The present invention relates to compounds of formula (I)
wherein:
R1 and R2 are each independently H, alkyl or haloalkyl;
R3 and R4 are each independently H, alkyl, haloalkyl or aryl;
R5 is alkyl or cycloalkyl or cycloalkyl-alkyl, each of which may be optionally substituted with one or more OH groups;
R6 is selected from cyclopropylamino, cyclopropylmethylamino, cyclobutylamino, cyclobutylmethylamino and
where one of X, Y and Z is N and the remainder are CR9;
R7, R8 and each R9 are independently H, alkyl or haloalkyl, wherein at least one of R7,
R8 and each R9 is other than H.
A further aspect of the invention relates to pharmaceutical compositions comprising compounds of formula (I), and the use of said compounds in treating proliferative disorders, viral disorders, stroke, alopecia, CNS disorders, neurodegenerative disorders, or diabetes.