| abstract |
A compound of formula (I) wherein R1 is phenyl substituted by one or more halogen atoms; R2 is -NH¿2; R?3 is -NH¿2? or hydrogen; R?4¿ is -CXNRaRb, -CXNH-(CH¿2?)y-NR?aRb¿; wherein X is = O or = S; y is an integer zero, 1 or 2; R?a and Rb¿, which may be the same or different, are selected from hydrogen and C¿1-4? alkyl or together with the nitrogen atom to which they are attached form a saturated 5- or 6-membered heterocycle containing one or two nitrogen heteroatoms, which heterocycle can be further substituted with one or more C1-4 alkyl groups; and pharmaceutically acceptable derivatives thereof. |