Compounds of formula I, wherein R1-8are as defined in the claims, exhibita positive allosteric GABAB modulator effect and are thus useful aspositive allosteric modulators of the GABABreceptor.本發明係關於式I化合物,其中R1至R8如申請專利範圍所定義;該等式I化合物展現正向異位GABAB調節作用且因此適用作GABAB受體之正向異位調節劑。