Method for treating Alzheimers disease, Parkinsons disease, Huntingtons chorea or Picks disease by administering to a patient a compound of formula (I) wherein R1 represents hydrogen R2 represents hydrogen, a C1-C6 alkyl group or C3-C6 cycloalkyl group A represents nitrogen D represents a methylene group, a methyl methylene group, a halogen atom substituted methylene group or a halogen substituted methyl methylene group E represents CH2, CHR3 wherein R3 represents a C1-C6 alkyl group, CH or a carbon atom substituted by a C1-C6 alkyl group Arom represents aryl, aryl having from 1 to 3 identical or different substituent groups selected from halogen, C1-C6 alkyl, and C1-C6 alkyloxy, heteroaryl or heteroaryl having from 1 to 3 substituent groups, selected from halogen, C1-C6 alkyl and C1-C6 alkyloxy. The part represented by is a single bond or double bond.
