| abstract |
Compounds of formula (I) in which A represents aryl or heteroaryl or heterocyclyl respectively substituted where appropriate, R1 represents hydrogen or C1-C3 alkyl, R2 represents hydrogen or C1-C3 alkyl, R3 represents hydrogen or C1-C3 alkyl, R4 represents hydrogen or C1-C3 alkyl, X represents N or CH, Y represents CN or NO2, Z represents CH2, O, S, SO, SO2 or NR5, and R5 represents hydrogen or C1-C3 alkyl. |