| abstract |
Oxadiazoles represented by structural formula I:n or a salt or prodrug thereof; wherein none of X, Y or Z is an oxygen atom and the other two are nitrogen atoms, and the dotted circle represents aromaticity (two double bonds); nR² represents a substituent of low lipophilicity; nthe broken line represents an optional chemical bond; and nthe substituents R³ and R⁴ may be present at any position, including the point of attachment to the oxadiazole ring, and R³ represents halo, C₁₋₄ alkoxy, carboxy, -NR⁷R⁸, C₂₋₄ alkyl, C₁₋₄ alkyl substituted with hydroxy or C₁₋₄ alkoxy, or methyl or hydroxy in the 3-, 4- or 5-position; and R⁴ represents hydrogen, halo, C₁₋₄ alkoxy, hydroxy, carboxy, -NR⁷R⁸, C₁₋₄ alkyl, or C₁₋₄ alkyl substituted with hydroxy or C₁₋₄ alkoxy; or R³ and R⁴ together represent carbonyl; and nR⁷ and R⁸ independently represent hydrogen or C₁₋₂ alkyl nare potent muscarinic agonists with good CNS penetrability, and are therefore useful in the treatment of neurological and mental illnesses; the compounds are also of benefit in the treatment of severe painful conditions. Processes for preparing these compounds are described, as also are pharmaceutical compositions containing them. |