- 學位論文
利用查爾酮合成一系列吡唑、吡唑啉的衍生物
Synthesis of a series of pyrazolines and pyrazoles from chalcone
摘要
查爾酮類(chalcones)化合物廣泛地存在自然界中，它們具有良好的抗氧化的生理活性，因此常作為生物體內自由基的清除劑、氧化酶抑制劑及抗癌藥物等等。 吡唑(pyrazole)結構類的化合物在天然物中也可以發現，有許多的文獻都有記載著此化合物的藥物活性，它們常常被使用在殺蟲劑或是除草劑等的農用化學品；在醫藥用化學上則具有止痛、消炎、肌肉放鬆、抗痙攣等等的效果，而較著名的藥品例如塞來昔布類具有緩解骨關節炎及風濕性關節炎的症狀、利莫那班類對於胰島素這類的內分泌有控制的作用、西地那非類具有治療男性性功能障礙以及肺動脈高壓等等的效果。 合成吡唑的方法為以查爾酮(chalcone)為起始物，加入聯氨(Hydrazine)形成吡唑啉(Pyrazoline)，再以2,3-二氯-5,6-二氰對苯醌(DDQ)進行氧化而得到最終產物吡唑。本篇透過推、拉電子基兩者位置的不同以及合成異惡唑對產率的影響。 合成吡唑啉時發現所有間位的化合物以及鄰位的甲氧基最不穩定，而其他位置的吡唑啉在溶劑下皆會分解。若使用醋酸為溶劑，將吡唑氮上的氫以乙醯取代，但所形成的化合物無法進一步被氧化而不能形成吡唑。
並列摘要
Flavonols are naturally occurring molecules. They are recognized as good antioxidants. Many Flavonols are used for reactive oxygen species scavengers, oxidase, inhibitors and anticancer drugs. Pyrazole are discovered in natural plants and considered as pain relieving and muscle relaxation. A number of pyrazole derivates are famous for their efficacy and these drugs display different mechanisms of actions. For example, Celecoxib demonstrates anti-inflammatory; Rimonabant is used to treat obesity; Sildenafil is used to treat erectile dysfunction and pulmonary arterial hypertension. A series of chalcones were used for start material, then treated with hydrazine to obtain pyrazolines. The obtaining pyrazoline were oxidated by DDQ to afford pyrazoles. The yields of pyrazoles were variated with the electron-donating and electron-withdrawing groups in aromatic rings. The pyrazolines were deteriorated in solvent, furthermore, the m- and o- methoxy compounds are particularly unstable.