A series of 4-(2-chlorophenyl)-9-methyl-6H-thieno [3, 2-f][1, 2, 4] triazolo [4, 3-a][1, 4] diazepine derivatives bearing substituents at the 2-and 6-positions were synthesized, and evaluated in vitro for their inhibitory activity on rabbit platelet aggregation induced by platelet activating factor (PAF) and in vivo for their preventing effect on PAF-induced mortality in mice. The length of alkyl or arylalkyl side chain at the 2-position was responsible for ...
