Compounds

A compound of formula I:

• wherein:
• A is
• D is oxygen or sulfur;
• E is a single bond, oxygen, sulfur, or NR10;
• Ar1 is a 5-membered heteroaromatic ring containing one, oxygen atom;
• Ar2 is a phenyl or a 5- or 6-membered aromatic or heteroaromatic ring containing 1, 2 or 3 atoms selected from nitrogen, oxygen or sulfur atoms, wherein there is no more than 2 oxygen or sulfur atom;
• or naphthyl or an 8-, 9- or 10-membered fused aromatic or heteroaromatic ring system containing 1, 2 or 3 nitrogen, oxygen or sulfur atoms, wherein there is no more than 2 oxygen or sulfur atoms;
• wherein the aromatic rings Ar1 and Ar2 are substituted with 0, 1, 2 or 3 substituents selected from halogen, C1-4alkyl, C2-4alkenyl, C2-4alkynyl, CN, NO2, NR1R2, CH2NR1R2, OR3, CH2OR3, CO2R4 and CF3;
• but if Ar1 is phenyl and Ar2 is quinolynyl, then Ar2 is substituted with 0, 1, 2 or 3 substituents selected from C1-4-alkyl, C2-4alkenyl, C2-4alkynyl, CN, NO2, NR1R2, CH2NR1R2, OR3, CH2OR3 and CO2R4;
• R1, R2, and R3 are independently C1-4alkyl, aryl, heteroaryl, C(O)R5, C(O)NHR6, C(O)R7, SO2R8;
• or R1and R2 may together be (CH2)jG(CH2)k where G is oxygen, sulfur, NR9, or a single bond;
• j is 2, 3 or 4;
• k is 0, 1 or 2;
• R4, R5, R6, R7, R8, R9, and R10 are independently C1-4alkyl, aryl, or heteroaryl;
• or an enantiomer thereof or pharmaceutically-acceptable salts thereof;
• with the proviso that:
• if D represents oxygen, E represents a single bond, and A represents:
• and Ar2 represents a pyrazole ring, then all optional substituents on the pyrazole ring shall be hydrogen.