| abstract |
A compound is provided that is useful as a pharmaceutical composition for the prevention and / or treatment of schizophrenia, cognitive damage associated with schizophrenia (CIAS), cognitive impairment, fragile X syndrome, autism spectrum disorder, spasticity, anxiety disorder, substance addiction, pain, fibromyalgia, Charcot-Marie-Tooth syndrome, or similar conditions that have positive allosteric modulating effect (PAM action) of GABAB, in turn a sulfur-containing bicyclic compound is a PAM of a GABAB receptor. Claim 1: A compound of the formula (1) or a salt thereof, in the formula, X is CH; R¹ is lower alkyl; R² is lower alkyl, where R¹ and R² can form a cycloalkane together with the carbon atoms to which they bind; R³ is -H; R⁴ is -H; ring A a cyclohexane ring; RY is -NRARB; RA and RB form cyclic amino that may be substituted, together with a nitrogen atom to which they bind; wherein the cyclic amino is a group represented by the formula (2) where Y is NH, O, S, S (= O) ₂ or CH₂; and RL is lower alkyl. |