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.     

Preparation of a New Series,the 3-Ureidomethylenecoumarins by Condensation of 4-Hydroxycoumarin with Substituted Ureas

We report the synthesis in high yield of a series of 3-ureido-methylenecoumarins by condensation of substituted ureas with 4-hydroxycoumarin in the presence of ethyl orthoformate.     

Friedel–Crafts alkylation of 4-hydroxycoumarin catalyzed by sulfonic-acid-functionalized pyridinium chloride as a new ionic liquid

A green, simple and efficient synthesis of bis-coumarin derivatives via the condensation of 4-hydroxycoumarin with arylaldehydes using sulfonic-acid-functionalized pyridinium chloride {[Pyridine–SO₃H]Cl} as a new, homogeneous and reusable catalyst and ionic liquid is reported.     

Catalyst-free one-pot synthesis of a new class of 2H-furo[3,2-c]chromene-2,4(3H)-dione and arylamino-bis(coumarin)methane derivatives on water

A catalyst-free, environmentally benign, and simple procedure has been developed for the efficient synthesis of novel 2H-furo[3,2-c]chromene-2,4(3H)-dione and 3,3′-((arylamino)methylene)bis(4-hydroxycoumarin) derivatives from one-pot three-component condensation of 4-hydroxycoumarin, glyoxalic acid monohydrate and various amines in water under reflux condition. In this green synthetic protocol, the solvent water itself catalyzed the reaction via hydrogen bonding. One-pot, high yields, short reaction times, simple operation, environmental friendly and easy workup procedure are highlights. This is the first report for the synthesis of 2H-furo[3,2-c]chromene-2,4(3H)-dione and arylamino-bis(coumarin)methane derivatives.     

Aflatoxin analogues as possible anticoagulants. III

The synthesis of a series of derivatives of 4-hydroxycoumarin analogues of aflatoxin and a preliminary testing of their anticoagulant activity is described.     

Multicomponent One-pot Diastereoselective Synthesis ofBiologically Important Scaffold under Microwaves

A simple and fast three-component diastereoselective synthesis of biologically important spiro scaffold 4 wascarried out in reasonable purity starting from readily available 1H-indole-2,3-dione 1,ethyl cyanoacetate 2 and4-hydroxycoumarin 3 under microwave in high yield(88%-92%)and short time.     

New method of synthesis of 1,5-benzodiazepin-2-ones from 4-hydroxycoumarin

A new method of synthesis of 1,5-benzodiazepine-2-ones, from 4-hydroxycoumarin and substituted 1,2-phenylenediamines by heating in xylene or acetic acid-ethanol, is reported.     

Efficient Synthesis of Bis-Coumarins Using Silica-Supported Preyssler Nanoparticles

Reaction of aldehydes and 4-hydroxycoumarin in the presence of catalytic amount of silica-supported Preyssler nanoparticles led to synthesis of bis-coumarins in excellent yields.     

Analogs of 3-(1-phenyl-3-oxobutyl)-4-hydroxycoumarin (warfarin) prepared from substituted salicylic acids

Some derivatives of salicylic acid containing substituents meta to the carboxyl group were used to prepare analogs of the anticoagulant drug warfarin, 3-(1-phenyl-3-oxobutyl)-4-hydroxycoumarin, containing substituents in either the 6-or 8-position of the courmarin ring. When the substituent was the hydroxyl group, the resulting products are previously identified metabolites of warfarin. The substituted salicylic acid is first acetylated with acetic anhydride, then either converted to the acid chloride and condensed with diethyl malonate in the presence of sodium hydroxide or converted to the mixed anhydride with formic acid and condensed with ethoxymagnesium diethyl malonate to yield, in either case, the corresponding 3-carbethoxy-4-hydroxycoumarin substituted in the 6- or 8-position of the coumarin ring. These compounds readily condense with benzalacetone to form the corresponding substituted warfarin in the presence of 5 mole % tertiary amine catalyst. This method offers an improved route for the synthesis of 8-hydroxywarfarin.     

An efficient synthesis of novel chromeno[3’, 4’：5, 6]pyrano[2, 3-b]indole derivatives

An efficient two-step method was described for the synthesis of chromeno[3',4':5,6]pyrano[2,3-b]indole derivatives. The three-component reaction of 4-hydroxycoumarin, variously substituted benzaldehydes and indolin-2-one was promoted by P2O5 in refluxing ethanol to give trimolecular adducts, which were then cyclized in 1,2-dichloroethane under reflux using POCl3.     

Cu(II)-β-cyclodextrin-catalyzed synthesis of spiro[indoline-3,4′-pyrano[3,2-c]chromene]-3′-carbonitrile derivatives

Cu(II)-β-cyclodextrin-catalyzed synthesis of spiro[indoline-3,4′-pyrano[3,2-c]chromene]-3′-carbonitriles through the reaction of isatin derivatives, 4-hydroxycoumarin, and malononitrile in ethanol at room temperature.     

Naturstoffchemie. 108. Mitt. Synthese des 7,7′-Oxy-dicumarins,dem möglichen Präkursor vom Lasioerin und Gnidicumarin

The synthesis of 7,7′-oxy-dicoumarin from 7-hydroxycoumarin and 7-bromocoumarin viaUllmann synthesis is described. In contrast to the literature, from the reaction ofm-bromophenol with 2-hydroxy succinic acid, 7-bromocoumarin as well as 5-bromocoumarin were obtained.     

Simple and Cost Effective Syntheses of 4-Hydroxycoumarin

Two simple and inexpensive methods for the preparation of 4-hydroxycoumarin from aspirin are described, which should be readily amenable to large scale synthesis.     

Hydrazones derived from thiooxamohydrazides and 3-formyl-4-hydroxycoumarin: synthesis, structures, and fragmentation

Novel hydrazones were obtained from thiooxamohydrazides and 3-3-formyl-4-hydroxycoumarin. According to data from NMR spectroscopy and X-ray diffraction, the coumarin fragment in the compounds obtained exists as 4-hydroxycoumarin or chromane-2,4-dione. When dissolved in dimethyl sulfoxide, these hydrazones undergo fragmentation into derivatives of 1,3,4-thiadiazole and 4-hydroxycoumarin.     

5,6,7,8-Tetrafluoro-4-hydroxycoumarin derivatives in reactions with o-phenylenediamine

The reactions of 5,6,7,8-tetrafluoro-4-hydroxycoumarin derivatives with o-phenylenediamine occur with pyrone heterocycle cleavage and formation of substituted benzodiazepin-2-ones. 5,6,7,8-Tetrafluoro-4-hydroxycoumarin affords 4-(3,4,5,6-tetrafluoro-2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepin-2-one, 3-acetimidoyl-5,6,7,8-tetrafluoro-4-hydroxycoumarin produces 3-(3,4,5,6-tetrafluoro-2-hydroxybenzoyl)-4-methyl-1,2-dihydro-1H-1,5-benzodiazepin-2-one, and 3-acetyl-5,6,7,8-tetrafluoro-4-hydroxycoumarin yields both these heterocycles.     

Catalyst-free synthesis of 3-hydroxyimidazo[1,2-a]pyridine zwitterion derivatives via the three-component reaction of ethyl glyoxalate, 2‑aminopyridines and cyclic 1,3-dicarbonyls

The three-component reaction of ethyl glyoxalate, 2-aminopyridines, and cyclic 1,3-dicarbonyl compounds such as 4-hydroxycoumarin, N,N-dimethylbarbituric acid and 4-hydroxy-6-methyl-2H-pyran-2-one is described for the synthesis of 3-hydroxyimidazo[1,2-a]pyridine zwitterion derivatives.     

[2,2'-Bipyridine]-1,1'-diium perchlorate as a new and efficient dicationic organic salt for the promotion of the synthesis of bis(4-hydroxycoumarin), 5-arylidene barbituric acid and pyrano[2,3-d]pyrimidinone derivatives in water

Research on Chemical Intermediates - A simple and convenient procedure for the synthesis of 5-arylidene barbituric acid, pyrano[2,3-d]pyrimidinone and 4-hydroxycoumarin derivatives using...     

A convergent paired electrochemical synthesis of new heterocyclic compounds. Reaction of benzoquinones with 3-Amino-4-hydroxycoumarin

Electrochemical oxidation of catechols (1) has been studied in the presence of cathodically generated 3-amino-4-hydroxycoumarin (3a) as a nucleophile in aqueous solutions, using cyclic voltammetry and controlled-potential coulometry. The results indicate that the o-benzoquinones derived from catechols (1) participate in Michael addition reaction with 3-amino-4-hydroxycoumarin (3a) to form the corresponding new heterocyclic compounds (7) (oxidized form of coumestan derivatives). The electrochemical process consists of a multi-step including (a) cathodic reduction of 4-hydroxy-3-nitrocoumarin (3) to 3-amino-4-hydroxycoumarin (3a), (b) anodic oxidation of catechols (1) to related o-benzoquinone (2), (c) the Michael addition reaction of 3-amino-4-hydroxycoumarin (3a) to o-benzoquinone (2), and (d) anodic oxidation of formed adduct. The paired electrochemical synthesis of compounds 7a and 7b has been successfully performed in a one-pot process at carbon rods as working and counter electrodes in an undivided cell.     

One-pot chemoselective synthesis of novel fused pyrimidine derivatives

One-pot triple-component reaction of 4-hydroxycoumarin with aromatic aldehydes and 2-aminobenzimidazole, 3-amino-1H-1,2,4-triazole, or 6-aminouracil in acetonitrile in the presence of catalytic amounts of sulfamic acid led to a chemoselective synthesis of chromeno[4,3-d]pyrimidine-6-one, triazolo[1,5-a]pyrimidin-5-one, and pyrido[2,3-d]-pyrimidine-2,4,7-trione derivatives, respectively, in good yields.     

One-pot synthesis of dihydropyrano[2,3-c]chromenes via a three component coupling of aromatic aldehydes, malononitrile, and 3-hydroxycoumarin catalyzed by nano-structured ZnO in water: a green protocol

An efficient and green protocol for the synthesis of dihydropyrano[2,3-c]chromene derivatives by one-pot, three component coupling reaction of aromatic aldehyde, malononitrile, and 3-hydroxycoumarin has been developed using nano-structured ZnO as the catalyst. The formation of self-assembled organic nanofiber arising from low-molecular-weight molecules has also been performed. The optical properties of the nano-structured organic molecules were studied.