| abstract |
The invention relates to compounds of the general formula wherein R 1 is selected from phenyl, pyridinyl, thiophenyl, furanyl, imidazolyl, each phenyl and heteroaromatic ring being optionally and independently optionally substituted by one, two or three substituents selected from straight and branched C1-C6 alkyl, NO2, CF3, C1-C6 alkoxy, chlorine, fluorine, bromine and iodine, as well as to their pharmaceutically acceptable salts, pharmaceutical compositions containing the compounds, and to their use in therapy, in particular for effecting pain. |