Hantzsch Reaction Research Articles

Attaching azoles to Hantzsch 1,4-dihydropyridines: Synthesis, theoretical investigation of nonlinear optical properties, antimicrobial evaluation and molecular docking studies

In the present study, we designed three novel compounds via the combination of two precious nitrogen-containing scaffolds; 1,4-dihydropyridine (DHP) and azole, in the same molecule. To synthesize the title compounds, initially, azolyl benzaldehydes were obtained through the nucleophilic aromatic substitution reaction of 4-fluorobenzaldehyde with pyrazole, imidazole or 1,2,4-triazole. Subsequently, an unsymmetrical Hantzsch reaction was applied to achieve DHP scaffold, thus the target molecules. After structural characterization, the effects of various azole rings on optical and non-linear optical (NLO) properties were investigated by computational methods. Band gaps, chemical hardness/softness, dipole moments, average polarizability, first hyperpolarizability values were computed for the target compounds at the CAM-B3LYP/6-31++G(d,p) level of theory. The comparable results confirmed the potential of DHP-azole hybrids to be utilized in NLO devices. The title molecules were further tested for their antibacterial and antifungal activities following the evaluation of their drug likeness properties. The compounds containing imidazole or triazole rings represented better antifungal properties than antibacterial activities. Molecular docking studies were performed in the catalytic site of lanosterol 14α-demethylase, CYP51, from Candida albicans to explain the obtained biological results and suggest molecular modifications to endow this class of molecules with improved antifungal effects.

New green perspective to dihydropyridines synthesis utilizing modified heteropoly acid catalysts

The classical Hantzsch reaction is a simple and utmost efficient protocol for the synthesis of biologically and pharmacologically important 1,4-dihydropyridine derivatives. The present study deals with the utilization of modified heteropoly acid (HPA) catalysts (5 wt% WOx-FeP and 5 wt% MoOx-FeP) in the synthesis of novel Hantzsch 1,4-dihydropyridines, which contains diphenylsulfone moiety via one-pot synthesis strategy under ultrasound irradiation. The developed protocol is simple and green procedure for the synthesis of 1,4-dihydropyridines and is applicable to synthesize different 1,4-dihydropyridine derivatives. The synthesized HPA catalysts offered a sustainable methodology to produce excellent products yields (88–92%) of 1,4-dihydropyridine derivatives. The catalysts were characterized by XRD, Raman, FT-IR, DRUV-vis, XPS, H2-TPR, N2-physisorption and acidity measurements. The HPA supported iron phosphate nanotubes (FeP) catalysts offered enhanced the catalytic performance through the improved Lewis acid site density, redox properties and surface area, compared to the parent phosphomolybdic and phosphotungstic acids. Moreover, the synthesized catalysts can be easily separated from reaction system and reused for six times efficiently without significant loss of activity.

A derivatization and microextraction procedure with organic phase solidification on a paper template: Spectrofluorometric determination of formaldehyde in milk

A derivatization and air-assisted dispersive liquid-liquid microextraction procedure with organic phase solidification on a paper template was developed for the first time. The procedure was used for the spectrofluorometric determination of formaldehyde in milk samples. The Hantzsch reaction of formaldehyde with acetylacetone in the presence of ammonia to form a derivative (3,5-diacetyl-1,4-dihydrolutidine) was implemented for the microextraction and detection of analyte. Thymol was investigated as the extraction solvent for the air-assisted dispersive liquid-liquid microextraction for the first time. In the developed procedure, molten thymol was added to the thermostated aqueous sample solution containing reagents for formaldehyde derivatization, and cloudy solution of fine thymol droplets was formed by air bubbling. After separation of phases the liquid extract phase was withdrawn with a dispenser and distributed on the black paper template in a thin layer to be solidified. The solidified extract phase on the template was inserted to a sample holder of a spectrofluorometer and fluorescence intensity was measured without using cuvettes. Under optimal experimental conditions the linear detection range was found to be 45–500 µg L−1 with LOD calculated from a blank test, based on 3σ, 15 µg L−1. The developed procedure does not require the dilution of the solid extract phase in organic solvent to be introduced in an analytical instrumentation and the use of cuvettes for spectrofluorometric detection.

Comparison of formaldehyde measurements by Hantzsch, CRDS and DOAS in the SAPHIR chamber

Abstract. Three instruments that use different techniques to measure gaseous formaldehyde (HCHO) concentrations were compared in experiments in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich. One instrument (AL4021, Aero-Laser GmbH) detects HCHO using the wet-chemical Hantzsch reaction (for efficient gas-phase stripping), chemical conversion and fluorescence measurement. An internal HCHO permeation source allows for daily calibrations. This instrument was characterized by sulfuric acid titration (overall accuracy 8.6 %) and yields measurements with a time resolution of 90 s and a limit of detection (3σ) of 0.3 ppbv. In addition, a new commercial instrument that makes use of cavity ring-down spectroscopy (CRDS) determined the concentrations of HCHO, water vapour, and methane (G2307, Picarro, Inc.). Its limit of detection (3σ) is specified as 0.3 ppbv for an integration time of 300 s, and its accuracy is limited by the drift of the zero signal (manufacturer specification 1.5 ppbv). A custom-built high-resolution laser differential optical absorption spectroscopy (DOAS) instrument provided HCHO measurements with a limit of detection (3σ) of 0.9 ppbv and an accuracy of 7 %​​​​​​​ using an optical multiple reflection cell. The measurements were conducted from June to December 2019 in experiments in which either ambient air flowed through the chamber or the photochemical degradation of organic compounds in synthetic air was investigated. Measured HCHO concentrations were up to 8 ppbv. Various mixtures of organic compounds, water vapour, nitrogen oxides and ozone were present in these experiments. Results demonstrate the need to correct the baseline in measurements performed by the Hantzsch instrument to compensate for drifting background signals. Corrections were equivalent to HCHO mixing ratios in the range of 0.5–1.5 ppbv. The baseline of the CRDS instrument showed a linear dependence on the water vapour mixing ratio with a slope of (-11.20±1.60) ppbv %−1 below and (-0.72±0.08) ppbv %−1 above a water vapour mixing ratio of 0.2 %. In addition, the intercepts of these linear relationships drifted within the specification of the instrument (1.5 ppbv) over time but appeared to be equal for all water mixing ratios. Regular zero measurements are needed to account for the changes in the instrument zero. After correcting for the baselines of measurements by the Hantzsch and the CRDS instruments, linear regression analysis of measurements from all three instruments in experiments with ambient air indicated good agreement, with slopes of between 0.98 and 1.08 and negligible intercepts (linear correlation coefficients R2>0.96). The new small CRDS instrument measures HCHO with good precision and is accurate if the instrument zero is taken into account. Therefore, it can provide measurements with similar accuracy to the DOAS instrument but with slightly reduced precision compared to the Hantzsch instrument.

Synthesis and Characterization of Pyridine-Grafted Copolymers of Acrylic Acid-Styrene Derivatives for Antimicrobial and Fluorescence Applications.

The goal of the present study was to copolymerize 3-(4-acetylphenylcarbamoyl) acrylic acid and styrene using azo-bis-isobutyronitrile (AIBN) as a catalyst. The resulting copolymers exhibited number average molecular weights (Mn) of 3.73–5.23 × 104 g/mol with a variable polydispersity (PDI = 2.3–3.8). The amide group of the PMA/PSA polymer was used for grafting poly (-styrene-maleic acid substituted aromatic 2-aminopyridine) by the Hantzsch reaction using a substituted aromatic aldehyde, malononitrile, and ammonium acetate. The polymer can emit strong blue fluorescence (λ = 510 nm) and its thermal stability and solubility were enhanced by polymer grafting. Moreover, the polymer showed the fluorescence spectra of the copolymer had a strong, broad emission band between 300 to 550 nm (maximum wavelength 538 nm) under excitation at 293 nm. The Hantzsch reaction yields an interesting class of nitrogen-based heterocycles that combine with a synthetic strategy for synthesis of grafted co-polymer pyridine-styrene derivatives. The as-prepared pyridine-based polymer compounds were screened against Gram-positive and Gram-negative bacteria, where a maximum inhibition zone toward all four types of bacteria was observed, including specific antifungal activity. Herein, a series of pyridine compounds were synthesized that showed enhanced fluorescent properties and antimicrobial properties due to their unique structure and ability to form polymer assemblies.

An innovational validated spectrofluorimetric technique for determination of 6-Aminocaproic acid in pure form and its tablet: Application to spiked human plasma and urine

An innovative and sensitive spectrofluorimetric method has been developed for determination of 6-aminocaproic acid (ACA) in its pure form and its laboratory prepared tablets. The aim of this method is the reaction of ethyl acetoacetate and formaldehyde with the primary amino group presented in ACA as aimed in the Hantzsch reaction, this reaction resulted in formation of a yellow fluorescent dihydropyridine derivative that can be easily detected spectrofluorimetrically at 438 nm (excitation at 358 nm). At the optimum conditions of the reaction, the linear range was found to be (0.7–3.5 µg\\mL) with limit of detection is 0.231 µg\\mL and limit of quantitation is 0.700 µg\\mL. The proposed method used for detection of ACA laboratory prepared tablets with average percentage 100.721 ± 0.701% without any interference from any excipients. This method used for in vitro determination of ACA in spiked human plasma with a percent mean recovery 99.874 ± 1.416%. In addition, the developed method used for determination of ACA in spiked human urine with percent mean recovery 100.314 ± 1.793%.

Solar energy as a renewable energy source for preparative-scale as well as solvent and catalyst-free Hantzsch reaction

A well-known Hantzsch reaction for the synthesis of 1,4-dihydropyridine was performed in an eco-friendly manner using concentrated solar radiation. Solvent and catalyst-free approach with excellent yield is the key feature. The present mild, green, and energy-efficient method tolerates the various substrates. Multi-gram scale up (50 mmol), shorter reaction time, simple work-up procedure and high atom efficiency are the added advantages of this reported protocol.

Application of Hantzsch reaction for sensitive determination of eflornithine in cream, plasma and urine samples.

Eflornithine (EFN) is an anti-Trypanosoma brucei agent for the medication of sleeping sickness and widely distributed for the treatment of hirsutism (unwanted facial hair in women). The presented work demonstrates a comprehensive analytical approach for the spectrofluorometric determination of EFN in commercial cream samples and various biological samples. The proposed method is based on the formation of a highly yellow–green fluorescence dihydropyridine derivative after the interaction between EFN and acetylacetone/formaldehyde reagent in a slightly acidic medium. Furthermore, the optimal variables such as reagent volumes, pH of the medium, heating time, buffer volume, heating temperature and diluting solvent were carefully selected to achieve the maximum fluorescence activity. The fluorescence activity for the formed derivative was measured at λemission = 477 nm after λexcitation = 418 nm. Concerning linearity, accuracy, sensitivity, precision and robustness, the presented method was validated and verified according to ICH guidelines. Moreover, the proposed work offered a selective determination for EFN in various brands of pharmaceutical cream without any interference from excipients. Eventually, the current approach was assured to be successful in the estimation of EFN in urine and plasma samples with acceptable recovery results.

Retraction of "Enantioselective Organocatalytic Hantzsch Synthesis of Polyhydroquinolines".

The following changes were made to the revised Supporting Information document submitted with this correction: (1) All data referring to compound 4o has been removed. (2) HPLC traces for 4a, 4d, 4h, and 4n have been replaced with less ambiguous choices, pp 43−47. (3) Clarification of the method to confirm peak identities is now included, p 48. (4) Confirmation of peak identities is now included for compounds 4a, 4d, 4h, 4k, 4l, and 4n, pp 48−50. (5) Missing retention times for compounds 4a and 4g have been added on p 42. (6) H NMR peaks have been added for compounds 4k and 4j. These were missing in the original document, p 5. (7) The new Supplemental Figure 1 has been added (p 2), which shows that the Hantzsch reaction to produce compound 4b does not proceed in the absence of catalyst. We previously neglected to include this important data. This material is available free of charge via the Internet at http://pubs.acs.org.

The first spectrofluorimetric approach for quantification of colistin sulfate and its prodrug colistimethate sodium in pharmaceutical dosage form and human plasma.

A new, accurate, nonextractive, and sensitive fluorimetric approach was proposed and validated for the first time estimation of colistin sulfate and its inactive prodrug colistimethate sodium in its bulk form, pharmaceutical formulations, and human plasma. The approach relied on condensation between acetylacetone/formaldehyde and the primary amino moiety of nonfluorescent colistin in Teorell and Stenhagen buffer (pH 2.8) by the Hantzsch reaction to form a highly fluorescent dihydropyridine derivative. The fluorescent product was measured at 460 nm (λex = 402 nm). A plot of relative fluorescence intensity (RFI) versus concentration was rectilinear over the range 200-4000 ng ml-1 with excellent correlation (r) and determination (r2 ) coefficients of 0.9999 and 0.9998, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) were 40.91 and 123.99 ng ml-1 , respectively. The present procedure was useful for determination of colistin sulfate either in powder form for suspension or in its parenteral prodrug colistimethate sodium in vial formulation. The investigated approach was applied for in vitro quantification of this drug in spiked human plasma, with a per cent mean recovery of 98.24 ± 1.34. The proposed method is reliable, selective, and does not require tedious sample pretreatment steps, expensive instrumentation, or harmful reagents, all of which make it ideally suited for use in quality control laboratories.

Fe3O4@cysteine nanocomposite: An efficient and reusable catalyst for the facile, green, one-pot synthesis of 1,4-dihydropyridine via Hantzsch reaction

• Fe 3 O 4 @cysteine magnetic nano particle were prepared. • The catalyst used for Hantzsch reactions for preparing 1, 4-dihydropyridine derivatives with high efficiencies. • Key advantages are high yields, short reaction time and simple work-up procedure. • The nanomagnetic catalyst could be recovered from solution with an external magnet at once, allowing undemanding recovery and reuse. • The catalyst was reused for five times with no considerable decrease in catalytic activity. An efficient, clean, and environmentally friendly three-component/one-pot protocol was developed for the synthesis of 1,4-dihydropyridines using Hantzsch reaction by a reaction of aldehydes, ethyl acetoacetate, and ammonium carbonate using Fe 3 O 4 @cysteine magnetic nanoparticles as a catalyst. This strategy provides several advantages such as good to high yields (79 to 96%), short reaction time, a simple work-up procedure, less tedious workup, mild condition, avoidance of hazardous organic solvents, minimal waste, recyclability of catalyst, ability to tolerate a variety of functional groups which gives economical as well as ecological rewards and no chromatographic purification. The present protocol takes advantage of the fact that water, a green solvent is used in combination with Fe 3 O 4 @cysteine nanoparticles as a catalyst which can be easily recovered magnetically and reused for further runs. Also, this efficient and practical protocol proceeded smoothly in gram scale at lower catalytic concentration. An efficient, clean, and environmentally friendly three-component/one-pot protocol was developed for the synthesis of 1,4-dihydropyridines using Hantzsch reaction by a reaction of aldehydes, ethyl acetoacetate, and ammonium carbonate using Fe 3 O 4 @cysteine magnetic nanoparticles as a catalyst. The advantages of methods are shorter reaction time, milder conditions, easy work-up and purification of products by non-chromatographic methods.

One‐Pot Synthesis of Hantzsch 1,4‐Dihydropyridines by a Series of Iron Oxide Nanoparticles: Putative Synthetic TRPV6 Calcium Channel Blockers

AbstractVarious spinel iron oxide nanoparticles (MFe2O4, M: Ca, Co, Cu, Fe, Hg, Mg, Mn, Ni, Sn and Zn) have been prepared using a single step coprecipitation method. Nanoparticles were characterized using XRD, FESEM, FT‐IR and UV‐Vis diffuse‐reflectance spectroscopy. The catalytic activities of the synthesized nanoparticles in Hantzsch reaction have been studied. HgFe2O4 NPs exhibits the highest catalytic activity than others. The structural properties of synthesized 1,4‐dihydropyridine were characterized by mass spectrometry, FT‐IR and 1H‐ and 13C‐NMR. Finally, the in silico molecular simulations for screening of blocking ability of synthesized 1,4‐dihydropyridine against various TRPV6 proteins were performed. These studies revealed that examined 1,4‐dihydropyridines are promising TRPV6 calcium channel blockers. As a result, molecular modeling confirmed that synthesized 1,4‐DHPs are docked on the pore region of the examined TRPV6 channels.

Synthesis, characterization and cytotoxicity evaluation of a novel magnetic nanocomposite with iron oxide deposited on cellulose nanofibers with nickel (Fe3O4@NFC@ONSM-Ni).

A heterogeneous, magnetically recoverable nanocomposite, Fe3O4@NFC@ONSM-Ni(ii) was prepared by immobilization of a novel Ni(ii) Schiff base complex on Fe3O4@NFC nanoparticles followed by treatment with melamine. This trinuclear catalyst has been characterized using several analytical techniques including FT-IR, TEM, Fe-SEM, EDX, DLS, ICP, TGA, VSM, and XRD. It was used as an efficient catalyst for one-pot solvent-free synthesis of 1,4-dihydropyridine and poly-hydro quinoline derivatives through Hantzsch reaction. This catalyst showed remarkable advantage over previously reported catalysts due to suitable conditions, short reaction time, high efficiency and lower catalyst load and timely recovery of the magnetic catalyst. Moreover, the effects of Fe3O4@NFC@ONSM-Ni(ii) nanoparticles on the in vitro proliferation of human leukemia cell line (k562) and human breast cancer cells (MDA-MB-231) were investigated. The results of MTT and Hochest assays suggested that the nanoparticles could effectively inhibit the proliferation of these cancer cells in a time- and concentration-dependent manner.

A Review: Alternative Methods of Preparing 1, 4- Dihydropyridine Derivatives by Hantzsch Reaction

A Review: Alternative Methods of Preparing 1, 4- Dihydropyridine Derivatives by Hantzsch Reaction

The Hantzsch reaction for nitrogen-13 PET: preparation of [13N]nifedipine and derivatives.

Nitrogen-13 is an attractive but under-used PET radionuclide for labelling molecules of biological and pharmaceutical interest, complementing other PET radionuclides. Its short half-life (t1/2 = 9.97 min) imposes synthetic challenges, but we have expanded the hitherto limited pool of 13N labelling strategies and tracers by adapting the multicomponent Hantzsch condensation reaction to prepare a library of 13N-labelled 1,4-dihydropyridines from [13N]ammonia, including the widely-used drug nifedipine. This represents a key advance in 13N PET radiochemistry, and will serve to underpin the renewed interest in clinical opportunities offered by short-lived PET tracers.

An Efficient Method for The Synthesis of Dihydropyridine by Hantzsch Reaction with Fe/SiO2 Nano Heterogeneous Catalysts

An efficient method for the synthesis of dihydropyridines (DHPs) by Hantzsch reaction with Fe/SiO2 heterogeneous catalysts was developed. The Fe/SiO2 catalysts was prepared by impregnation method. The catalysts were characterized by IR and SEM instruments. The SEM results indicated that Fe/SiO2 nano spheres were formed. The reaction procedure involved reaction of aldehyde, ethyl acetoacetate (EAA), ammonium acetate (NH4OAc) and ethanol under reflux. The study was focused on optimizing reactions conditions: Standardization of catalyst, substrate of study and solvent study. In order to identify the best active catalysts, five different ratios of catalyst were synthesized and evaluated for the title reaction under similar conditions. To standardize the active catalysts, different temperature conditions (i.e. room temperature, 60 ºC and 80 ºC) as well as catalysts amounts were evaluated. Under these established conditions, 2.5% Fe/SiO2 was the best active catalysts that resulted. Benzaldehyde and p-anisaldehyde were used to study the effect of having various substrates on the conversion and reaction time, especially the substituted aldehydes. The best results were obtained by reacting p-anisaldehyde with EAA, NH4OAc and ethanol at 60 ºC with 0.3 grams of 2.5% Fe/SiO2 heterogeneous catalysts. Thin Layer Chromatography (TLC) monitoring of the reaction mixture showed no selectivity at high temperatures (80 ºC) with 15% Fe/SiO2. Standardization of solvent study was executed with two solvents, ethanol and acetonitrile. The product dihydropyridines were analyzed using gas chromatography-mass spectrometry (GC-MS). The melting points of the products were compared with authentic samples reported in the literature. Hence, the Fe/SiO2 catalysts is eco-friendly and economically developed for the title reaction. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Green synthesis, characterization and applications of silver nanoparticle mediated by the aqueous extract of red onion peel

This manuscript describes the reuse of biowaste for the biosynthesis of silver nanoparticles (AgNPs) and their applications. In particular, we hypothesized that the phytochemicals in the onion peels could act as reductant for silver nanoparticles syntheses. AgNO3 solution (1mmol) was added dropwise to an aqueous solution of onion peel extract in 3:7 ratio. The reaction mixture was subjected to heating at 90°C for about 30min. During the synthesis of the AgNPs, the change of the colour of solution was observed. The AgNPs solution was centrifuged to obtain the two layers, which consists of clear solution and solid layers at 12000rpm for 30min. The precipitate was filtered and was re-dispersed in deionised water (25mL). The solution was centrifuged again to obtain the purified AgNPs. Subsequently, this solution was freeze dried for 48h to afford the powdered AgNPs. In this work, the structure of the AgNPs were synthesized in spherical shape, with an average size of 12.5nm observed in the Transmission electron microscopy (TEM) analysis. For catalytic application, the synthesized AgNPs could be applied as green catalyst to promote Knoevenagel and Hantzsch reactions. In most cases, the desired products were obtained in satisfactory yields. In addition, the AgNPs were found to be recyclable for the subsequent reactions. After five successive runs, the average isolated yields for both transformations were recorded to be 91% (Knoevenagel condensation) and 94% (Hantzsch reaction), which indicated that the existing AgNPs could apply as green catalyst in the field of organic synthesis. Furthermore, the AgNPs also showed satisfactory result in antioxidant activity. The current results indicate that the AgNPs can act as alternative antioxidant agent and green catalyst in mediating organic transformations.

Synthesis, Docking and Anti-cancerous Activity of Some Novel Thiazole Derivatives of Biological Interest

Objectives: Heterocyclic compounds are enormously widespread in nature and have attracted research interest because of their pharmaceutical and biological properties. Amongst the heterocyclic rings, the thiazoles are the most important building blocks in today’s drug discovery and are found to have extensive biological activities against different types of diseases. Many potent anti-cancerous drugs like Tiazofurin are having 1,3 thiazole as an active ring structure and based on this theory, a new series of 2, 4 di substituted 1,3 thiazole derivatives were synthesized. Methods: First 2-amino-4-substituted phenyl thiazoles were synthesized by adapting a well-known Hantzsch reaction and subsequently 2-amino substituted derivatives were synthesized using various aryl aldehydes by following established Schiff’s reaction. The synthesized compounds were confirmed by TLC, IR, HNMR, CNMR and Mass Spectral Analysis. Then all the synthesized compounds were docked to RAS p21 receptor using PATCH DOCK Software to study their anti-cancerous activity. Then the compounds were screened for cancer cell line studies. Results: All the synthesized compounds exhibited some degree of anti-cancerous activity both in docking studies and in vitro anti-cancerous cell line studies. Conclusion: Amongst all the 16 synthesized, most compounds showed moderate to good anti-cancerous activity and the compounds S3P1c, S3P2c, S3P2d, S3P3a and S3P4d have shown the best activity.

One-pot multicomponent green Hantzsch synthesis of 1,2-dihydropyridine derivatives with antiproliferative activity.

A rapid route for obtaining unsymmetrical 1,2-dihydropyridines (1,2-DHPs) as opposed to 1,4-dihydropyridines (1,4-DHPs) has been achieved via a one-pot multicomponent Hantzsch reaction. A benign protocol has been developed for the preparation of various 1,2-dihydropyridine derivatives using heterogenized phosphotungstic acid on alumina support (40 wt %). High yields of over 75% have been accomplished in just 2–3.5 h after screening several heterogeneous catalysts and investigating the optimal reaction conditions. The catalyst chosen has passed the heterogeneity test and was shown to have the potential of being reused for up to 8 consecutive cycles before having a significant loss in activity. In addition, aromatic aldehydes gave the aforementioned regioisomer while the classical 1,4-DHPs were obtained when carrying out the reaction using aliphatic aldehydes. The preliminary study of the antiproliferative activity against human solid tumor cells demonstrated that 1,2-DHPs could inhibit cancer cell growth in the low micromolar range.

1,4 Butanesultone Functionalized Graphitic Carbon Nitride: Efficient Catalysts for the One-Pot Synthesis of 1,4-Dihydropyridine and Polyhydroquinoline Derivative through Hantzsch Reaction

In this research, covalently linked sulfonic acid (SO3H) modified g-C3N4 nanosheet (CNNs) catalysts was prepared. For this purpose, graphitic carbon nitride nanosheets (CNNs) were successfully synthesized. By the reaction of synthesized CNNs with 1,4-butane-sultone, CNNs-Bu-SO3H organocatalyst was produced. The synthesized organocatalyst was characterized by FTIR, EDS, XRD, FESEM, and TGA analysis. The catalytic efficiency of the CNNs-Bu–SO3H was explored for the synthesis of 1,4-dihydropyridine and polyhydroquinoline derivatives. The synthesized organocatalyst exhibits good thermal stability, high acidity and could be used up to five reaction cycles without a noticeable decrease in catalytic activity.