Reaction Of 2-naphthol Research Articles

A Simple and Reliable Dispersive Liquid-Liquid Microextraction with Smartphone-Based Digital Images for Determination of Carbaryl Residues in Andrographis paniculata Herbal Medicines Using Simple Peroxidase Extract from Senna siamea Lam. Bark.

A simple and reliable dispersive liquid-liquid microextraction (DLLME) coupled with smartphone-based digital images using crude peroxidase extracts from cassia bark (Senna siamea Lam.) was proposed to determine carbaryl residues in Andrographis paniculata herbal medicines. The method was based on the reaction of 1-naphthol (hydrolysis of carbaryl) with 4-aminoantipyrine (4-AP) in the presence of hydrogen peroxide, using peroxidase enzyme simple extracts from cassia bark as biocatalysts under pH 6.0. The red product, after preconcentration by DLLME using dichloromethane as extraction solvent, was measured for blue intensity by daily life smartphone-based digital image analysis. Under optimized conditions, good linearity of the calibration graph was found at 0.10–0.50 mg·L−1 (r2 = 0.9932). Limits of detection (LOD) (3SD/slope) and quantification (LOQ) (10SD/slope) were 0.03 and 0.09 mg·L−1, respectively, with a precision of less than 5%. Accuracy of the proposed method as percentage recovery gave satisfactory results. The proposed method was successfully applied to analyze carbaryl in Andrographis paniculata herbal medicines. Results agreed well with values obtained from the HPLC-UV method at 95% confidence level. This was simple, convenient, reliable, cost-effective and traceable as an alternative method for the determination of carbaryl.

Preparation and Catalytic Application of 3-Methyl-1-Sulfonic Acid Imidazolium Copper (II) Trichloride for the Synthesis of 1-(α-Aminoalkyl)-2-Naphthols

3-Methyl-1-sulfonic acid imidazolium copper (II) trichloride, {[Msim]CuCl3}, as a new homologue of 3-methyl-1-sulfonic acid imidazolium chloride {[Msim]Cl}, was prepared and studied by several analyses such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDX). [Msim]CuCl3 was tested, as an efficient catalyst, for the solvent-free preparation of some Betti bases namely 1-(α-aminoalkyl)-2-naphthols by the reaction of 2-naphthol with various aromatic aldehydes and amines such as pyrrolidine, piperidine, 1-methylpiperazine and morpholine at 100 °C to give a wide range of products.

Palladium-Catalyzed Dearomative Domino-Heck Reaction of Naphthols

Palladium-Catalyzed Dearomative Domino-Heck Reaction of Naphthols

Synthesis of Vinylnaphthofurans and NMR Analysis of their Photoswitching

AbstractAn easy synthesis of photochromic vinylnaphthofurans by the acid‐catalyzed one‐pot reaction of naphthols with but‐2‐yne‐1,4‐diols is described. These uncolored polyaromatic compounds are activated by UV light, at room temperature, and converted through a stilbene‐type electrocyclization into a thermally stable orange species, which can be switched back using visible light. The behavior of these photoswitches was elucidated using NMR, which allowed to identify the photoisomers and some side‐products, formed after prolonged UV irradiation.

Adipic Acid as a Biodegradable Solid Acid Catalyst for One-Pot, Three Component Synthesis of 1-Amidoalkyl-2-naphthols

Background: 1-Amidoalkyl-2-naphthols are an attractive group of organic compounds that can be converted to oxazine heterocycles and aminoalkyl naphthols. The derivatives of 1- amidoalkyl-2-naphthols have significant biological activities and act as drug candidates. Methods: 1-Amidoalkyl-2-naphthols were synthesized via the three-component condensation reaction of 2-naphthol, acetamide/benzamide and various aldehydes in the presence of 10 mol% of adipic acid as an organocatalyst under solvent-free conditions at 120°C. Results: A simple, efficient, and operative method for the synthesis of 1-amidoalkyl-2-naphtholes in the presence of adipic acid as the biodegradable catalyst is introduced. Easy operation, acceptable reaction times, eco-friendly, availability of starting materials, simple separation of products, and high yields of products are the significant results of this method. Conclusion: In this study, 1-amidoalkyl-2-naphthols were synthesized using commercially available reactants in excellent yields and relatively shorter times. In this process, microwave or ultrasonic waves were not used to provide energy for the reaction.

One-Pot Multicomponent Synthesis of 2-Amino-4-Aryl-4H-Benzo[h]Chromene Derivatives

A simple and efficient procedure has been developed for the one-pot synthesis of a series of novel benzochromene derivatives by the multicomponent reaction of 1-naphthol, aromatic aldehydes and benzenesulfonyl acetonitrile under microwave irradiation, using piperidine as catalyst and ethanol as solvent. This methodology was shown many advantages, including higher reaction yields, broad substrate scopes, experimental simplicity, short time and easily available starting materials. The synthesized compounds are characterized by 1H NMR and HR-ESI-MS.

Transition Metal- and Oxidant-Free Base-Mediated Selenation of Bicyclic Arenes at Room Temperature.

Bicyclic arenyl selenides are of much importance because of their pharmaceutical applications. A simple method for their synthesis has been developed by a reaction of 2-naphthol and styrenyl selenocyanate/diaryl diselenide in the presence of a base at room temperature. The selenation occurs exclusively at the 1-position of 2-naphthol unit. The reactions are relatively fast (2–4 h) and high yielding. A library of substituted naphthyl styrenyl and naphthyl aryl selenides are obtained by this procedure.

Diversiform Reactivity of Naphthols in Asymmetric Dearomatization or O‐Alkylation Reactions with Aziridines

AbstractHere, we present a catalytic asymmetric and site‐selective reaction of naphthols, realizing diversiform reactions in asymmetric dearomatization or O‐alkylation with aziridines, and the reason for the switchable reactivity is formally analyzed with different type of substrates under different conditions.magnified image

Green and Efficient One-Pot Synthesis of 2-Amino-3-phenylsulphonyl-4H-chromenes under Solvent-Free Conditions

A green and convenient method for the synthesis of 2-amino-3-phenylsulphonyl-4H-chromenes by a one-pot three-component condensation of 1-naphthol, phenylsulphonylacetonitrile and aromatic aldehydes under solvent-free conditions using potassium phosphate tribasic trihydrate as an efficient catalyst is described. The reaction of 1-naphthol with phenylsulphonylacetonitrile and various aromatic aldehydes was carried out under solvent-free conditions at 100 °C using 10 mol% of potassium phosphate tribasic trihydrate as a catalyst. The results show that aromatic aldehydes containing electron-donating groups or electron-withdrawing groups could react smoothly to give the corresponding products in good to excellent yields. It was also found that potassium phosphate tribasic trihydrate can be recycled at least four times without loss of activity. High yields, short reaction times, ease of handling, cheap and reusable catalyst, mild and environmentally begin reaction conditions are the advantages of this procedure.

Synthesis and Conformational Behaviour of Enantiomeric Naphthoxazinoquinoxalinone Derivatives

New non‐racemic naphth[1,3]oxazino[3,2‐a]quinoxalinones have been synthesized starting from an enantiomeric hexahydroquinoxalinone and 1‐aminoalkyl‐2‐naphthols or 2‐aminoalkyl‐1‐naphthols. The enantiopure annelational analogues naphth[1,3]oxazino[3,4‐a]quinoxalinone derivatives were also synthesized from the reactions of naphthols and the non‐racemic quinoxalinone followed by a ring‐closing reaction with formaldehyde. In addition to the study of the conformational behaviour of the new heteropolycycles, the diastereoselectivity and formation of the possible diastereomers were examined by NMR analysis. Theoretical calculations were performed to confirm the experimental results.

A carbon quantum dot-encapsulated micellar reactor for the synthesis of chromene derivatives in water

An efficient protocol for the synthesis of 4H-chromene derivatives via a one-pot multicomponent reaction was developed using a self-assembled catalyst system. The self-assembling nature of the fabricated catalyst is unique, consisting of carbon-quantum dots (CQDs) and ionic liquids (ILs). At the critical micelle concentration (CMC), the ILs organize themselves as micelles and the CQDs are trapped inside, forming a CQD-colloidal reaction system (CRS). The reactions of naphthols with aromatic aldehydes and malononitrile in the CQD-CRS system gave excellent yields of 4H-chromene derivatives at room temperature in 15min upon sonication. The present method provides a high EcoScale score and a low E-factor, validating the greenness of the procedure. The self-aggregating nature of the catalyst is highly advantageous as it can be recycled and reused provided the CMC is maintained. To the best of our knowledge, this is the first example of a self-assembled CQD-based catalyst in aqueous media. CQD-CRS can be considered a designer’s catalyst, as by changing the ILs/CQDs components, multiple variants could be produced under different solvent conditions.

Silver nanoparticles: An efficient and versatile reagent for the synthesis of 1-amidoalkyl-2-naphthols

ABSTRACTSilver nanoparticles have been prepared and shown to efficiently catalyze the one-pot, three-component reaction of 2-naphthol, aldehydes, and acetamide at reflux, to afford the corresponding 1-amidoalkyl-2-naphthols at high yield. The present method has several advantages such as high yields, easy purification, mild reaction conditions, easy work-up, survival of different functional groups, and short reaction times.

Correction: Phosphine-catalyzed Friedel-Crafts reaction of naphthols with para-quinone methides: expedient access to triarylmethanes.

Correction for 'Phosphine-catalyzed Friedel-Crafts reaction of naphthols with para-quinone methides: expedient access to triarylmethanes' by Tao Zhou et al., Org. Biomol. Chem., 2017, DOI: 10.1039/c7ob00911a.

Organocatalytic Friedel–Crafts Alkylation/Lactonization Reaction of Naphthols with 3‐Trifluoroethylidene Oxindoles: The Asymmetric Synthesis of Dihydrocoumarins

AbstractNaphthols and 3‐trifluoroethylidene oxindoles were found to undergo an asymmetric Friedel–Crafts alkylation/lactonization reaction, catalyzed by only 2.5 mol % of a quinine‐derived squaramide catalyst, to afford the corresponding α‐aryl‐β‐trifluoromethyl dihydrocoumarin derivatives in high yields (up to 99 %) with excellent enantio‐ and diastereoselectivities (up to 98 % ee, >20:1 d.r.). Importantly, the lactonization proceeded by nucleophilic attack of the naphthol hydroxy group at the amide motif of the oxindoles under mild reaction conditions. This protocol represents a new strategy for the formation of dihydrocoumarins by an efficient intramolecular amide C−N bond‐cleavage and esterification process.

Organocatalytic Friedel-Crafts Alkylation/Lactonization Reaction of Naphthols with 3-Trifluoroethylidene Oxindoles: The Asymmetric Synthesis of Dihydrocoumarins.

Naphthols and 3-trifluoroethylidene oxindoles were found to undergo an asymmetric Friedel-Crafts alkylation/lactonization reaction, catalyzed by only 2.5 mol % of a quinine-derived squaramide catalyst, to afford the corresponding α-aryl-β-trifluoromethyl dihydrocoumarin derivatives in high yields (up to 99 %) with excellent enantio- and diastereoselectivities (up to 98 % ee, >20:1 d.r.). Importantly, the lactonization proceeded by nucleophilic attack of the naphthol hydroxy group at the amide motif of the oxindoles under mild reaction conditions. This protocol represents a new strategy for the formation of dihydrocoumarins by an efficient intramolecular amide C-N bond-cleavage and esterification process.

Selective synthesis of 1-(1-naphthyloxy)-2,3-epoxypropane from 1-naphthol and epichlorohydrin under solid–liquid phase transfer catalysis: a waste minimization strategy

Selective organic transformation is a basic theme which needs to be followed to have a waste free, clean and green process. Phase transfer catalysis (PTC) is a synthetic technique that satisfies this criterion very well in which reaction rates and selectivities are enhanced by several folds, thereby decreasing processing costs and hazardous conditions. Solid–liquid (S–L) PTC is better than liquid–liquid (L–L) PTC since the rates of reactions are intensified by order(s) of magnitude and total selectivity can be obtained due to suppression of aqueous-phase reactions. 1-(1-Naphthyloxy)-2,3-epoxypropane is an intermediate in the synthesis of β-blocker drugs propranolol and nadolol. In the current work, synthesis of 1-(1-naphthyloxy)-2,3-epoxypropane was carried out by the reaction of 1-naphthol and epichlorohydrin by using a variety of phase transfer catalysts among which tetra-n-butyl ammonium bromide (TBAB) was the best catalyst at 70 °C under S–L PTC. The effects of various parameters affecting the conversion and initial rates of O-alkylation were studied to establish kinetics and mechanism. Selectivity of 100% for 1-(1-naphthyloxy)-2,3-epoxypropane was observed. The reaction followed pseudo-first-order kinetics. S–L PTC is a waste minimization strategy since no by-products are formed and the process is intensified reducing reactor volume and processing time.

A one-pot synthesis of 1,2-dihydro-1-arylnaphtho[1,2-e][1,3]oxazine-3-ones catalyzed by iron(III) phosphate under solvent-free condition

ABSTRACTAn efficient green route for the preparation of naphthoxazinones, applying a three-component one-pot condensation reaction of 2-naphthol, aromatic aldehyde, and urea in the presence of iron(III) phosphate under solvent-free conditions, has been developed. The present procedure offers several advantages such as short reaction time, simple workup, recovery, and reusability of the catalyst. In addition, some new compounds were synthesized, and procedure could easily be scaled up.

Novel and potent Lewis acid catalyst: Br2-catalyzed Friedel–Crafts reactions of naphthols with aldehydes

ABSTRACTA discovery that the inexpensive Br2 can serve as a potent Lewis acid catalyst for bis(2-hydroxy-1-naphthyl)methanes synthesis is presented. Under the catalysis of Br2 at room temperature, naphthols reacted smoothly with various aldehydes with high efficiency and broad substrate scope. This reaction used to require highly acidic conditions and/or high temperature and/or pressure, and sometimes featured poor yields. Moreover, theoretical calculations suggested that Br2 is a potent Lewis acid to activate the carbonyl group, yet it was not the primary cause for the remarkable activity of Br2 in the current communication.

Efficient and Eco-Friendly Procedure for the Synthesis of 2-Amino-4H-Chromenes Catalyzed by Diammonium Hydrogen Phosphate

An efficient and eco-friendly protocol for the preparation of 2-amino-4H-chromenes employing a multi-component, one-pot condensation reaction between aromatic aldehydes, malononitrile and 1-naphthol has been developed. The reaction of 1-naphthol with malononitrile and various aromatic aldehydes was carried out in water-ethanol (1:1) at reflux using 20 mol% of diammonium hydrogen phosphate as catalyst. The results show that aromatic aldehydes containing electron-donating groups or electron-withdrawing groups could react smoothly to give the corresponding products in good to excellent yields. It was also found that diammonium hydrogen phosphate can be recycled at least four times without loss of activity. The operational simplicity, easy work-up, short reaction time, together with the use of non-toxic, commercially available, inexpensive and recyclable catalyst are remarkable features of the procedure.

Alkylation of Asphaltenes Using a FeCl3Catalyst

Friedel–Crafts alkylation as a strategy to convert asphaltenes to maltenes was investigated. It was postulated that conversion of polar hydroxyl groups in the asphaltenes would make the product more soluble in light hydrocarbons. Reactions were performed with oilsands bitumen-derived materials using FeCl3 as a catalyst and o-xylene and methanol, separately. Only the reaction of o-xylene with asphaltenes was mildly beneficial; it resulted in 6% conversion of asphaltenes to maltenes and an increase of 9% in straight-run distillate and vacuum gas oil. The reactions of o-xylene with maltenes and bitumen were detrimental, as was all alkylation reactions with methanol. To better understand the nature of the conversion, the reactions were repeated with model compounds. With 2-naphthol, it was found that dimerization of 2-naphthol to produce (1,1′-binaphthalene)-2,2′-diol (BINOL) and the subsequent coordination with iron were the two dominant reactions. The adverse consequences of FeCl3-catalyzed conversion could be explained by such intermolecular addition reactions. The reaction of 2-naphthol with methanol and FeCl3 also caused some chlorination of the product. The possibility that FeCl3 as a catalyst affected ethers was explored by performing the reaction with dibenzyl ether as feed. It was found that the ether bonds were cleaved. In the presence of o-xylene, ether cleavage was followed by C-alkylation. The increase in maltenes after the reaction of o-xylene with asphaltenes was better explained by C-alkylation following ether cleavage than the reaction between o-xylene and the hydroxyl groups in the asphaltenes. The reaction of dibenzyl ether with methanol produced benzaldehyde, rearrangement products, and heavy gums.