FIELD: organic chemistry. SUBSTANCE: invention describes the novel derivatives of pyrazole of the formula (I) 
where R1 means CN, C1-6-alkoxycarbonyl, phenyl or C1-6-alkyl optionally substituted with one or more halogen atoms; R2 is the group of the formula (II) 
, (III) 
or (IV) 
where R7 is H, halogen atom, tri-(C1-6-alkyl)-silyl, C1-6-alkyl (optionally substituted with one or more halogen atoms, OH, or C1-6-alkoxy-group), C1-6-alkoxycarbonyl, phenyl group or 5- or 6-membered cyclic heterocycle which is saturated partially or completely and has up to 4 heteroatoms taken independently among up to 4 nitrogen atoms, 2 oxygen atoms and 2 sulfur atoms and that is bound to alkyl link by suitable C, S or N atom if valency allows; and R8,R9,R10 each means independently H, halogen atom, phenyl optionally substituted with one or more halogen atom, CN or C1-6-alkyl group optionally substituted with one or more halogen atoms; R3 is H, C1-6-alkyl, NH2, NH-(C1-6-alkanoyl), NH-(C1-6-alkoxycarbonyl), N-(C1-6-alkoxycarbonyl)2, NH-(C1-6-alkyl), N-C1-6, NHCONH-(C1-6/ -alkyl), N-pyrrolyl, SH or S-(O)n(C1-6-alkyl) where n = 0, 1 or 2; and R4,R5,R6 each means independently halogen atom, C1-6-alkyl substituted with one or more halogen atom, C1-6-alkoxy-group substituted with one or more halogen atoms, S-(O)n-(C1-6-alkyl) optionally substituted with one or more halogen atoms where n = 0, 1 or 2 or SF5, or their pharmaceutically acceptable salts. The above indicated compounds show antiparasitic properties. Invention describes also method of treatment of parasitic infection and method of damage or destruction of parasites. EFFECT: enhanced effectiveness of compounds. 16 cl, 1 tbl
