The invention is directed to physiologically active compounds of generalformula (I): wherein R1 is lower alkyl, R2 is aryl, arylalkyl, heteroaryl orheteroarylalkyl, or R1 and R2 together with the nitrogen atom to which theyare attached form a cyclic amine, Ar1 is aryldiyl or heteroaryldiyl, Ar2 isoptionally substituted phenylene or heteroaryldiyl, L1 is an a -R5-R6- linkagewhere R5 is alkylene, alkenylene or alkynylene and R6 is a direct bond,cycloalkylene, heterocycloalkylene, arylene, heteroaryldiyl, -C(=Z1)-NR4-, -NR4-C(=Z1)-, -Z1-, -C(=O)-, -C(=NOR4)-, -NR4-, -NR4-C(=Z1)-NR4-, -SO2-NR4-, -NR4-SO2-, -O-C(=O)-, -C(=O)-O-, -NR4-C(=O)-O- or -O-C(=O)-NR4-, L2 is a directbond, an optionally substituted alkylene, alkenylene, alkynylene,cycloalkenylene, cycloalkylene, heteroaryldiyl, heterocycloalkylene oraryldiyl linkage, a -[C(=O)-N(R9)-C(R4)(R10)]p-linkage, a-Z3-R11-linkage, a -C(=O)-CH2-C(=O)- linkage or a -R11-Z3-R11- linkage, and Y is carboxy or anacid bioisostere； and the corresponding N-oxides, and their prodrugs； andpharmaceutically acceptable salts and solvates (e.g. hydrates) of suchcompounds and their N-oxides and prodrugs. Such compounds have valuablepharmaceutical properties, in particular the ability to regulate theinteraction of VCAM-1 and fibronectin with the integrin VLA-4(.alpha.4.beta.1).
