The invention relates to substituted 2-alkylsulfanyl-3-(arylsulfonyl)-cycloalkyl[e and d]pyrazolo[1,5-a]pyrimidines, to serotonin 5-HT6 receptor antagonists, to novel drug substances and pharmaceutical compositions, comprising the said conpounds as active ingredients, to novel medicaments and methods for treatment and prophylaxis of CNS diseases of humans and warm blooded animals pathogenesis of which is associated with 5-HT6 receptors.In general formulas 1 and 2R1 represents hydrogen or C1-C3 alkyl； R2 represents C1-C3 alkyl； R3 represents hydrogen, one or more optionally identical halogens, C1-C3 alkyl or hydroxyl optionally substituted with C1-C3 alkyl； n represents the whole numbers 1, 2 or 3.
