Birch, Stewart, Kolasch & Birch
Process for preparing 6-(substituted phenyl)-4,5-dihydro-3(2H)-pyridazinone compounds
 6-(Substituted phenyl)-4,5-dihydro-3(2H)-pyridazinone compounds possessing strong platelet aggregation inhibiting activity and blood pressure depressing activity, having the general formula: ##STR1## wherein R.sup.1 is hydrogen or lower alkyl; R.sup.2 is hydrogen, lower alkyl, lower alkylthio or the grouping R.sup.5 --NH-- where R.sup.5 is lower alkyl; R.sup.3 is phenyl, pyridyl, benzyl, lower alkyl or a substituted phenyl group carrying at any desired position on the benzene ring thereof the grouping: ##STR2## where R.sup.1 has the same meaning as given above; R.sup.4 is hydrogen or halogen; n is 0 or 1; and when both R.sup.2 and R.sup.3 are lower alkyl groups, R.sup.2 and R.sup.3 may be combined together with the bridging member ##STR3## between them to form the structure: ##STR4## where m is 2 or 3, as well as physiologically acceptable acid-addition salts thereof, and processes for preparing them. 
Mitsui Toatsu Kagaku Kabushiki Kaisha
C C A A C
C07D C07D A61P A61P C07D
inventional inventional inventional inventional inventional
Takuo Tsutomu Nobuyuki Takashi Joji Hajime Yasuhito
Nakano Katakami Fukazawa Nishina Kamiya Iizuka Tanaka