Reaction Of 4-hydroxycoumarin Research Articles

Green Synthesis of 4-aryl-3,4-Dihydrochromeno[3,4-e][1,3]Oxazine-2,5-Dione in Aqueous Media by Condensation of 4-Hydroxycoumarin with Aromatic Aldehydes and Methyl Carbamate

A green and efficient synthesis of the title compounds has been achieved in a one-pot, three-component reaction of 4-hydroxycoumarin and aromatic aldehydes with methyl carbamate catalysed by p-toluenesulfonic acid in aqueous media to afford 4-aryl-3,4-dihydrochromeno[3,4-e][1,3]oxazine-2,5-diones in excellent yields. The salient features of this protocol are: short reaction times, high yields and absence of any hazardous organic solvent. Consequently, this procedure could be classified as green chemistry.

Reaction of 4-hydroxycoumarin or its O-substituted derivatives with diatomic interhalogens: ICl and IBr

ABSTRACTHerein, we present some aspects regarding the iodination/bromination of 4-hydroxycoumarin or its O-methyl or O-acetyl derivatives with iodine monochloride or iodine monobromide as halogenation reagents. Also, the investigation of photochemical transformation of the three 3-iodocoumarins was investigated for the first time.

Microwave-assisted synthesis and antifungal activity of novel fused Osthole derivatives

Based on the microwave-assisted synthetic protocol developed in our previous work, we have synthesized a series of novel furo[3,2-c]coumarins as fused Osthole derivatives, via the reaction of 4-hydroxycoumarins and β-ketoesters catalyzed by DMAP. All the target compounds were evaluated in vitro for their antifungal activity against six phytopathogenic fungi, some compounds exhibited potential activity in the primary assays. Especially compounds 6c, 7b, 8b and 8c (shown in Fig. 1) were the most active ones, EC50 values of these four compounds against Colletotrichum capsica, Botrytis cinerea and Rhizoctonia solani were further investigated. 6c was identified as the most promising candidate with the EC50 value at 0.110 μM against Botrytis cinerea and 0.040 μM against Colletotrichum capsica, respectively, representing better antifungal activity than that of the commonly used fungicide Azoxystrobin.

Silane@TiO 2 nanoparticles-driven expeditious synthesis of biologically active benzo[4,5]imidazo[1,2-a]chromeno[4,3-d]pyrimidin-6-one scaffolds: A green approach

A simple, efficient and environmentally benign protocol has been developed for the synthesis of substituted benzo[4,5]imidazo[1,2-a]chromeno[4,3-d]pyrimidin-6-one by a reaction of 4-hydroxycoumarin, aldehydes and 2-aminobenzimidazole using silane@TiO2 nanoparticles as heterogeneous catalyst under reflux condition in ethanol. The surface modification of TiO2 nanoparticles was confirmed by using FT-IR, FE-SEM, EDX, XRD and TEM analyses. Furthermore, the stability of the catalyst was evaluated by thermal gravimetric analysis (TGA). Some advantages of this method are high yield of products, short reaction time; recyclability of the catalyst and column chromatography-free protocol. The synthesized compounds were screened for their in vitro antioxidant activity and most of the compounds exhibited remarkable antioxidant activity. A simple, efficient and environmentally friendly synthesis of substituted benzo[4,5]-imidazo-[1,2-a]-chromeno-[4,3-d]-pyrimidin-6-one is described using silane@TiO2 nanoparticles as heterogeneous catalyst under reflux conditions in ethanol.

Catalytic performance of a Keplerate-type, giant-ball nanoporous isopolyoxomolybdate as a highly efficient recyclable catalyst for the synthesis of biscoumarins

AbstractIn continuation of our previous works on the application of (NH4)42[MoVI72MoV60O372(CH3COO)30(H2O)72], a Keplerate-type giant-ball nanoporous isopolyoxomolybdate, as a catalyst for a series of organic transformations, in this paper, we discovered that this new attractive catalyst has high catalytic activity in the synthesis of biscoumarins prepared by the reaction of 4-hydroxycoumarin and aromatic or aliphatic aldehydes in refluxing ethanol. The catalyst was prepared according to a previously published literature procedure using inexpensive and readily available starting materials. Furthermore, the catalyst could be recovered conveniently and reused efficiently such that a considerable catalytic activity still could be achieved after fifth run. Other beneficial features of this new synthetic approach include short reaction time, high yields, clean reaction profiles, and a simple work-up procedure.

Brønsted Acidic Phosphonium Based Ionic Liquid Functionalized SBA-15 [HO3S-PhospIL@SBA-15]: Green, Recyclable, and Efficient Catalyst for the Synthesis of Pyrano[3,2-c]Chromenone Derivatives

The surface of SBA-15 was modified by diphenylphosphine; then, it was treated with butane sultone and sulfuric acid to obtain Bronsted acid HO3S-phosphonium based ionic liquid functionalized SBA-15 with HSO4 - as a counteranion. It efficiently catalyzed synthesis of pyrano(3,2-c)chromenone derivatives through the reaction of 4-hydroxycoumarin and chalcones at 60 °C in water/ethanol. Good yields, mild reaction conditions, and user-friendly procedure are advantages of this method. Also, the catalyst could be easily separated and reused five times without significant reduction of activity.

Green approach to stereoselective synthesis of benzo[d]chromeno[3,4- h]oxathiazonine derivatives via MCRs in water: a combined experimental and DFT study.

(7S, 14S, 16R)- dialkyl 6-oxo-6,7,13,14-tetrahydro-7,14-methanobenzo[d]chromeno[3,4- h][1,6,3]oxathiazo-nine-14,16-dicarboxylates 4 and (S)-methyl 2-(2-methoxy-2-oxoethyl)-2,3- dihydrobenzo[d]thiazole-2-carboxylates 5 were readily synthesized in a ratio 3:1 and moderated yield by multicomponent reactions of 4-hydroxycoumarin and acetylenic esters with benzothiazole without using a catalyst. Also, The GIAO/DFT approach at the B3LYP/6-31G** level of theory was used to calculate the (1)H, (15)N, (17)O and (13)C NMR chemical shifts of product 4b. These computations are performed on the basis of X-ray structural data which are collected at 120(2) K temperature. In order to take into account intermolecular hydrogen bonds and the van der Waals effects, two different sizes of clusters (two model of trimeric and pentameric clusters) have been considered. A comparison between the experimental (Exp.) and calculated (Cal.) (1)H and (13)C NMR chemical shifts may reveal that the solution contains monomer, trimer1, trimer2, and pentamer models.

Novel macromolecules derived from coumarin: synthesis and antioxidant activity.

The rational design of 4-hydroxycoumarins with tailor-made antioxidant activities is required nowadays due to the wide variety of pharmacologically significant, structurally interesting of coumarins and researcher orientation toward green chemistry and natural products. A simple and unique coumarins have been achieved by reaction of 4-hydroxycoumarin with aromatic aldehyde accompanied with the creation of a macromolecules have 2-aminothiazolidin-4-one. The molecular structures of the compounds were characterized by the Fourier transformation infrared and Nuclear magnetic resonance spectroscopies, in addition to CHN analysis. The scavenging abilities of new compounds against stable DPPH radical (DPPH•) and hydrogen peroxide were done and the results show that the compounds exhibited high antioxidant activates.

Synthesis of Functionalized Dihydrofurocoumarin Derivatives from 3-Aminoalkyl-4-hydroxycoumarin

Some dihydrofuro-fused coumarin derivatives were synthesized from 3-aminoalkyl-4-hydroxycoumarin via in situ generation of N-ylide. The 3-aminoalkylated 4-hydroxycoumarin derivatives were synthesized from one-pot, three-component reaction of 4-hydroxycoumarin, aryl aldehydes, and secondary amines in ethanol at room temperature. Again, when salicylaldehyde was employed instead of benzaldehyde, interestingly pyranocoumarins were obtained. The reaction protocol can be further explored toward the synthesis of many other heterocyclic fused dihydrofurans.

A facile and practical p-Toluenesulfonic acid catalyzed route to dicoumarols containing an Aroyl group

New and known dicoumarols may be efficiently synthesized employing p-toluenesulfonic acid (p-TSA) as a solid acid catalyst from the reaction of 4-hydroxycoumarin with aryl glyoxal in water. This method offers direct access to structurally diverse coumarin derivatives in moderate to good yields (up to 65%). A total of five new compounds were synthesized.

Tungstate sulfuric acid catalyzed one-pot synthesis of a new class of aroylamido coumarins under solvent-free conditions

A one-pot synthesis of novel aroylamido coumarins from the reaction of 4-hydroxycoumarin with aryl glyoxals and benzamides in the presence of a catalytic amount of tungstate sulfuric acid (TSA) is described. The method is operationally simple and provides access to a variety of aroylamido coumarins in good yields.

Solvent-free and One-pot Synthesis of Trisubstituted Methanes Containing Coumarin Catalysed by Yttrium(III) Nitrate

A one-pot method has been developed for the synthesis of novel trisubstituted methanes containing coumarin by the reaction of 4-hydroxycoumarin with aryl glyoxal and benzamide under solvent-free conditions. The reactions were efficiently catalysed by yttrium(III) nitrate to afford corresponding products in moderate to good yields. The synthetic procedure is simple, inexpensive and environmentally friendly.

Synthesis of New and Known Dicoumarols in Aqueous Media: A Green and Convenient Procedure Promoted by Titanium(IV) Oxide Nanoparticles

A simple and green method is reported for the completely chemoselective synthesis of some new dicoumarol derivatives {3,3'-(2-aryl-2-oxoethylidene)bis[4-hydroxycoumarin]s} from the reaction of 4-hydroxycoumarin with arylglyoxals in a molar ratio of 2:1 respectively. The reactions efficiently promoted by titanium(IV) oxide nanoparticles as a heterogeneous catalyst via an on water process. Catalyst loading is very low and it shows recyclability. Keywords: Titanium(IV) oxide nanoparticles, chemoselectivity, 3, 3'-(2-aryl-2-oxoethylidene)bis[4-hydroxycoumarin]s, catalysts, arylglyoxal.

Synthesis of Aroyl[bis(4-Hydroxycoumarin-3-yl)]Methane Using Tungstate Sulfuric Acid in Water

An efficient synthesis of some new aroyl[bis(4-hydroxycoumarin-3-yl)]methanes (dicoumarols) based on the reaction of 4-hydroxycoumarin with arylglyoxals is described. The reactions were efficiently catalysed by tungstate sulfuric acid to afford the product in moderate to good yields (up to 65%).

PEG Mediated Eco-Friendly One Pot Sunthesis of Benzylamine Coumarin Derivatives Using Multicomponent Reactant

A green resourceful, eco-friendly and facile protocol was developed for the synthesis of benzylamine coumarin derivatives by the reaction of 4-hydroxy coumarin, secondary amine and aromatic aldehyde in the presence of PEG400 as a solvent as well as catalyst at room temperature. A wide range of functional groups were tolerated in the developed protocol. The structures of all the synthesized compounds were confirmed by 1H NMR, IR, MASS and Elemental Analysis. The target molecules were obtained in good to excellent yield applying this method.

PEG Mediated Eco-Friendly One Pot Sunthesis of Benzylamine Coumarin Derivatives Using Multicomponent Reactant

A green resourceful, eco-friendly and facile protocol was developed for the synthesis of benzylamine coumarin derivatives by the reaction of 4-hydroxy coumarin, secondary amine and aromatic aldehyde in the presence of PEG400 as a solvent as well as catalyst at room temperature. A wide range of functional groups were tolerated in the developed protocol. The structures of all the synthesized compounds were confirmed by 1H NMR, IR, MASS and Elemental Analysis. The target molecules were obtained in good to excellent yield applying this method.

Synthesis of biscoumarin derivatives using poly(4-vinylpyridine)-supported dual acidic ionic liquid as a heterogeneous catalyst

A supported dual acidic ionic liquid catalyst was easily prepared from its starting materials (namely poly(4-vinylpyridine) and 1,4-butanesultone) and used as a highly efficient heterogeneous catalytic system for the synthesis of biscoumarin derivatives from the reaction of 4-hydroxycoumarin with aliphatic and aromatic aldehydes. The catalyst can be easily recovered and reused without appreciable change in its efficiency.

One-pot Synthesis of Novel Pyrano-Fused Coumarins Catalyzed by ZnO Nanoparticles

A new class of pyrano[3,2-c]coumarins containing an aryloylgroup was synthesized via the three-component reactions of 4-hydroxycoumarin with arylglyoxals and malononitrile. The reactions are efficiently catalyzed by zinc oxide nanoparticles as powerful and recyclable catalyst. The green chemistry principles were also considered and the present method has some advantages, such as simplicity, low catalyst loading, and high yields. From the perspective of environmental problems, the avoidance of harmful organic solvents is one of the efficient ways to decrease the concerns in chemical research and industry. In regard of the fundamental principles of the green chemistry, the elimination of toxic solvents and the generation of waste are important items. In chemical reactions, transition metal oxides are commonly used due to their catalytic activity. Among the nano-sized transition metal oxides, zinc oxide nanoparticles (ZnO NPs) have gained tremendous importance as they exhibit interesting catalytic properties which cannot be achieved by their bulk counterparts. ZnO nanomaterials are non-toxic and water-insoluble material which can be recovered and reused, therefore, it can help to reduce the waste. The pyranocoumarins possess several types of pharmacological properties, such as anti-HIV, antibacterial, insecticidal, anticancer, and anti-inflammatory activities, thus, they have received considerable attention. Among pyranocoumarins, the pyrano[3,2-c]coumarins are the most synthetically feasible. Generally, pyrano[3,2-c]coumarins are affordable from commercially available 4-hydroxycoumarin with 1670 HETEROCYCLES, Vol. 89, No. 7, 2014

Synthesis of 4-hydroxy-3-[(E)-2-(6-substituted-9H-purin-9-yl)vinyl]coumarins as lipoxygenase inhibitors

The synthesis of 4-hydroxy-3-[(E)-2-(6-substituted-9H-purin-9-yl)vinyl] coumarins has been achieved from the reactions of 4-hydroxycoumarin with 2-(6-substituted-9H-purin-9-yl)acetaldehydes in DMF under heating. The new compounds showed significant lipoxygenase inhibitory activity (e.g., 6a: IC50=6.25μM).

Boric Acid–Catalyzed One-Pot Access to 7-Aryl-benzopyrano[4,3-b] benzopyran-6,8-diones Under Aqueous Micellar Conditions

A mild protocol for the synthesis of 7-arylbenzopyrano[4,3-b]benzopyran-6,8-diones by three-component reaction of 4-hydroxycoumarin, aromatic aldehyde, and 5,5-dimethylcyclohexane-1,3-dione (dimedone) with boric acid catalyst under aqueous micellar conditions is described. Good to excellent yield, high selectivity, tolerance of several common functional and protecting groups, and green features including avoidance of organic solvent in the reaction as well as isolation stage and use of nontoxic water-compatible mild Lewis acid catalyst are key attractive features of the protocol. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]