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The work presented a facile, one-step procedure as a green assembly process for preparing silver tungstate nanorod by hydrothermal technique via a chemical reaction between silver nitrate and sodium tungstate. The synthesized precipitate was characterized using X-ray diffraction (XRD) transmission electronic microscope (TEM) and scanning electron microscopy (SEM) to ensure the formation of crystallization and single-phase material. The prepared nanorods undergo a catalytic evaluation to synthesize tetrahydrobenzo[a] xanthene-11-one derivatives by a one-pot reaction of β-naphthol, dimedone, and aromatic aldehyde with a catalytic amount of silver tungstate under the solvent-free condition at 60–70 °C. ArgC is one of the L-arginine biosynthetic pathways of mycobacterium tuberculosis. The molecular docking explains that all the synthesized compounds presented high ligand ability for the targeted enzyme compared with xanthene-9-carboxylic acid as a reference. [ABSTRACT FROM AUTHOR]

We report that ceric ammonium nitrate mediated the synthesis of 1, 3-oxazine derivatives under the green method. In the reaction, 20 mol% catalysts are sufficient for the complete conversion of the reaction. The condensation reaction of β-naphthol with formaldehyde and primary amines those containing electron-donating as well as electron-withdrawing substituents under the aqueous reaction condition at ambient temperature in the presence of ceric ammonium nitrate has been developed as an efficient and eco-friendly precursor for the determination of 1, 3-oxazine derivatives. This approach has numerous benefits beyond conventional systems, notably ease of use, expense, reusability of the catalyst, and faster reaction times. [ABSTRACT FROM AUTHOR]

The article discusses the challenges and strategies involved in the dearomatization of ¿-unsubstituted ß-naphthols in organic synthesis. It explores various methods, including catalytic reduction reactions, Lewis acid catalysis, transition-metal-catalyzed reactions, and gold-catalyzed reactions, which offer efficient ways to synthesize complex spirocyclic molecules and functional spiro polymers. The article also acknowledges the limitations and challenges associated with these reactions. It concludes by suggesting that new strategies for catalytic asymmetric dearomatization reactions will likely be discovered in the future. [Extracted from the article]

A catalyst‐free intermolecular dearomatization reaction of β‐naphthols with hypervalent‐iodine‐based nitrooxylating reagent is reported. Various nitrooxylated β‐naphthalenones bearing a quaternary carbon stereogenic center were obtained smoothly in good to excellent yields (up to 87 %) under mild conditions. This method features mild conditions, broad substrate scope and excellent chemoselectivity. [ABSTRACT FROM AUTHOR]

A new approach for synthesizing selenylated naphthalene derivatives is described herein, employing trichloroisocyanuric acid (TCCA) as the oxidizing agent. The developed protocol yielded 18 compounds, with yields ranging from 32 % to 90 %. Additionally, the reaction was conducted under mild conditions, utilizing ethanol as the solvent at room temperature, demonstrating good atom economy. The key aspect of the protocol is the in situ generation of electrophilic selenium species through the reaction of diorganyl diselenides and TCCA. [ABSTRACT FROM AUTHOR]

Functionalized arenes and arenols have diverse applications in chemical synthesis and material chemistry. Selective functionalization of arenols is a topic of prime interest. In particular, direct alkylation of arenols using alcohols is a challenging task. In this report, a ruthenium pincer catalyzed direct α‐alkylation of β‐naphthol using primary alcohols as alkylating reagents is reported. Notably, aryl and heteroaryl methanols and linear and branched aliphatic alcohols underwent selective alkylation reactions, in which water is the only byproduct. Notably, catalytically derived α‐alkyl‐β‐naphthol products displayed high absorbance, emissive properties, and quantum yields (up to 93.2 %). Dearomative bromination on α‐alkyl‐β‐naphthol is demonstrated as a synthetic application. Mechanistic studies indicate that the reaction involves an aldehyde intermediate. DFT studies support this finding and further reveal that a stoichiometric amount of base is required to make the aldol condensation as well as elementary steps required for regeneration of catalytically active species. In situ‐generated water molecule from the aldol condensation reaction plays an important role in the regeneration of an active catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • Both resorcinol and β-naphthol effectively reduce cloud point of Triton X-100 solutions. • About 10–15 % of resorcinol and 60–70 % of β-naphthol transfer to the micellar phase. • Different mechanisms of clouding by these agents were proposed. • Hg(II) can be extracted in studied systems using 8-hydroxyquinoline as a ligand. The clouding behavior of Triton X-100 solutions was investigated in the presence of resorcinol or β-naphthol. Both agents can effectively decrease the cloud point of Triton X-100 solutions. Resorcinol is active over a wider pH range, while β-naphthol is required at concentrations 10–50 times lower than resorcinol. It was also shown that about 60–70 % of β-naphthol transfers to the micellar phase, whereas resorcinol barely enters the micellar phase (about 10–15 %). Thermodynamic parameters of the clouding process were also calculated, revealing no significant differences between thermodynamic parameters for these two substances studied. Based on the results obtained, we assume different mechanisms of phase separation by these agents. Using the systems studied, mercury cloud point extraction was successfully carried out with 8-hydroxyquinoline as a ligand. The optimal parameters for extraction were determined as follows: pH of 8 (β-naphthol) and 6 (resorcinol), ligand concentration of 0.03–0.26 mmol L−1, and surfactant concentration of 1.7 g L−1. [ABSTRACT FROM AUTHOR]

The synthesis of 2-amino-2-chromenes under solvent-free conditions is disclosed here using a silica triflate catalyzed one-pot three component condensation. The 2-amino-2-chromenes product was obtained in outstanding yield under the optimal reaction conditions of a range of functionalized aromatic aldehydes, malononitrile, and α/β-naphthol. This procedure stands out for its wide substrate scope, reduced reaction time, great yield, functional group compatibility, operational simplicity, and outstanding catalyst recyclability. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Inconspicuous yet carbon‐based leaving groups has presented us with novel C−C bond cleaving avenues for organic transformations over the past few years. This initial review of the emerging field aims to highlight the chemistry that allows C−C bond cleavage in unstrained molecules in mild and sometimes metal‐free reaction conditions. A wide variety of carbon‐based leaving groups has been reported that demonstrate its vast utility for the formation of new C−H, C−N, C−C, C−O, and C−S bonds. The review has been divided in three main sections discussing the leaving group aptitude of active methylene compounds, active methyl compounds and electron‐rich arenes. With uncomplicated pre‐requisites for a carbon‐based fragment to act as leaving groups, we expect more such efficient leaving groups will be identified in the near future. [ABSTRACT FROM AUTHOR]

A facile and eminent method has been reported for the preparation of amido alkyl naphthols. Amido alkyl naphthol derivatives were synthesized by the condensation of pyrazole aldehydes, β-naphthol andacetamidein the presence of a heterogeneous SiO2 supported sodium hydrogen sulphate catalyst using acetic acid as solvent. This protocol is advantageous for its shorter reaction hours, simplest workup technique, excellent yields with easy recovery and reusability of the catalyst. ¹H, and 13C Nuclear magnetic resonance, Fourier transform infrared and Mass Spectroscopy were utilized for the characterization of synthesized products. [ABSTRACT FROM AUTHOR]

Fused aromatic systems with homo and heterodimer stacked conformation shows effective π-π interactions in the gas phase. Here, we have investigated the π-π stacking interaction of some fused aromatic rings (viz. α-naphthol, β-naphthol, naphthalene etc.) and tried to make their stacked dimers to analyze the actual stacking interaction for different conformations. All these stacked models show strong stacking interaction between the homo dimer of such fused ring systems. It is also an important aspect to analyze the strength of stacking interaction energy with a thin fused dimer of aryl systems. All kinds of interaction energies including the electron-electron correlation energy can be calculated properly by using the appropriate DFT method. Herein, the stacking interaction energy of the stacked systems of naphthalene, α-naphthol, and β-naphthol has been accounted by using the M062X method. [ABSTRACT FROM AUTHOR]

An efficient green technique has been developed for the synthesis of some biologically active 12-aryl or 12-alkyl 8,9,10,12-tetrahydrobenzo[a]xanthenes-11-one and 3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione derivatives have been described. This process arranged a three-component one-pot condensation of aldehydes, 2-naphthol, and dimedone mediated by 2-aminophenol and has offered an excellent scope of tailoring a large number of xanthene derivatives with good to charming yields. Short reaction time, straightforward, easy product isolation technique, non-toxic catalyst, and above all metal-free process are noteworthy advantages of this method. [ABSTRACT FROM AUTHOR]

The present paper shows that lanthanum(III) nitrate hexahydrate can be used as mild and environment friendly homogeneous catalyst for an efficient one-pot multi-component synthesis of biologically active 1,8-dioxo-octahydroxanthene and 14H-dibenzo[a,j]xanthene derivatives. The solvent free condensation reaction of aromatic aldehydes and dimedone or β-naphthol was carried out at 70-80ºC during 10-30 min. The advantages of this eco-friendly synthesis route are numerous, and include the use of an inexpensive catalyst, high to excellent yield, short reaction time and high catalytic activity that can make this method an interesting alternative to multi-step approaches.

A new green protocol has been developed for synthesis of tetrahydrobenzo[a]xanthen-11-ones via a three component, one-pot condensation reaction of dimedone, β-naphthol and aromatic aldehydes using nano-AlPO4/Ti (IV) (NAP-Ti(IV)) as a reusable and novel catalyst at 90 °C under solvent-free condition. Short reaction times, high yields, scale up and easy work-up are advantages of this protocol. The prepared nano-AlPO4/Ti(IV) was fully characterized by EDX, XRD, SEM, IR analysis. The obtained tetrahydrobenzo[a]xanthen-11-ones were characterized by various methods such as FT-IR, 1HNMR. [ABSTRACT FROM AUTHOR]

A novel nano-magnetic-supported phenyltetrazolethiol-based Ni complex (Fe3O4@SiO2@ CPTMS@PhenTetThiol@Ni) was synthesized, characterized with different techniques and used as a heterogeneous nano-catalyst in the following two sets of compounds: (a) synthesis of amidoalkyl naphthols from the reaction of aromatic aldehyde, 2-naphthol and acetamide/benzamide in solvent-free condition at 75 °C for an appropriate time and (b) synthesis of chromenes from the reaction of aldehyde, dimedone and malononitrile under solvent-free condition at 75 °C for an appropriate time. [ABSTRACT FROM AUTHOR]

A simple and efficient method for the synthesis of 2-(2-(aryl)naphtho[2,1-b]furan-1-yl)acetic acid derivatives via an one-pot three-component reaction of Meldrum's acid, arylglyoxals, and ß-naphthol in the presence of triethylamine (Et3N) is reported. The protocol avoids the use of expensive catalysts, chromatographic separation and provides a wide range of novel naphtho[2,1-b]furans in excellent yields. Spectral data and elemental analysis have characterized the newly synthesized compounds. [ABSTRACT FROM AUTHOR]

• Layered double hydroxides (LDH) are a suitable option for the removal of α- and β-naphthol isomers. • The nature of the anion in the interlayer has an impact on the removal of naphthols. • The molar ratio M2+:M3+ and organic interlayers improve removal performance. • The MgAl-LDH, NiAl-LDH, and CoAl-LDH show the same tendencies for removal. The present work describes a quick, simple, and efficient method based on the use of layered double hydroxides (LDH) coupled to dispersive solid phase micro-extraction (DSPME) to remove α-naphthol (α-NAP) and β-naphthol (β-NAP) isomers from water samples. Three different LDHs (MgAl-LDH, NiAl-LDH, and CoAl-LDH) were used to study how the interlayer anion and molar ratio affected the removal performance. The critical factors in the DSPME procedure (pH, LDH amount, contact time) were optimized by the univariate method under the optimal conditions: pH, 4-8; LDH amount, 5 mg; and contact time, 2.5 min. The method can be successfully applied in real sample waters, removing NAP isomers even in ultra-trace concentrations. The large volume sample stacking (LVSS-CE) technique provides limits of detections (LODs) of 5.52 µg/L and 6.36 µg/L for α-naphthol and β-naphthol, respectively. The methodology's precision was evaluated on intra- and inter-day repeatability, with %RSD less than 10% in all cases. The MgAl/Cl−-LDH selectivity was tested in the presence of phenol and bisphenol A, with a removal rate of >92.80%. The elution tests suggest that the LDH MgAl/Cl−-LDH could be suitable for pre-concentration of α-naphthol and β-naphthol in future works. [ABSTRACT FROM AUTHOR]

A simple, efficient, and green procedure for the solvent-free synthesis of 1-amido/thioamidoalkyl-2-naphthols by one-pot stirring of starting reactants at 100 °C has been introduced. By utilizing salicylic acid (SA) as the catalyst, the reaction of aryl aldehydes, 2-naphthol, and acetamide/benzamide/urea/thiourea were successfully performed, and 1-amido/thioamidoalkyl-2-naphthols were obtained in good to high isolated yields. The notable advantages of this method over some previous methods are the availability of catalyst, atom efficiency, not using any solvent for reaction, relatively green conditions, no need for catalyst synthesis, relatively shorter reaction times, and no specialized equipment (microwave or ultrasound) or purification techniques are needed. DOI: http://dx.doi.org/10.17807/orbital.v11i1.1355

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1-Methyl-3-sulfo-1H-imidazol-3-ium chloride ([Msim]Cl) catalyzed the condensation of β-naphthol with aromatic aldehydes under microwave irradiation. This method is efficient to synthesize dibenzoxanthene derivatives in excellent yields, and the catalyst can be reused up to three times without significant loss of activity. [ABSTRACT FROM AUTHOR]

Using different chromatographic methods, four new compounds were isolated from the aerial parts of Suaeda monoica (Chenopodiaceae) along with 2-hydroxy-1-naphthoic acid (SCM-3). The structures of the new compounds were established as 6′-hydroxy-10′-geranilanyl naphtha-1-oate (SMC-1), 4,4,8β,10β-Tetramethyl-9β-isobutanyl decalin-13-ol-13-O-β-D-xylopyranoside (SCM-2), 6′-(2-hydroxynaphthalen-3-yl) hexanoic acid (SCM-4) and 1′-(2-Methoxy-3-naphthyl)-4′-(2′'-methylbenzoyl)- n -butane (SMC-5) by IR, EIMS and NMR (1 & 2D) analyses. All compounds (50 μg/mL) were tested for cell proliferative potential on cultured human liver cell HepG2 cells by MTT assay. The results revealed a marked cell proliferative potential of all compounds (1.42–1.48 fold) as compared to untreated control. The results of molecular docking and binding with specific proteins such as PTEN (Phosphatase and Tensin homolog) and p53 also justify the cell proliferative potential of the isolated compounds. Glide program with Schrodinger suit 2018 was used to evaluate the binding between SMC compounds and proteins (PTEN and p53). The binding affinity of all compounds was in order of 104–105 M−1 towards both PTEN and p53. All the SMC compounds have been found to bind at the active site of PTEN, thereby may prevent the binding of phosphatidylinositiol 3,4,5-triphosphate (PI3P). In the locked position, PTEN would not be able to hydrolyze PI3P and hence the PI3P regulated signaling pathway remains active. Similarly, SMC molecules were found to interact with the amino acid residues (Ser99, Thr170, Gly199, and Asp224) which are critically involved in the formation of tetrameric p53. The blockage of p53 to attain its active conformation thus may prevent the recruitment of p53 on DNA and hence may promote cell proliferation. [ABSTRACT FROM AUTHOR]

A small molecule library of trans-1,3-diaryl-1H-naphtho[1,2-e][1,3]oxazines 4 is synthesised through multicomponent reactions involving aliphatic amines, aromatic aldehydes and β-naphthol using a heterogeneous catalyst, SiO2.HClO4, and ethanol as the solvent. The anti-inflammatory activities of the synthesised compounds are evaluated together with in silico studies. 1,3-Bis(4-chlorophenyl)-2-ethyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazine (4h) shows the best activity with IC50 = 4.807 µg/mL in the heat-induced haemolysis, while 1,3-Bis(5-bromothiophen-2-yl)-2-ethyl-2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazine (4c) shows significantly high anti-inflammatory activity (IC50 = 5.5 µg/mL) in comparison with standard drugs, such as sodium diclofenac. In addition, molecular docking simulation study confirms the in-depth molecular interaction of the two lead compounds, 4c and 4h with better binding affinities and docking scores at the active site of the COX-2 enzyme compared with diclofenac. Highlights: SiO2.HClO4 as a heterogeneous catalyst in the synthesis of naphtho[1,2-e][1,3]oxazine. The anti-inflammatory activities of the synthesised compounds were also analysed along with the in silico studies. The importance of naphtho[1,2-e][1,3]oxazine are highlighted. The catalyst is easily accessible and reusable. [ABSTRACT FROM AUTHOR]

Lactic acid, as a biological, eco-friendly, and inexpensive compound, efficiently catalyzed the synthesis of 8,10-dimethyl-12-aryl-12H-naphtho[1′,2′:5,6]pyrano[2,3-d] pyrimidine-9,11-dione derivatives by an efficient one-pot, three-component reaction between aromatic aldehydes, β-naphthol, and 6-amino-1,3-dimethyl uracil at 100°C under solvent-free conditions. The benefits of the reaction are good yields, simple procedure, short reaction time, easy work-up, and cleaner reaction profiles. [ABSTRACT FROM AUTHOR]

A novel one‐pot three‐component condensation reaction of an aldehyde, 2‐aminopyrimidine and 2‐naphthol to afford the corresponding 2‐aminopyrimidinomethylnaphtols in good yields. The remarkable features of this new procedure are high conversions, short reaction time, clean reaction profiles, and environmentally benign and simple work‐up procedures. [ABSTRACT FROM AUTHOR]

A general synthetic route to dibenzoxanthenes has been developed using 1,4-diazanium-bicyclo[2.2.2]octane diacetate as a new bis ionic liquid under thermal and solvent free condition. This method provides several advantages such as simple work-up, environmental friendliness and shorter reaction time along with high yields. All of synthesized compounds were characterized by Infrared spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy and Elemental analyses.

Leishmaniasis remains a significant global health concern, with current treatments relying on outdated drugs associated with high toxicity, lengthy administration, elevated costs, and drug resistance. Consequently, the urgent need for safer and more effective therapeutic options in leishmaniasis treatment persists. Previous research has highlighted selenium compounds as promising candidates for innovative leishmaniasis therapy. In light of this, a library of 10 selenium-containing diverse compounds was designed and evaluated in this study. These compounds included selenium-substituted indole, coumarin, chromone, oxadiazole, imidazo[1,2- a ]pyridine, Imidazo[2,1- b ]thiazole, and oxazole, among others. These compounds were screened against Leishmania amazonensis promastigotes and intracellular amastigotes, and their cytotoxicity was assessed in peritoneal macrophages, NIH/3T3, and J774A.1 cells. Among the tested compounds, MRK-106 and MRK-108 displayed the highest potency against L. amazonensis promastigotes with reduced cytotoxicity. Notably, MRK-106 and MRK-108 exhibited IC 50 values of 3.97 µM and 4.23 µM, respectively, and most of the tested compounds showed low cytotoxicity in host cells (CC 50 > 200 µM). Also, compounds MRK-107 and MRK-113 showed activity against intracellular amastigotes (IC50 18.31 and 15.93 µM and SI 12.55 and 10.92, respectively). In conclusion, the identified selenium-containing compounds hold potential structures as antileishmanial drug candidates to be further explored in subsequent studies. These findings represent a significant step toward the development of safer and more effective therapies for leishmaniasis, addressing the pressing need for novel and improved treatments.

A simple, efficient, and green procedure for the solvent-free synthesis of 1-amido/thioamidoalkyl-2-naphthols by one-pot stirring of starting reactants at 100 °C has been introduced. By utilizing salicylic acid (SA) as the catalyst, the reaction of aryl aldehydes, 2-naphthol, and acetamide/benzamide/urea/thiourea were successfully performed, and 1-amido/thioamidoalkyl-2-naphthols were obtained in good to high isolated yields. The notable advantages of this method over some previous methods are the availability of catalyst, atom efficiency, not using any solvent for reaction, relatively green conditions, no need for catalyst synthesis, relatively shorter reaction times, and no specialized equipment (microwave or ultrasound) or purification techniques are needed. [ABSTRACT FROM AUTHOR]

A first example of Fe‐catalyzed dearomative amination of β‐naphthols with aryl azides is described. The method constructs a nitrogen‐containing quaternary carbon center catalyzed by cheap and readily available iron salt FeCl2, and affords a series of α‐amino‐β‐naphthalenones in good to excellent yields under simple and mild reaction conditions. Preliminary experimental and computational studies suggest that the reaction is probably initiated by iron‐iminyl diradical and followed by intramolecular hydrogen transfer to generate iron‐aminyl radical and finally an intramolecular radical combination reaction. [ABSTRACT FROM AUTHOR]

A one-pot three-component condensation reaction of 3-amino-5-methylisoxazole, aryl aldehyde and 2-naphthol to afford the corresponding 3-amino isoxazolmethylnaphthols in good to excellent yields. The remarkable features of this new procedure are high conversions, clean reaction condition, short reaction time, nonhazardous and environmentally friendly reaction condition, inexpensive and easily commercially availability of the catalyst and simple work-up procedures. [ABSTRACT FROM AUTHOR]

3 H -Naphtho[2.1- b ]pyran-2-carboxamides (3 H -Benzo[ f ]chromene-2-carboxamides) can be synthesized from a three-component cyclocoupling reaction of β-naphthol, propargyl alcohols and isocyanide in the presence of ZnI 2 and FeCl 3 under air atmosphere. The reaction is proposed to involve the formation of aryl-zinc (II) σ-bond and its α-addition to isocyanide. [ABSTRACT FROM AUTHOR]

An efficient synthesis is reported for tetrahydrobenzo[ a]xanthene-11-ones through a one-pot catalytic reaction by mixing β-naphthol, demidone and aromatic aldehydes in the presence of a catalytic amount of tetrachlorosilane (TCS) inmethylene chloride as solvent at ambient temperature compared with other catalysts derived from silicon. Aurora kinase inhibitors have attracted a great deal of interest as a new class of antimitotic agents and so the molecular docking study was carried out on the synthesized compounds compared with pentacyclic AKI-001 to discover a novel class of Aurora inhibitors based on a tetracyclic xanthene scaffold and understand the orientation and the interaction of each molecule inside the active site of the Aurora A enzyme. [ABSTRACT FROM AUTHOR]

(±)-Camphor-10-sulfonic acid (CSA) catalyzed condensation of 2-naphthol with both aliphatic/aromatic aldehydes at 80°C yielded 14-alkyl/aryl-dibenzoxanthenes as the sole product in high yields. However, the same condensation with benzaldehyde at 25°C afforded a mixture of intermediate 1,1-bis-(2-hydroxynaphthyl)phenylmethane and 14-phenyl-dibenzoxanthene while the condensation with aliphatic aldehydes at 25°C furnished the corresponding 14-alkyl-dibenzoxanthenes as the sole product. Moreover, condensation of 2-naphthol with aromatic/aliphatic aldehydes with low catalyst loading (2 mol%) was greatly accelerated under microwave irradiation to afford the corresponding 14-aryl/alkyl-dibenzoxanthenes as the sole product in high yields.

Grafting of SnCl4on the Fe3O4@SiO2nanoparticles afforded Fe3O4@SiO2-SnCl4as a novel inorganic heterogenous catalyst, which was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), Field Emission Scanning Electron Microscopy (FE-SEM), and transmission electron microscopy (TEM). In this research, we report a convenient and efficient direct protocol for the preparation of xanthene derivatives via condensation of β-naphthol, dimedone, or mixture of β-naphthol and dimedone with various aromatic aldehydes in the presence of the catalytic amount of Fe3O4@SiO2-SnCl4under ultrasonic irradiation. This procedure has a lot of advantages such as: very easy reaction conditions, absence of any tedious workup, or purification, and much milder method. The corresponding products have been obtained in excellent yields, high purity, and short reaction times. [ABSTRACT FROM AUTHOR]

A novel ternary g-C 3 N 4 /C@Bi 2 MoO 6 composite photocatalyst was prepared by a hydrothermal deposition method. Beta naphthol (β-naphthol) was effectively degraded over g-C 3 N 4 /C@Bi 2 MoO 6 composite under visible-light irradiation. The improved photocatalytic activity could be attributed to the efficient separation of photogenerated electrons and holes through the Z-scheme construction of g-C 3 N 4 /C@Bi 2 MoO 6 . Carbon film acted as an electron mediator to form the charge transmission-bridge between Bi 2 MoO 6 and g-C 3 N 4 , which provided sufficient contact area and strong combination between the semiconductors and the electron mediators. The optimized Z-scheme 10%g-C 3 N 4 /C@Bi 2 MoO 6 composite showed the highest photocatalytic activity. A possible photocatalytic mechanism of g-C 3 N 4 /C@Bi 2 MoO 6 was proposed by a trapping experiment, which could be ascribed to the oxidizing ability of the generated holes and light absorption as well as the reduced the electron–hole pairs recombination with the presence of g-C 3 N 4 and carbon in the composites. The photogenerated holes in the valence band of Bi 2 MoO 6 were the major species in the β-naphthol photocatalytic degradation process, and the accumulating electrons in the conduction band of g-C 3 N 4 could capture the molecular oxygen to form superoxide radicals to decompose β-naphthol. [ABSTRACT FROM AUTHOR]

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 (DABCO)-catalysed cyclisation of β-naphthol and 3-aryl-2-cyanoacrylates using water as a green solvent. All products precipitated from the reaction mixture and were isolated by simple filtration. No further workup nor purification was necessary. The structure of ethyl 3-amino-1-aryl-1H-benzo[ f]chromene-2-carboxylate was further confirmed by X-ray single crystal analysis. [ABSTRACT FROM AUTHOR]

The present study describes a rapid, simple and straightforward approach to the synthesis of 1,8-dioxo-octahydroxanthenes, 14-phenyl-14 H -dibenzo[ a , j ]xanthene and tetrahydrobenzoxanthene-11-ones under solvent-free conditions using sulfated polyborate as a highly efficient catalyst. The procedure offers several advantages including cleaner reaction profile, mild reaction condition, economic, recyclable and environmentally benign catalyst, high yields, simple experimental and workup procedures. While non-extractive work up/purification, along with reusability of catalyst make this method economically affordable for large scale. [ABSTRACT FROM AUTHOR]

A one-pot procedure is descibed for the synthesis of naphtho[2,1-b]furan-2(1H)-ones via a multicomponent reaction of aryl aldehydes, hippuric acid, acetic anhydride and β-naphthol in the presence of Nafion-H supported on silica-coated superparamagnetic iron oxide nanoparticles under microwave irradiation. The catalyst can be recovered easily and reused several times without significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Purpose. Research of the influence of biologically active semi-products as intensifiers in dyeing of polyamide fibrous materials. Methodology. Used electronic absorption spectra of solutions of polyamide fibrous materials, which is dyed with representatives ofanthraquinone and azo dyes with the addition of biologically active semi-products as intensifiers. Findings. Is shownthe possibility of using antibacterial and antimycotic drugs of wide action as intensifiers of the dyeing process of polyamide fibrous materials . Originality. Were establisheddependences of color intensities when biologically active semiproducts were introduced as intensifiers Practical value. Going intensification of coloring at the use of biologically active products with simultaneous provision of antibacterial effect. [ABSTRACT FROM AUTHOR]

An expeditious procedure for the synthesis of 14- aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes through one-pot pseudo three component condensation of β-naphthol or dimedone with various aryl aldehydes is described. This greener protocol is catalyzed by phosphosulfonic acid, and proceeds efficiently in the absence of any organic solvent under optimized, mild, green and environmentally benign reaction conditions in high yields within 20-55 minutes.

The crystal structure of the title compound, C16H13N3O3S, shows that the two independent zwitterions in the asymmetric unit are approximately planar. Intramolecular N—H...O hydrogen bonds occur and the aromatic rings have a trans configuration with respect to the azo double bond. In the crystal, the molecules are linked via N—H...O hydrogen bonds and π–π stacking, forming a three-dimensional supramolecular network, the π–π stacking interactions between adjacent benzene and naphthalene rings having centroid-to-centroid distances of 3.764 (3) and 3.775 (3) Å.

Background and Objectives: Many industrial effluent plants contain amounts of hard biodegradable compounds such as β-naphthol which can be removed by conventional treatment systems. The objective of this research is to treat wastewater containing naphthalene by nano titanium oxide coated on activated carbon. Materials and Methods: Photocatalytic experiments were carried out for different concentrations of β-naphthol using time and pH as dependent factors. Nano TiO2 coated on activated carbone in one liter batch reactor and the resultants compounds concentration were measured in a photocatalytic reactor with UV-C of 12 Watt. Results: The experimental results indicated that UV/ nano TiO2 coated on activated carbone removed 92% of β-naphthol with concentrations of 100 mg/L within an overall elapsed time of three hours. β-naphthol total removal with concenteration of 25 mg/L was observed in two hours.Conclusions: UV/ nano TiO2 process is very fast and effective method for removal of β-naphthol and pH 11 was indicated as the optimum pH.

A novel and efficient procedure for the synthesis of pyrano[4,3- b]chromene derivatives via three-component condensation reaction of benzyl alcohol, β-naphthol, and 4-hydroxycoumarin using a catalytical amount of cerium(IV) ammonium nitrate (CAN) and a reusable ionic liquid as a catalyst at room temperature is presented. The method provides several advantages such as simple work-up, environmental friendliness and shorter reaction time along with high yields. All synthesized compounds were elucidated by comparison with authentic samples, IR, H, and C NMR spectroscopy, and elemental analysis. [ABSTRACT FROM AUTHOR]

A simple and new colorimetric method was developed for the estimation of emtricitabine. The proposed colorimetric method is based on the diazotisation of amine group present in emtricitabine, followed by colour complex formation using β-naphthol reagent. Parameters affecting the reaction were studied and conditions were optimized. The absorption maximum for the colour complex was observed at 559 nm. Linearity was obtained in the concentration range of 100-500 μg/ml for emtricitabine colour complex. The developed method was optimised and validated. The method was successfully applied for the estimation of emtricitabine in bulk and in tablets. This is the first method reported for colorimetric estimation of emtricitabine. [ABSTRACT FROM AUTHOR]

A new series of pyrazolone based azo acid dyes (3a-g) has been synthesized starting from 1-( p-sul-phophenyl)-3-methyl-5-pyrazolone (1). The synthetic methodology included the nitrosation of p-sulphophenyl methyl pyrazolone followed by reduction, diazotization and coupling with Naphthol AS derivatives (2a-f), in alkaline medium to yield different acid dyes. Multichromic metal complexes of these dyes (5a-f, 6a-f and 7a-f) with 3d transition metals Chromium, Iron and Copper were also synthesized. The structures of all of newly synthesized compounds were confirmed by analytical data and spectroscopic techniques. The synthesized dyes were applied on leather to assess their light fastness, wash fastness and rubbing fastness and were shown to exhibit high values of 4-5 for majority of dyes. [ABSTRACT FROM AUTHOR]

In order to develop SiC/SiC ceramic matrix composites with a low porosity, liquid silicon infiltration (LSI) was chosen as a technique, characterized by short processing times. To create the matrix, a tailored phenolic resin containing ß-naphthol units was synthesized and infiltrated in wound fiber preforms, thermally cured, pyrolysed and siliconized. The aim is to obtain a high carbon yield during pyrolysis and to create a dense carbon foam between the SiC fibers. Instead of a classic liquid silicon infiltration via capillary forces through a carbon block-like microstructure, this foam promotes a softer infiltration with less fiber degradation and a maximized carbon conversion to near stoichiometric SiC. To protect the SiC fibers from an attack of the liquid silicon and to simultaneously provide a weak fiber matrix bonding, a BN x /SiN x fiber coating was chosen. The coating was applied by means of low-pressure chemical vapor deposition (LPCVD) using gaseous chlorine free precursors. [ABSTRACT FROM AUTHOR]

In this research, nano-silica-bonded 3- n-propyl-1-sulfonic acid imidazolium chloride {nano-SB-[PSIM]Cl} as a new and efficient Brønsted acidic ionic liquid supported on silica has been synthesized, and characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric, differential thermal gravimetric, X-ray diffraction, and energy-dispersive X-ray spectroscopy spectra. The presented silica-supported ionic liquid has been applied as a highly effective, heterogeneous, easy regenerable, and reusable catalytic system for the solvent-free condensation of arylaldehydes with β-naphthol and alkyl carbamates leading to α-carbamatoalkyl-β-naphthols. Once the nanocatalyst was regenerated and reused, no significant loss of its activity was observed. Graphical Abstract: Design and characterization of nano-silica-bonded 3- n-propyl-1-sulfonic acid imidazolium chloride {nano-SB-[PSIM]Cl} as a novel, heterogeneous and reusable catalyst for the condensation of arylaldehydes with β-naphthol and alkyl carbamates.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

To improve the sensitivity of capillary electrophoresis, field-amplified sample injection (FASI) was developed to determine bisphenol A (BPA), α-naphthol ( α-NAP) and β-naphthol ( β-NAP) in drinks and lake water. Parameters (sample matrix, concentration of NaCl, water plug length, sample injection time and voltage) affecting FASI have been systematically investigated. Under optimum conditions, the sensitivity was improved 17.1-, 15.8- and 9.9-fold for BPA, α-NAP and β-NAP, respectively. The detection limits of BPA, α-NAP and β-NAP were 0.071, 0.038 and 0.081 μg mL and the proposed method has been successfully applied to detect BPA, α-NAP and β-NAP in drinks and lake water with recoveries of 82.0-109.3 %. [ABSTRACT FROM AUTHOR]