Pyridazinones as beta-adrenoceptor antagonists.

摘要

Compounds of the formula (1):

and pharmaceutically acceptable salts thereof, wherein R<1> is isopropyl or tertiary-butyl;
R<2> is hydrogen, C1-4alkyl, C1-4alkoxy, hydroxy or amino;
and
R<3> hydrogen or methyl; are described for use as beta -adrenoceptor antagonists. Pharmaceutical compositions containing them are disclosed as are processes for their preparation and intermediates therefor.