The present invention relates to novel compounds of the general formula
(I)
##STR00001##
wherein R.sup.1, R.sup.4, R.sup.5 and X are as defined,having a positive
allosteric GABA.sub.B receptor (GBR) modulator effect, methods for the
preparation of said compounds and to their use, optionally in combination
with a GABA.sub.B agonist, for the inhibition of transient lower
esophageal sphincter relaxations, for the treatment of gastroesophageal
reflux disease, as well as for the treatment of functional
gastrointestinal disorders and irritable bowel syndrome (IBS).