The invention relates to compounds of the formula 1 ##STR00001## or pharmaceutically acceptable salts, prodrugs, solvates or hydrates thereof, wherein wherein X, R.sup.1, and R.sup.2 are as defined herein. The invention also relates to pharmaceutical compositions containing the compounds of formula 1 and to methods of treating hyperproliferative disorders in a mammal by administering the compounds of formula 1.