The present invention relates to novel heterocyclic compounds of formula I wherein the variables are as defined in the claims or the description, which are useful for inhibiting glycogen synthase kinase 3 (GSK-3), compositions containing the compounds, their use for preparing a medicament for the treatment of a medical disorder susceptible to the treatment with a compound that modulates, preferably inhibits, the activity of glycogen synthase kinase 3&bgr;, and methods of treatment of medical disorders susceptible to treatment with a compound that modulates glycogen synthase kinase 3&bgr; activity using the compounds.