4-(1-芐基-1H-吲唑-3-基)苯甲酸乙酯(YD-3)是本實驗室近期所合成出來，作為一個新型的凝血酶-受體拮抗劑。 在此研究中，著者將YD-3當作為一個先導化合物，並製備出一系列的YD-3衍生物(9a—9d, 10a—10n)。 其關鍵的中間產物YD-3之合成如圖表6所述。以4-苯醯基苯甲酸乙酯(3)為起始物質與芐基聯胺反應即可產生4-(芐基腙苯基甲基)苯甲酸乙酯(4)，其產物為E-及Z-型異構物的混合物。將此混合物於低溫下，與四醋酸鉛於二氯甲烷中進行反應後，再加入三氟化硼參與反應，進而加熱即可形成所預期的高產率化合物YD-3。 以YD-3為起始物，合成了不同的酯類(9a—9d)與醯胺類(10a—10n)化合物，提供抗血小板活性試驗的篩選。; Ethyl 4-(1-benzyl-1H-indazol-3-yl)benzoate (YD-3) was first synthesized in our laboratory as a novel thrombin-receptor antagonist. In this study, YD-3 was used as a lead compound and a series of its derivatives (9a—9d, 10a—10n) were prepared. The key intermediate YD-3, was synthesized according to Scheme 6. The starting material ethyl 4-benzoylbenzoate (3) was treated with benzylhydrazine to yield ethyl 4-[(benzylhydrazono)(phenyl)methyl] benzoate (4) as a mixture of E- and Z-form isomers. The hydrazone was then treated with lead tetraacetate in dichloromethane at low emperature, subsequently boron trifluoride etherate was added and the mixture was heated to form the expected YD-3 with high yield. Starting from YD-3, various esters (9a—9d) and amides (10a—10n) were synthesized and examined for antiplatelet screening.
