| abstract |
Compounds of the formula (1) :n or pharmaceutically acceptable salts thereof as described, whereinn is a pyridine, pyrazine or triazine ring; R¹ is C₁₋₆alkyl, C₂₋₆alkenyl, C₃₋₅cycloalkylC₁₋₆alkyl, or C₁₋₆alkyl substituted by 1 to 6 fluoro groups; R² is C₁₋₆alkylthio, C₁₋₆alkylsulphonyl, C₁₋₆alkoxy, hydroxy, hydrogen, hydrazino, C₁₋₆alkyl, phenyl, -NHCOR³ wherein R³ is hydrogen or C₁₋₆alkyl, or -NR⁴R⁵, wherein R⁴ and R⁵ together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino, hexahydroazepino, morpholino or piperazino ring, or R⁴ and R⁵ are independently hydrogen, C₃₋₅cycloalkyl or C₁₋₆alkyl which is optionally substituted by -CF₃, phenyl, -S(O) n C₁₋₆alkyl wherein n is 0, 1 or 2, -OR⁶, -CO₂R⁷ or -NR⁸R⁹ wherein R⁶ to R⁹ are independently hydrogen or C₁₋₆alkyl, provided that the carbon atom adjacent to the nitrogen atom is not substituted by said -S(O) n C₁₋₆alkyl, -OR⁶ or -NR⁸R⁹ groups; and whenn is a pyrazine ring it may be further substituted by hydroxy when R² is hydroxy. n Their use as medicaments, pharmaceutical compositions comprising them and processes for their preparation are also described. |