PYRAZINE COMPOUNDS

摘要

A compound of formula (I) wherein R<1> is phenyl substituted by one or more halogen atoms; R<2> is -NH2; R<3> is -NH2 or hydrogen; R<4> is -CXNR<a>R<b>, -CXNH-(CH2)y-NR<a>R<b>; wherein X is = O or = S; y is an integer zero, 1 or 2; R<a> and R<b>, which may be the same or different, are selected from hydrogen and C1-4 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.