Disclosed are compounds of the formula (I), wherein R1, R2, R3, R4, R5, R6, R7 and m are as described herein, as modulators of the nicotinic acetylcholine receptors, particularly the α7 subtype, their tautomeric forms, stereoisomers, and their pharmaceutically acceptable salts, pharmaceutical compositions thereof, and combinations thereof with suitable other medicaments. Also disclosed are a process of preparation of the compounds and the intended uses thereof in therapy, particularly in the prophylaxis and/or treatment of disorders such as Alzheimer's disease, mild cognitive impairment, and senile dementia.