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Potassium phthalimide-N-oxyl: a novel, efficient, and ...

Jan 21, 2013· A wide variety of 2-amino-4H-chromene derivatives with diverse substituents on the 4H-chromene ring were efficiently prepared via one-pot, three-component reaction of an aromatic aldehyde, malononitrile (or ethyl cyanoacetate), and diverse enolizable C–H activated acidic compounds in the presence of low loading of potassium phthalimide-N-oxyl (POPINO), as a new organocatalyst, in …

Methods of synthesis of chromeno[2,3-b]chromenes ...

Jun 04, 2021· Thermolysis of 2-[(dimethylamino)methyl]phenols by heating in DMF under reflux in the presence of malononitrile and DBU with the reagent ratio of 2:1:1 leads to the formation of 5а-amino-5аН,11Н-chromeno[2,3-b]chromene-11а(12H)-carbonitriles 6 in 37–49% yields. 8a It is a cascade reaction and includes the following main steps: thermal generation of o-quinone methide A from the …

Synthesis of (±)‐cis‐1‐Aryl‐3‐oxo‐2,3‐dihydro‐1H‐benzo[f ...

Nov 27, 2019· The unexpected stereospecific synthesis of (±)-cis-1-aryl-3-oxo-2,3-dihydro-1H-benzo[f]chromene-2-carbonitriles (2) and (±)-trans-4-aryl-2-oxo-3,4-dihydro-2H-benzo[h]chromene-3-carbonitriles (4) from (±)-3-amino-1-aryl-1H-benzo[f]chromene-2-carbonitriles (1) and (±)-2-amino-4-aryl-4H-benzo[h]chromene-3-carbonitriles (3), respectively, by ...

One-pot solvent-free rapid and green synthesis of 3,4 ...

Abstract An easy solvent-free method is described for the synthesis of 3,4-dihydropyrano[c]chromenes by a one pot three component coupling reaction of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin using basic ionic liquid as the catalyst by grindstone chemistry. The salient features of this one pot protocol are short reaction times, cleaner reaction profiles and simple workup.

A facile and efficient synthesis of new pyrimido[4',5':4,5 ...

Sep 12, 2015· amino-1H-benzo[f]chromene-2-carbonitrile products in high yields. Table 2: Synthesis of the 3-amino-1H-benzo[f]chromene-2-carbonitriles 4a-i using the DMAP catalyst under the optimized conditions En try Ar Product Time (min) Isolated yield (%) Melting point (ºC) Found Reported [Lit.] 1 C 6 H 5 4a 45 85 287-289 287-288 (Gong et al., 2008) 2 4 ...

Notes. Use of Cation Exchange Resins in Organic Reactions ...

Synthesis of the Coumarins via Pechmann Method in the Presence of Environmentally Friendly Y ... Highly efficient conversion of fused 2-amino-4-aryl-4H-chromene-3-carbonitriles into fused 2-oxo-4-aryl-2H-chromene-3-carbonitriles using Vilsmeier conditions. ... chromen-2-yl methanone and 3H-Benzo[f]chromene-3-one Under Solvent Free Condition.

Solvent-free cascade assembling of salicylaldehydes and ...

Jan 24, 2014· First, to evaluate the synthetic potential of the procedure proposed and to optimize the general conditions, the solvent-free base-initiated cascade transformation of salicylaldehyde 1a and two equivalents of methyl cyanoacetate (2a) into 2-amino-4H-chromene 3a was studied under usual stirring conditions (method A; Table 1).The best yield of 2-amino-4H-chromene 3a (98 %) was achieved …

An efficient, multicomponent approach for solvent-free ...

Method: The reaction of 3-amino-1-(substitutedphenyl)-1H-benzo[f]chromene-2-carbonitrile with sodium azide, ammonium chloride in dimethyl formamide solvent under reflux condition for 4 h afforded ...

Pentafluoropropionic Acid: An Efficient and Metal-Free ...

Apr 23, 2014· Pentafluoropropionic acid (PFPA) efficiently catalyzes the one-pot, three-component reaction of aromatic aldehyde, malononitrile, and dimedone to yield tetrahydrobenzo[b]pyran derivatives in high yields. This method is of great value because of its easy processing, short reaction time, environmentally, and high yields.

DIGITAL.CSIC: The reaction of 2-amino-4 H-pyrans with N ...

The reaction of racemic 2-amino-4H-pyrans, such as 3-amino-1-aryl-1H-benzo[f]chromene-2-carbonitriles, with N-bromosuccinimide (NBS), in CH2 Cl2, at room temperature, is a very quick, regio, stereoselective, and high yielding process, affording major racemic (1S,2S)-2-bromo-3-imino-benzo[f]chromene or racemic (1S,2S)-2-bromo-3-(bromoimino ...

Ball milling for the quantitative and specific solvent ...

Ball milling is used as a facile, efficient, cheap, and environmentally friendly procedure for the solvent-free three-component reaction of aromatic aldehydes with malononitrile and dimedone, or 1,3-cyclohexanedione, resorcinol, and α- and β-naphthol. The reactions …

Ethyl 3-amino-1-phenyl-1H-benzo[f]chromene-2-carboxyl­ate

Apr 01, 2009· Comment . 2-Naphthol, substituted benzaldehydes and ethyl 2-cyanoacetate react in the presence of a catalyst to form the ethyl 3-amino-1-aryl-1H-benzo[f]chromene-2-carboxylates; the compounds possess a primary amine group.The crystal structures of several 1-aryl derivatives have been reported (Klokol et al., 1987; Shi et al., 2003a; Shi et al., 2003b; Wang et al., 2003; Zhuang et al., …

PEG-400 remarkably efficient and recyclable media for one ...

2-Amino-4H-chromenesare generally prepared by refluxing malononitrile, aldehyde, and activated phenol in the presence of hazardous organic bases such as piperidine in organic solutions, such as ethanol and acetonitrile for several hours (4). A literature survey reveals that several methods were reported for the synthesis of 2-amino-4H-chromenes

Synthesis, in-vitro cytotoxicity of 1H-benzo[f]chromene ...

May 01, 2017· A series of 1 H -benzo[ f ]chromene-2-carbonitriles was synthesized and evaluated for their cytotoxic activities against MCF-7, HCT-116, and HepG-2 cancer cells. The SAR studies reported that the substitution in the phenyl ring at 1-position of 1 H -benzo[ f ]chromene nucleus with the specific group, H atom, or methoxy group at 9-position increases the ability of the molecule against the ...

Multicomponent assembling of salicylaldehydes ...

Dec 01, 2015· The solvent-free reaction of salicylaldehyde 1a, malononitrile and 4-hydroxy-6-methyl-2H-pyran-2-one without catalyst in a reaction time of 15 min (entry 1, Table 2) resulted in the formation of 4-pyrano-substituted 2-amino-4H-chromene 2a in only 26% yield. In the presence of 10 mol % of NaOAc as a catalyst, 2-amino-4H-chromene 2a was obtained in 60% yield (entry 2, Table 2).

Convenient and efficient method for synthesis of ...

An eco-friendly and efficient straightforward method has been developed for the synthesis of ethyl 3-amino-1-aryl-1H-benzo[f]chromene-2-carboxylate derivatives via 1,4-diazabicyclo[2.2.2]octane ...

Synthesis of ethyl-3-amino-1-aryl-1H-benzo[f]chromeme-2 ...

substrates. By using this method, different kinds of various aromatic aldehydes compounds were reacted with malononitrile or ethyl cyanoacetate an d phenols to produce the corresponding chromenes derivatives under reflux conditions (Table 2). Table. 2. One-pot synthesis of ethyl-3-amino-1-aryl-1H-benzo[f]chromeme-2-carboxylate

X-ray, Microwave Assisted Synthesis and Spectral Data of 3 ...

A convenient and efficient method using Microwave assisted synthesis of 3-amino-1-(3,5-di-bromo-2-methoxyphenyl-8-methoxy-1H-benzo[f]chromene-2-carbonitrile 5, via reaction of 6-methoxy-2-naphthol 1 with a mixture of 3,5-dibromo-2-methoxybenzaldehyde 2 and malononitrile 3 and also, by the reaction of 6-methoxy-2-naphthol 1 with 2-(3,5-dibromo-2-methoxybenzylidene)-malononitrile 4 in ethanolic ...

One-pot three-component synthesis of 2-Amino-4H-Chromene ...

Jul 01, 2017· An efficient and environmentally benign method has been developed for the synthesis of 2-amino-4H-chromene derivatives via one-pot multi component condensation of resorcinol (1), malononitrile (2), and various aromatic aldehydes (3a–j), using highly monodisperse palladium nanoparticles supported with graphene oxide ([email protected]) as a heterogeneous catalyst.

A Greener Synthesis of 2-Aminochromenes in Ionic Liquid ...

A Greener Synthesis of 2-Aminochromenes in Ionic Liquid and Evaluation of Their Antiproliferative Activities ... An improved simple and facile synthesis of chromene derivatives by employing three- ... Among different types of chromene systems, 2-amino-4H-chromenes are of particular

Solvent-Free Green and Efficient One-Pot Synthesis of ...

Oct 24, 2013· Several methods have been reported for the synthesis of pyrano[3,2-c]chromene derivatives. 2-Amino-4-aryl-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitriles have previously been prepared from aromatic aldehydes, malononitrile, and 4-hydroxycoumarin in the presence of organic bases like piperidine or pyridine in an organic solvent, that is ...

Synthesis and Characterization of a Novel Nanosilica ...

A novel rice-husk-silica supported n-propyl bipyridinium chloride (RHPrBPCl) has been prepared. Due to the basicity of RHPrBPCl, it was decided to evaluate its catalytic activity in the one-pot preparation of tetrahydrobenzo[b]pyran, dihydropyrano[3,2-c]chromene and dihydropyrano[4,3-b]pyran derivatives. The catalyst was characterized by FT-IR, SEM and TGA analyses.

3-Amino-1-(4-fluoro­phen­yl)-8-meth­oxy-1H-benzo[f ...

Apr 01, 2013· The title compound, C 21 H 15 FN 2 O 2, features an approximately planar 1H-benzo[f]chromene fused-ring system (r.m.s. deviation for the 14 non-H atoms = 0.052 Å), with the fluoro­benzene ring being almost perpendicular to this [dihedral angle = 85.30 (7) °].The furan ring has a flattened half-chair conformation, with the methine C atom deviating by 0.132 (2) Å from the plane of …

Convenient and Efficient One-Pot Method for the Synthesis ...

A convenient and efficient one-pot method for the synthesis of 2-amino-tetrahydro-4H-chromene and 2-amino-4H-benzo[h]-chromene derivatives has been developed using a catalytic amount of amino-functionalized MCM-41 in aqueous medium.This efficient technique has the advantages of giving 4H-tetrahydro-chromene and 4H-benzo[h]chromene building blocks using a reusable catalyst in good to …

Pyridylmethylaminoacetic acid functionalized Fe magnetic ...

in the synthesis of chromene and pyran derivatives 1-4 via three-component reaction of enolic or phenolic com-ponent, such as dimedone, -naphthol, -naphthol, or kojic acid, with malononitrile and aromatic aldehydes (Scheme 1). 2. Experimental 2.1. Material and methods FeCl36H2O, FeCl24H2O, glycine, and all other chem-

Synthesis, biological assessment, and molecular modeling ...

Aug 01, 2012· The synthesis, pharmacological analysis and molecular modeling of the readily available racemic tacrine analogs 21–30, bearing the 7-aryl-9,10,11,12-tetrahydro-7H-benzo[7,8]chromeno[2,3-b]quinolin-8-amine heterocyclic ring system (II), prepared by Friedländer reaction of 2-amino-4-aryl-4H-benzo[h]chromene-3-carbonitriles (11–20) with cyclohexanone, are described in this paper.

The reaction of 2-amino-4H-pyrans with N-bromosuccinimide ...

A series of 2-aminochromene derivatives including 2-amino-benzo [h] chromene, 2-amino-benzo [f] chromene and 2-aminopyrano [3,2-h]quinolin derivatives was synthesized from arylaldehyde ...

Basic Alumina Catalyzed Synthesis of Substituted 2-Amino-2 ...

Synthesis of hydrotalcite using Al/Mg molar ratios of 1.0-3.0 by grinding method at room temperature is being described. ... A series of novel 3-amino-N-benzyl-1-aryl-1H-benzo[f]chromene-2 ...

Synthesis of 2-amino-4H-chromene derivatives under ...

ing method to construct the 2-amino-4H-chromene skeleton. 2. Experimental 2.1 Materials and methods Solvents used were of analytical grade. All melt-ing points were taken in open capillaries and are uncorrected. Thin-layer chromatography (TLC, on alu-minium plates precoated with silica gel, 60F254, 0.25mm thickness) (Merck, Darmstadt, Germany) was

1. Introduction - Hindawi

Our synthesis began with the reaction of a mixture of aromatic aldehydes 1a–h, malononitrile (2), and resorcinol (3) in refluxing ethanol containing a catalytic amount of Rochelle salt to give 2-amino-4-aryl-7-hydroxy-4 H-chromene-3-carbonitriles 6a–h (Scheme 1), (Table 1).The structures of the isolated products 6a-h were confirmed on the basis of their elemental analyses and spectral data.