FIELD: organic chemistry, medicine, pharmacy.
SUBSTANCE: invention relates to novel compounds of the formula (I): 
wherein R1 is chosen from group consisting of hydrogen atom (H), halogen atom and oxygen atom (O); R2 is chosen from consisting of H, halogen atom and N=N; R3 is chosen from group consisting of H and halogen atom; R4 is chosen from group consisting of H, halogen atom, amino and N=N; R5 is chosen from group consisting of H, halogen atom, methoxy, methyl and O; or R1 and R2, or R and R5 are joined and form unsaturated carbon ring; R6 is chosen from group consisting of H, (C1-C6)-alkyl, (C2-C6)-alkenyl, 3-phenyl-2-propin-1-yl, benzyl, benzyl substituted with halogen atom, phenyl or methoxy, CH2-cycloalkyl, CH2-2-furan, -(CH2)2SCH3 and -(CH2)2NHBOC; R7 is chosen from group consisting of H, (C1-C6)-alkyl and cycloalkyl; R8 is chosen from group consisting of benzyl and benzyl substituted with OCH2-phenyl; T represents group of the formula 
or 
wherein R9 and R10 represent H; or R9 represents H, and R10 are chosen from group consisting of (C1-C6)-alkyl, (C2-C6)-alkenyl, methyl-substituted (C2-C6)-alkenyl, (C2-C6)-alkynyl, cycloalkyl, phenyl substituted with (C1-C6)-alkyl, halogen atom, methoxy, -SCH3 or -N(CH3)2, 1-naphthyl and CH2-CH2-1,3-dioxolane; or R9 and R10 are chosen independently from group consisting of (C1-C6)-alkyl, (C2-C6)-alkenyl, phenyl, phenyl substituted at position 4 with halogen atom, methoxy, -SCH3 or -N(CH3)2 and 1-naphthyl, or its pharmaceutically acceptable salt, hydrate, or its prodrug as carbamate or ester. Also, invention relates to compounds of the formula (Ia) and the formula (Ib) given in the invention description, and to a method for decreasing levels of beta-amyloid, and to their using and to a method for prophylaxis or treatment of Alzheimer's disease, Down's syndrome. Invention provides preparing novel biologically active compounds.
EFFECT: valuable medicinal properties of compounds and pharmaceutical composition.
30 cl, 17 tbl, 278 ex
