The present invention relates to compounds of formula 1 ##STR00001## or
pharmaceutically acceptable salts thereof, wherein one of R.sup.1 and
R.sup.2 is methyl, ethyl or isopropyl, and the other is H; R.sup.3 and
R.sup.4 are each independently H, branched or unbranched C.sub.1-C.sub.6
alkyl, or aryl, and wherein at least one of R.sup.3 and R.sup.4 is other
than H; R.sup.5 is a branched or unbranched C.sub.1-C.sub.5 alkyl group
or a C.sub.1-C.sub.6 cycloalkyl group, each of which may be optionally
substituted with one or more OH groups; R.sup.6, R.sup.7, R.sup.8 and
R.sup.9 are each independently H, halogen, NO.sub.2, OH, OMe, CN,
NH.sub.2, COOH, CONH.sub.2, or SO.sub.2NH.sub.2.A further aspect of the
invention relates to pharmaceutical compositions comprising compounds of
formula 1, and the use of said compounds in treating proliferative
disorders, viral disorders, stroke, alopecia, CNS disorders,
neurodegenerative disorders, or diabetes.