| abstract |
Compounds of formula (I), (R₁, R₂, R₃, R4, X, Y and Z are as defined in the description), or pharmaceutically acceptable salt or ether, provided that the compound is not 2-benzyl-7-bromine-6-nitrobenzene furan-4,5-diol, pharmaceutical composition comprising them and use thereof as a medicinal means for treatment of such diseases or conditions in which COMT inhibitor is prescribed. |