7-羟基香豆素类及其烯基醚衍生物的合成

以间苯二酚、乙酰乙酸乙酯和1,3-丙酮二羧酸为原料,经Pechmann反应和Knoevenagel反应合成了4个7-羟基香豆素类化合物——7-羟基-4-甲基香豆素(1),7-羟基-4-乙酸甲酯香豆素-(2),7-羟基-3-甲酸乙酯香豆素(5)和7-羟基-3-乙酰基香豆素(6)。以四丁基溴化铵为相转移催化剂,1,2,5和6分别经O-异戊烯基化或O-法尼烯基化反应合成了6个7-羟基香豆素类的烯基醚衍生物,其中5个为新化合物,其结构经1H NMR,IR和MS表征。     

Solvent Free Synthesis of Coumarins

An efficient synthesis of 3-substituted coumarins under solventless system is described.     

Synthesis and Characterization of New Helical Coumarins

The phenomenon of peri interaction of 1,8‐disubstituted naphthalene has been utilized to construct small molecules with internal twist resulting in helical isomers. A series of new naphthalene‐attached coumarins have been synthesized and characterized. The helical conformational twist in thiophene–coumarin capped naphthalene was established by H‐NMR and single crystal X‐ray diffraction analysis.     

New Synthesis of 3-Alkyl Coumarins

3-Alkyl coumarins are reported to have anthelmintic, hypnotic and insecticidal properties^1–3. Here we report a novel general method for the synthesis of 3-alkylated coumarins. This involves direct C-alkylatioa at the C-3 position of 3-carbethoxy-3,4-dihydrocoumarin followed by hydrolysis, decarboxylation and dehydrogenation of the resulting dihydrocoumarin. 3-Methyl-, 3-ethyl-, 3-n-pro-pyl-, and 3-benzylcoumarins have been synthesised in good yields following the same procedure depicted in the Scheme-1.     

Synthesis and Antimicrobial Activities of Some Triazole,Thiadiazole, and Oxadiazole Substituted Coumarins

Ethyl‐2‐(4‐methyl‐2‐oxo‐2‐coumarin‐7‐yloxy)acetate 1 has been prepared from 7‐hydroxy‐4‐methyl‐2‐coumarin, which on further treatment with hydrazine hydrate in boiling ethanol gave the hydrazide compound 2 . The resulting hydrazide was reacted with substituted aryl isothiocyanates to form thiosemicarbazides compounds 3a , 3b , 3c , 3d , 3e . 1‐(2‐(4‐Methyl‐2‐oxo‐2‐coumarin‐7‐yloxy)acetyl)‐4‐aryl thiosemicarbazides 3 underwent cyclization with different reagents under different reaction conditions to furnish coumarin derivatives possessing triazoles 4a , 4b , 4c , 4d , 4e , thiadiazoles 5a , 5b , 5c , 5d , 5e , and oxadiazoles 6a , 6b , 6c , 6d , 6e , respectively. The structures of all the compounds have been assigned by elemental analysis and spectral studies. The synthesized compounds were screened for their antimicrobial analgesic activities. The nonconventional controlled microwave irradiation synthesis is carried out at (200 W) at 70°C. This approach offers a number of advantages in terms of methodology, high‐product yield, short reaction time, mild reaction conditions, environmentally benign, and easy workup.     

新型香豆素类荧光化合物的合成及荧光性质研究

合成了两种香豆素类荧光化合物6,8-二氯-7-羟基香豆素-3-羧酸（DClC）和6-氯-7-羟基香豆素-3-羧酸（MClC）,其中DClC未见文献报道,并通过红外光谱、核磁共振、质谱等手段对产物的结构进行了表征。同时首次研究了这两种香豆素衍生物的紫外、荧光性质,以及不同极性溶剂、pH值、表面活性剂等的影响。结果表明,pH对性质测定影响较大,当pH=10时,DClC和MClC的荧光强度明显增强。     

Plant Coumarins: XVII. Synthesis and Transformations of 7-Hydroxy-2-oxo-2H-chromene-6-carboxamides

Russian Journal of Organic Chemistry - Umbelliferone-6-carbonyl chloride reacted with amines and α-, β-, and ω-amino acid methyl esters to afford the corresponding N-substituted...     

氯化硅胶催化下无溶剂合成香豆素类化合物

以氯化硅胶为催化剂,应用β-酮酸酯对各种酚进行Pechmann反应,在80℃和无溶剂的条件下,合成了一系列香豆素类化合物.该方法具有反应条件温和,产率高(67%～96%)和操作简单等优点.产物结构经IR,1H NMR,元素分析等进行了表征.     

Modified Coumarins. I. Synthesis of 5-Phenyl-7H-furo[2, 3-g]chromen-7-ones and 9-Phenyl-7H-furo-[2, 3-f]chromen-7-ones

5-Phenyl-7H-furo[2,3-g]chromen-7-ones and 9-phenyl-7H-furo-[2,3-f]chromen-7-ones, new analogs of psoralen and allopsoralen, are synthesized from 7-hydroxy- and 5-hydroxy-4-phenylcoumarins     

Efficient Synthesis of 3‐Substituted Coumarins

Abstract

The Mukaiyama's esterification protocol, using 2‐chloro‐1‐methylpyridinium iodide‐triethylamine reagent, has been successfully exploited to provide rapid access to a variety of 3‐substituted coumarins in satisfactory yields.     

钯催化合成香豆素研究进展

香豆素是一类苯并六元含氧杂环类化合物,具有抗氧化、抗菌、抗炎等多种生理活性,受到人们的广泛关注。近年来不断有香豆素的新合成方法报道,特别是高效的过渡金属钯催化合成反应。本文综述了近20年来钯络合物催化合成香豆素骨架的研究进展,主要包括羰基化反应、炔烃芳基化反应、烯烃芳基化反应和偶联反应,以期为合成新型香豆素提供参考。     

The Synthesis and Biological Evaluation of Regioisomeric Benzothiazolyl Coumarins

Various 4-aryloxymethylcoumarins have been obtained by the r.t. allylic substitution with formylphenols. These have been further reacted with o-aminothiophenol resulting in the formation of a benzothiazole skeleton. These compounds have been synthesised with a view to study their potential as microbial growth inhibitors. Comparative studies on the spectral and antimicrobial activities have also been carried out.     

The Synthesis of a Series of Phosphoryl Coumarins

Different hydroxy substituted coumarins were successfully phosphorylated with diisopropylphophite （DIPPH） by the Atherton-Todd reaction in 76-89% yields. Moreover, the reaction activities of different hydroxys of the coumarins in the Atherton-Todd reaction were studied.     

Synthesis of Two Coumarins Isolated from Aster praealtus

Two coumarins isolated from Aster praealtus were synthesized via a direct coupling of the corresponding cyclohexyl carbinol with a coumarin‐derived aryl bromide or iodide, a very difficult etherification due to the excess steric congestion around the carbinol and the low reactivity of the aryl halide that frustrated many seemingly feasible protocols. Unequivocal ¹H and ¹³C NMR data for these compounds were thus made available for the first time. Uncertainty and errors in ¹H and ¹³C NMR data in previous reports are also eliminated and revealed, respectively.     

A Route to the Synthesis of Novel Coumarins

Summary. The 1:1:1 adduct which originates from the reaction of triphenylphosphine, dialkyl acetylenedicarboxylate, and 3-formyl-4-hydroxycoumarin undergoes an intramolecular Wittig reaction to provide a series of unique 2H,5H-pyrano[3,2-c][1]benzopyran-5-ones (pyranocoumarins).     

A One-Pot and Convenient Synthesis of Coumarins in Solventless System

An efficient and facile preparation of simple coumarins via in situ Wittig reaction of salicylaldehydes, triphenylphosphine, and chloroethylacetate supported on MgO in satisfactory yields in solvent-free condition.     

Synthesis,Cytotoxic Evaluation,and In Silico Studies of 4‐Substituted Coumarins

Two series of coumarins possessing the aniline‐ and heterocyclic ring at 4^th position have been synthesized and evaluated for their in vitro cytotoxic activity against MCF‐7 cancer cell line in MTT assay. Structure activity relationship (SAR) studies reveal that the electron donor group at position‐8 of coumarin played an important role in cytotoxic activity. Compound VIId showed the potent cytotoxic activity followed by compound Xa with IC₅₀ = 6.25 and 6.50 μM, respectively. A docking study has also been carried out for the most potent compound to get an insight into molecular interactions with p50 subunit of NF‐κB protein.