3(2H)-PYRIDAZINONE DERIVATIVES AND PHARMACEUTICAL COMPOSITIONS CONTAINING THESE COMPOUNDS

摘要

The invention relates to R-2-[3-([1,4]benzodioxan-2-ylmethylamino)-1-propyl] - 3(2H)-pyridazinone of formula (1), and to S-2-[3-([1,4)benzodioxan-2-ylmethylamino)-1-propyl]-3(2H)-pyridazinone of formula (2), and to acid-addition salts thereof as well as pharmaceutical compositions containing these compounds. Furthermore, the invention relates to a process for the preparation of the above compounds. The new starting compounds of formulae (4) and (5) are also involved in the scope of the invention. The compounds according to the invention possess .alpha.1- and .alpha.2-adrenoceptor antagonistic effects and urogenital selectivity. Thus, they are useful for t he treatment of the benign prostate hyperplasia.