FIELD: medicine, pharmaceutics.SUBSTANCE: invention refers to a phenylpyrazol derivative presented by formula (1) or to its pharmaceutically acceptable salt: wherein R1 and R2, which may be identical or different, each represents C1-C6 alkyl, or R1 and R2 are coupled together with an adjacent nitrogen atom to form a 5-6-merous saturated heterocylic ring (wherein the mentioned saturated heterocylic ring may be substituted by halogen or C1-C6 alkyl), n represents an integer 0 to 2, T represents a hydrogen atom, halogen or C1-C6 alkyl, and R has one of formulas (I)-(V), (VII) or (VIII):(wherein Z1 and Z2, which may be identical or different, each represents -CH2-, -O- or -NR11-, p represents an integer 0 to 3, q represents an integer 0 to 1, r and s which may be identical or different, which represents an integer 0 to 2, R3 represents halogen, C1-C6 alkyl, or hydroxy, R4 and R5 which may be identical or different, each represents a hydrogen atom, C1-C6 alkyl (wherein said C1-C6 alkyl may be substituted by hydroxy, hydroxy- C1-C6 alkoxy, C2-C7 alkoxycarbonyl or carboxy), or formula -(CH2)m-Ar1 (wherein Ar1 represents wherein (wherein said phenyl is substituted by halogen or C1-C6 alkyl), and m represents an integer 0 to 1), R6 represents oxo, R7 represents a hydrogen atom or C1-C6 alkyl, R8 represents C1-C6 alkyl (wherein said C1-C6 alkyl may be substituted by halogen), C1-C6 alkoxy (wherein said C1-C6 alkoxy is substituted by halogen) or formula -(CH2)1-Ar2 (wherein Ar2 represents phenyl (wherein said phenyl is substituted by C1-C6 alkoxy, hydroxyl or cyano) or pyridinyl, and 1 represents an integer O to 1), G represents -CO- or -SO2-, R9 represents C1-C6 alkyl, C1-C6 alkoxy, phenyl (wherein said phenyl may be substituted by halogen or pyridinyl, and R11 represents C1-C6 alkyl)}.EFFECT: there are produced new compounds and a preventive or therapeutic agent on the basis of said compounds which can find application in medicine for treating dementia, Alzheimer's disease,
