Publication: Bazı 6,7-dihidroksi-3-fenilkumarin türevi makrohalkalı eterlerin sentezi
Abstract
Kumarinler, doğal bileşiklerdir ve özellikle bitkilerin çiçeklerinde serbest veya glukozidleri halinde bulunurlar. Bu bileşikler, sinnamik asit ve kafeik asitlerle yapısal benzerlik göstermektedirler. o-Dihidroksisinnamik asidin yan zincirinin laktonlaşmasi ile kumarin türevleri oluşur. Biyolojik aktiviteleri nedeniyle son yillarda önem kazanmişlardir. Ayrica o-dihidroksikumarinler, kumarin-taç eter türevlerinin sentezi için gerekli olan bileşiklerdir ve bunlarin kompleks oluşturma özelliklerinden dolayi günümüzde önemi gittikçe artan taç eter türevleri sentezlenmiştir. Yapılan çalışmada, kumarin iskeletinin 3. pozisyonunda fenil ve p-nitrofenil grubu içeren 6,7-dihidroksikumarin türevleri sentezlenmiştir. Bu bileşiklerden yola çıkılarak 12-taç-4, 15-taç-5 ve 18-taç-6 türevleri hazırlanmıştır. Kumarin-taç eterleri, aşağıdaki metod ile sentezlenmiştir: Polietilenglikolditosilat ve 6,7-dihidroksi-3-fenilkumarin, CH3CN / K2CO3 / H2O varlığında çözülmüştür. Bu karışım; geri soğutucu altında mekanik karıştırıcı ile karıştırılarak 65-75C'de 35-40 saat ısıtıldıktan sonra, karışımın çözücüsü uzaklaştırılmıştır. Saflaştırma işlemi ise, silika jel kolon kromatografisinde yapılmıştır. Yapıları IR, 1H-NMR ve UV/ VIS spektrumları ile karakterize edilmiştir.
Coumarins are natural compounds and they occur in several families of higher plants in the free state or as glucosides. Several o-dihydroxycoumarins are structurally related to the derivatives of cinnamic acid being formed by lactonization. o-dihydroxycoumarins posses potential biological activities. Moreover, some derivatives of o-dihydroxycoumarin are necessary compounds for the synthesis of coumarin-crown ether derivatives. In this study, we synthesized 6,7-dihydroxy-3-phenylcoumarins and 6,7-dihydroxy-3-(4-nitrophenyl)-coumarins. We also prepared 12-crown-4, 15-crown-5 and 18-crown-6 derivatives of o-dihydroxy-3-phenylcoumarins. In the synthesis of all coumarin-crown compounds, the same method has been followed. Accordingly; polyethylenglycolditosylate, o-dihydroxy-3-phenylcoumarin are dissolved thoroughly in CH3CN / H2O / K2CO3 systems. The mixture is heated and stirred mechanically under reflux for 35-40 hours at 65-75C. The solvent is removed. The purification is performed by using silica gel column chromatography. Finally, the structures of crown compounds are determined based on the results of spectroscopic methods such as 1H-NMR, IR and UV/ VIS.
Coumarins are natural compounds and they occur in several families of higher plants in the free state or as glucosides. Several o-dihydroxycoumarins are structurally related to the derivatives of cinnamic acid being formed by lactonization. o-dihydroxycoumarins posses potential biological activities. Moreover, some derivatives of o-dihydroxycoumarin are necessary compounds for the synthesis of coumarin-crown ether derivatives. In this study, we synthesized 6,7-dihydroxy-3-phenylcoumarins and 6,7-dihydroxy-3-(4-nitrophenyl)-coumarins. We also prepared 12-crown-4, 15-crown-5 and 18-crown-6 derivatives of o-dihydroxy-3-phenylcoumarins. In the synthesis of all coumarin-crown compounds, the same method has been followed. Accordingly; polyethylenglycolditosylate, o-dihydroxy-3-phenylcoumarin are dissolved thoroughly in CH3CN / H2O / K2CO3 systems. The mixture is heated and stirred mechanically under reflux for 35-40 hours at 65-75C. The solvent is removed. The purification is performed by using silica gel column chromatography. Finally, the structures of crown compounds are determined based on the results of spectroscopic methods such as 1H-NMR, IR and UV/ VIS.