Compounds of general formula I R 1 is selected from any one of phenyl, furanyl, and pyrrolyl, wherein each of phenyl, pyrrolyl, and furanyl may optionally and independently be substituted by 1 or 2 substituents selected from CF 3 , methyl, chloro, fluoro, bromo, and iodo R 2 is independently selected from ethyl and isopropyl R 3 is independently selected from hydrogen and fluoro and R 4 is -NH 2 or salts thereof or separate enantiomers and salts thereof are disclosed and claimed in the present application, as well as separate enantiomers of the compounds and salts and pharmaceutical compositions comprising the novel compounds and their use in therapy, in particular in the management of pain, anxiety and functional gastrointestinal disorders.
