Compounds of general formula (Ia), (Ib) and (II), wherein R1 and R2 each independently signify hydrogen, lower alkyl, lower alkoxy, nitro, trifluoromethyl, amino, halogen, cyano or R3 R4 NS(O)2 -- and R3 and R4 signify lower alkyl, and R2 can additionally signify morpholino or thiomorpholino, a 5- or 6-membered heterocycle with 1-3N atoms optionally substituted by lower alkyl, hydroxy, amino or the group --CH2 NHCH3, a bicyclic heterocycle with 1-3N atoms or a group --NR5 R6 or --OR5 in which R5 and R6 can be the same or different and signify hydrogen, lower alkyl, hydroxy-lower alkyl, lower alkoxy-lower alkyl, amino-lower alkyl or lower alkylamino-lower alkyl, and X in formula (II) signifies --CH=CH--, --CH=N--, --NH--, --CO-- or --O--, as well as pharmaceutically usable salts of compounds of general formula (Ia), (Ib) and (II). They can be used for the treatment or prevention of illnesses, especially for the treatment or prevention of ischemia, hypoglycaemia, hypoxia, cerebral vascular spasms, spasticity, trauma, hemorrhagia, infection (viral, bacterial, amoebic, prional), epileptic seizures, autoimmune diseases, withdrawal symptoms, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, intoxications, olivoponto-cerebellar atrophy, spinal cord injuries, schizophrenia, depressions, anxiety states, dependence, pains,autism and mental retardation.
