PYRAZINE COMPOUNDS

摘要

A compound of formula (I) wherein R<1> is selected from the group consisting of phenyl substituted by one or more halogen atoms, naphthyl and naphthyl substituted by one or more halogen atoms; R<2> is selected from the group consisting of -NH2 and -NHC(=O)R; R<3> is selected from the group consisting of -NRR, -NHC(=O)R and hydrogen, R<4> is selected from the group consisting of hydrogen, -C1-4 alkyl, -C1-4 alkyl substituted by one or more halogen atoms, -CN, -CH2OH, -CH2OR and -CH2S(O)x R; wherein R represents C1-4 alkyl or C3-7cycloalkyl, and R and R, 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 6-membered nitrogen containing heterocycle, which heterocycle can be further susbtituted with one or more C1-4 alkyl; R is selected from C1-4 alkyl or C1-4 alkyl substituted by one or more halogen atoms; x is an integer zero, one or two; and pharmaceutically acceptable derivatives thereof; with the proviso that R<1> does not represent (a); when R<2> is -NH2, and both R<3> and R<4> are hydrogen.