[Studies on as-triazine derivatives. XVIII. Synthesis of 5,6-diaryl-1,2,4-triazine derivatives as blood platelet aggregation inhibitors].
5,6-Diphenyl-, 3,5-diphenyl-, and 3,6-diphenyl-1,2,4-triazine (as-triazine) derivatives were evaluated for inhibitory activity towards arachidonic acid-induced aggregation of rabbit blood platelet in vitro. Among the isomers, 5,6-diphenyl-as-triazine derivatives were active, therefore a phenyl substituent on the as-triazine ring at the 5- and 6-position was essential for the inhibitory activity. Thus, various 3-substituted 5,6-diaryl-as-triazines were synthesized by the nucleophilic substitution reaction of 5,6-diaryl-3-methylsulfonyl-as-triazines with O,N,C-nucleophiles. In the case of as-triazines having different aryl groups at the 5- and 6-positions, the compounds were prepared by the step-wise addition reaction of Grignard reagents with 3-methylthio-as-triazine. Among these compounds, ethyl 5-(4-methoxyphenyl)-6-phenyl-as-triazine-3-acetate (24a) and ethyl 5,6-bis(4-methoxyphenyl)-as-triazine-3-acetate (24f) showed the most potent inhibitory activity, which was almost equal to the activity of anitrazafen.
Konno
S
S
Pharmaceutical Institute, Tohoku University, Sendai, Japan.
Kokubo
T
T
Amano
M
M
Yoshida
N
N
Sagi
M
M
Yamanaka
H
H
D000818:Animals; D016718:Arachidonic Acid / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D010975:Platelet Aggregation Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D011817:Rabbits; D013329:Structure-Activity Relationship; D014227:Triazines / Q000138:chemical synthesis* / Q000494:pharmacology
D010975:Platelet Aggregation Inhibitors; D014227:Triazines; D016718:Arachidonic Acid