Compounds of formula (I):
wherein:
R
1
represents hydrogen, a halogen or alkyl,
R
1a
represents hydrogen or alkyl,
R
2
represents hydrogen, a halogen or hydroxy,
A represents NR
4
,
R
3
represents hydrogen, alkyl or cycloalkyl,
R
4
represents hydrogen or alkyl, X is as defined in the description, their isomers, and also addition salts thereof. Medicinal products containing the same which are useful in treating disorders of the AMPA system.