and R¹⁰ independently represents a hydrogen atom or C_1-8 alkyl; each heterocyclyl group represented by R² is oxetanyl or tetrahydrofuranyl; R³ represents a hydrogen atom or C_1-8 alkyl; X represents CR¹¹ or a nitrogen atom; R¹¹ represents a hydrogen atom or C_1-6 alkyl; R⁴ is -A¹-A²-A³ ; A¹ is a single bond or C_1-8 alkylene; 1 sp³ carbon atom at any position in A¹ may optionally be independently replaced by 1 structure selected from the group comprising [-O-, -NR¹⁴-, -C(=O)-]; A² is a single bond, C_1-7 alkylene, C_3-12 cycloalkylene; A³ represents -R²⁵, -OR²⁶, with the proviso that A³ is -R²⁵ if A¹ moiety on the side of A² is [-O-, -NR¹⁴-, -C(=O)-], and A² is a single bond; or a pharmaceutically acceptable salt thereof. The invention also relates to intermediate compounds represented by formulas (II), (III), (IV), where R¹, R², R³ and Z, n are given in the claims. The invention relates to a pharmaceutical composition having an inhibitory effect on CDK4/6 containing an effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.

EFFECT: pyrido[3,4-d]pyrimidine derivatives and pharmaceutically acceptable salts thereof with an inhibitory effect on cyclin-dependent kinase 4 and/or cyclin-dependent kinase 6 ("CDK4/6") that can be used for prophylaxis or treatment of rheumatoid arthritis.

21 cl, 111 tbl, 24 ex