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The generation of a large quantity of waste coal fly ash (CFA) via coal combustion process during power generation is of major concern as disposal of such huge quantity of fly ash causes serious threats to the environment. There is an exigent need to find out the proper solution for its disposal/utilization to reduce its harmful effects. The composition of waste coal fly ash mostly consists of silica and alumina. Hence, the researchers are tempted to utilize waste coal fly ash as a starting ingredient to make value-added materials like zeolites. It is anticipated that such research efforts will act as a valuable aid to reduce the disposal cost of fly ash and ultimately reduce harmful effects of fly ash to the environment. In this review, various synthesis methods to synthesize different types of zeolites from CFA, such as Zeolite-A, Zeolite-X and Zeolite-P, have been summarized and their potential for various applications such as sorption and catalysis has been explored.

In the present work, a hybrid catalytic material of the class of tetravalent metal acid (TMA) salts has been synthesized by the sol–gel method, wherein solution of titanium tetrachloride is allowed to react with claw-type organic phosphonic acid, amino tris methylenephosphonic acid (ATMP) under appropriate reaction conditions of pH, temperature, time and ageing period. The resultant hybrid material (Ti-ATMP) was found to possess proton donating behaviour, and hence it was thought of interest to use it as solid acid catalyst to perform catalysed esterification reaction of biomass-derived levulinic acid with n-butanol to synthesize n-butyl levulinate. Various process parameters such as catalyst concentration % (X1), LA:n–butanol molar ratio (X2) and reaction time (min) (X3) were optimized by response surface methodology (RSM), using the Box–Behnken Design (BBD). Analysis of variance was performed in order to check the suitability of the quadratic model. The catalytic reusability study has been performed in order to have an idea about feasibility of its reuse. Ti- ATMP catalyst was found efficient and promising with satisfactory yields and excellent reusability. The results clearly indicate its potentiality as solid acid catalyst to catalyse other organic transformations.

The present work is focusing on the improvement of catalytic characteristics of zeolite. In the present endeavor, zeolite H-BEA has been modified using sol-gel route by making use of tetradecyltrimethyl ammonium bromide (TTAB) surfactant as a structure directing agent. The synthesized mesozeolite was characterized by SEM, HRTEM, 29Si and 27A1 MAS-NMR, small and wide-angle XRD, FT-IR, TGA, NH3-TPD, ICP-OES and BET surface area analysis. The synthesized material was found to exhibit mesoporosity along with microporosity of parent H-BEA. The utility of modified H-BEA as heterogeneous catalyst was demonstrated in the production of value added chemical, n-butyl levulinate from biomass derived feedstock, levulinic acid (LA) via esterification reaction. n-butyl levulinate is one of the significant industrial chemical and has wide use as plasticizing agent, solvent and odorous substance. Various process variables such as molar ratio (LA to n–butanol), catalyst concentration (%) and reaction time (h) were optimized by response surface methodology (RSM), using the Box–Behnken Design (BBD). Analysis of variance (ANOVA) has been performed to investigate the suitability and significance of the quadratic model.

The present work focuses on the utilization of waste biomass for the improvement of key catalytic properties of conventional zeolite H-BEA. In the present endeavor, zeolite H-BEA has been modified using cetyltrimethyl ammonium bromide (CTAB) and rice husk (a waste biomass resource), via desilication post synthetic route, which is not reported so far. The synthesized mesoporous zeolite H-BEA catalysts have been characterized by various characterization techniques such as, SEM, 27Al and 29Si MAS-NMR, wide and low angle XRD, ICP-OES, FT-IR, TGA, NH3-TPD and BET surface area. The resultant mesoporous zeolite materials (MCCK and MCRK) exhibited bimodal porosity as well as improved physicochemical properties, and the utility of these modified zeolites as heterogeneous catalysts has been demonstrated in the production of n-butyl levulinate via levulinic acid (LA) esterification. The catalytic material, which has been modified using CTAB and rice husk, is found to exhibit better catalytic activity towards the synthesis of n-butyl levulinate (95.6%) as compared to other zeolite counterparts under the optimised reaction conditions, which is attributed to its enhanced surface area and lower Si/Al ratio as compared to other catalysts under study.

In view of the growing threat of climate change, there is a need to put intense research efforts to reverse global warming effects. Use of inexpensive and abundantly available lignocellulose as a carbon source for reducing societal dependence on fossil fuels and anthropogenic CO2 emissions is vital in the current scenario. There is a need to emphasize on gradual shift from petroleum-based technologies toward renewable feedstock-based technologies for value-added chemical synthesis. Catalytic conversion of low-cost biomass into diversified industrially significant platform chemicals is of great research interest. Lignocellulose-derived levulinic acid (LA) is increasingly gaining attention among industrialists and academicians owing to its useful properties and potential industrial applications. Notable chemicals that are synthesized/derived from LA include levulinate esters, γ-valerolactone, acrylic acid, 1,4-pentanediol, β-acetylacrylic acid, α-angelica lactone, 2-methyltetrahydrofuran, δ-aminolevulinic acid, etc. Among these, levulinate esters find useful applications as plasticizing agents, fragrance chemicals, solvents, intermediates in organic process industries, oxygenate additives in fuels, etc. Levulinate esters are generally obtained by esterification reaction in the presence of suitable acid catalysts, either in homogeneous (liquid acid) and heterogeneous (solid acid) medium. The solid acid catalysts are mostly favored over liquid acids to avoid issues related to handling, separation, regeneration, and disposal due to the corrosive and toxic nature of liquid acids. This chapter presents a brief account on several value-added chemicals that are derived from LA and discussion on homogeneously and heterogeneously catalyzed esterification reaction of LA to yield various valuable levulinate esters. Zeolite-/mesozeolite-catalyzed esterification of LA to synthesize n-butyl levulinate and pentyl levulinate has been covered in detail. Zeolites as a heterogeneous catalyst are important in the development of cleaner technologies. This effort will serve as an aid for industrialists and academicians who are working in the area of conceptualizing LA biorefineries.

A new surfactant supported cation exchanger and adsorbent named, polyoxyethylene octyl phenyl ether supported thorium(IV) phosphate (TX-100ThP) has been reported along with its synthesis, physico-chemical characterization such as scanning electron microscopy, X-ray diffraction, thermogravimetric analysis–differential thermal analysis and Fourier transform infra-red study. Following the characterization, the formed product has been tested for its efficiency in ion exchange chemistry and in analytical chemistry. For the testing, adsorption of alkaline earths—Mg2+, Ca2+, Sr2+ and Ba2+ and transition metal ions such as Fe3+, Mn2+, Ni2+, Cd2+, Co2+, Cu2+, Hg2+ and Pb2+ have been explored in different acidic media and the results revealed the selectivity of synthesized material towards Hg2+ ions. On that basis, the material has been used to treat the binary laboratory-made samples, exploring the environmental importance of the cation exchanger in material science.

Propylsulfonic acid functionalized Santa Barbara Amorphous-15 (SBA-15–Pr–SO3H) catalyst has been synthesized using a surface modification of mesoporous SBA-15 via the one-pot co-condensation method. The synthesized SBA-15–Pr–SO3H has been characterized by peculiar characterization techniques such as small- and wide-angle XRD, SEM–EDX, TEM, TG–DTA, acidity, FT-IR, Py-FT-IR and BET surface area analysis. The catalytic activity of synthesized catalyst has been studied towards solvent-free MW irradiation for the green and rapid synthesis of multi-substituted imidazoles, [2,4,5-triphenyl-1(H)-imidazole (tri-imidazole) and 1-benzyl-2,4,5-triphenyl-1H-imidazole (tetra-imidazole)]. The SBA-15–Pr–SO3H catalyst was found to be an efficient and recyclable solid acid catalyst and this solvent-free MW protocol afforded products in good to excellent yields of both, tri and tetra imidazoles (> 95%) within shorter reaction time (3 min) at 600 W as compared to the SBA-15 and other existing protocols. The applicability of this protocol was further explored by conducting the experiments in the presence of varied solvents and substituted aldehydes to generate a library of both, tri- and tetra-imidazole scaffolds. The catalyst was found to be reusable up to several runs without loss of its catalytic activity. This report allows the rapid and scalable access to a variety of multi-substituted imidazoles using SBA-15–Pr–SO3H, as heterogeneous catalyst. SBA-15–Pr–SO3H catalyzed solvent-free MW assisted green synthesis of multi-substituted imidazoles via MCRs.

In the present endeavour, a micro–meso zeolite composite (mesozeolite) material is synthesized from alkali treated microporous ZSM-5 precursor via sol–gel route using cetyltrimethyl ammonium bromide and rice husk, one of the agriculture biomass. Agricultural biomass is increasingly acknowledged as multifunctional materials for various applications based on their characteristics and availability. Mesozeolites possess enhanced physicochemical characteristics (acidity, thermal stability and bimodal porosity) as compared to individual microporous and mesoporous materials. This newly synthesized material has been characterized by several characterization techniques such as, SEM, wide and low angle XRD, FT–IR, TGA, ICP-OES and BET surface area analysis. The utility of the synthesized composite material has been demonstrated as an efficient solid acid catalyst in the synthesis of n-butyl levulinate via levulinic acid esterification. The product, n-butyl levulinate has significant industrial use in the manufacturing of valuable organic products such as odorants, solvents, polymers and plasticizers. The effects of various reaction parameters such as molar ratio, catalyst concentration and reaction time, have been investigated. Higher % yield of n-butyl levulinate is obtained in case of meso-ZSM-5 as compared to its parent counterparts under the optimized reaction conditions, which is attributed to the enhanced surface area and acidity of the composite material.

The present research work deals with the bio-waste valorisation approach for the catalyst development and then its use in the low cost biodiesel production. The sulfonated carbon catalyst, a solid acid is prepared from waste orange peels (WOP) through carbonization followed by sulfonation treatment. WOP is one of the bio-wastes of food industries. The developed catalyst was characterized using elemental, spectral and thermal analysis. Surface area and pore volume is measured using Brunauer, Emmett and Teller (BET) surface area analysis. The synthesized catalyst exhibits 44 m2/g surface area and 1.57 mmol/g acid density. To demonstrate the catalytic performance, the sulfonated carbon catalyst was used to esterify corn acid oil (CAO), a low cost feed stock containing 127.21 mg KOH/g acid value, to generate cost effective biodiesel. 91.68% biodiesel conversion is obtained under optimized conditions using Box-Behnken Design (BBD).

In this paper, a hybrid exchanger, zirconium triethylenetetramine (ZrT), of the class of tetravalent metal acid (TMA) salts, has been synthesized by the sol–gel method. In the present work, an attempt has been to investigate the sorption behavior of lanthanum, cerium, and thorium metal ions towards ZrT exchanger in various electrolytes media with different concentrations. In order to understand the uptake behavior of ZrT, parametric studies, kinetic and thermodynamic studies have been investigated. Distribution studies data revealed the feasibility of binary lanthanide separations using ZrT and show possibility of its promising use as an efficient ion exchanger in the treatment of water containing radioactive metal waste. In general, the decay storage or ion exchange treatment is used for the treatment of aqueous waste generated from the low nuclear power reactor. As per the report (IAEA-TECDOC-654, 1992), such nuclear aqueous waste generated is found acidic in view of used acidic chemicals during the process. The use of ZrT will be effective or in other words, ZrT can be a potential candidate to be used as an ion-exchange material for the treatment of such nuclear aqueous waste, after optimizing the process parameters, in particular maintaining the pH in the range of 4–5.

In the present study, the catalytic activity of various medium (H-ZSM-5) and large pore (H-BEA, H-Y, H-MOR) zeolites were studied as solid acid catalysts. The zeolite H-BEA is found to be an efficient catalyst for the synthesis of 1-benzyl-2,4,5-triphenyl-1H-imidazoles through one-pot, 4-component reaction (4-CR) between benzil, NH4OAc, substituted aromatic aldehydes and benzyl amine. The hydrophobicity, Si/Al ratio and acidic properties of zeolite BEA were well improved by controlled dealumination. The synthesized materials were characterized by various characterization techniques such as XRD, ICP-OES, BET, NH3-TPD, FT-IR, pyridine FT-IR, 27Al and 1H MAS NMR. It has been observed that the dealumination of the parent zeolite H-BEA (12) results in the enhanced strength of Bronsted acidity up to a certain Si/Al ratio which is attributed to the inductive effect of Lewis acidic EFAl species, leading to the higher activity of the zeolite BEA (15) catalyst towards the synthesis of 1-benzyl-2,4,5-triphenyl-1H-imidazoles under thermal solvent-free conditions with good to excellent yields. Using the present catalytic synthetic protocol, diverse tetra-substituted imidazoles, which are among the significant biologically active scaffolds, were synthesized in high yield within a shorter reaction time. The effect of polarity, surface acidity and extra framework Al species of the catalysts has been well demonstrated by means of pyridine FT-IR, and 27Al and 1H MAS NMR. The solvent-free synthetic protocol makes the process environmentally benign and economically viable.

Transesterification of refined cottonseed oil was studied in the presence of silica sulfuric acid as a new heterogeneous solid acid catalyst to overcome the drawbacks of homogeneous alkali and acid catalysts. The effect of various reaction parameters, such as oil to methanol ratio, reaction temperature, reaction time, and catalyst amount, was investigated. The highest methyl ester conversion was obtained at 373 K using 5% catalyst amount and 1:20 methanol ratio within 8 h. Silica sulfuric acid was found to be a promising catalyst for cleaner biodiesel production without tedious post treatments for the product purification.

Cloud point extraction was carried out to remove Coralene red (CR) dye from aqueous solution using tetra ethyl ammonium tetrafluoroborate [TEA(BF4)] ionic liquid as an additive with non-ionic surfactant Triton X-114. The effects of different operating parameters such as concentration of surfactant; IL and dye, time, temperature on extraction of dye has been studied in detail. The extraction of dye was found to be increased with temperature, time, surfactant concentration, and IL concentration. A developed Langmuir isotherm was used to calculate the required feed surfactant concentration along with 0.1 wt % TEA(BF4) IL for the removal capacity of CR dye up to 90%. The effects of temperature and concentration of surfactant on various thermodynamic parameters were observed. The solvent extraction method using hexane as an extracting medium for the recovery of surfactant from the coacervate phase was also examined. © 2015 American Institute of Chemical Engineers Environ Prog, 2015

In the last decade, increasing interest on the use of aqueous micellar solution has been found in the field of separation science. The unique physical and chemical properties of ionic liquids make them most suitable candidates as an additive with nonionic surfactants in cloud point extraction. A surfactant-mediated cloud point extraction process has been adopted for the removal of Coralene red dye using tetraethyl ammonium tetrafluoroborate ionic liquid as an additive with nonionic surfactant Triton X-100. The detailed study on effect of various operating parameters such as temperature, time, concentration of surfactant, dye and IL on extraction of dye has been carried out to find out optimum conditions. The extraction of dye was found to be increased with temperature, time, surfactant concentration and IL concentration. A developed Langmuir isotherm was used to compute the feed surfactant concentration required for the removal of Coralene red dye up to an extraction efficiency of 90 %. The effect of temperature and concentration of surfactant and dye on various thermodynamic parameters was examined, and it was found that the values of ΔG 0 increased with temperature and decreased with surfactant and dye concentration. The values of ΔH 0 and ΔS 0 increased with surfactant concentration and decreased with dye concentration. The developed approach for IL-assisted cloud point extraction has proved to be an efficient and green route for extraction of Coralene red from water sample.

Cloud point extraction (CPE) was adopted for removal of Blue BG dye from aqueous solution using tetraethyl ammonium tetrafluoroborate [TEA(BF4)] ionic liquid (IL) as an additive with non-ionic surfactant Triton X-114 (TX-114). The effect of different operating parameters such as temperature, time, concentration of surfactant; IL and dye on extraction of dye have been studied in detail to find out optimum conditions. The extraction efficiency was found to increase significantly with temperature, time, surfactant concentration and IL concentration. A developed Langmuir isotherm was used to compute the feed surfactant concentration required for the removal of Blue BG dye up to an extraction efficiency of 90%. The effect of temperature and concentration of surfactant on various thermodynamic parameters, like change in Gibbs-free energy (ΔG°), change in enthalpy (ΔH°), and change in entropy (ΔS°) were examined. It was found that ΔG° increased with temperature but decreased with surfactant concentration whereas ΔH° and ΔS° increased with surfactant concentration.

An efficient one pot synthesis of novel ammonium based dicationic ionic liquids (DILs) under microwave (MW) conditions has been carried out. The synthesized DILs are characterized by 1H NMR, 13C NMR, mass spectrometry and elemental analyses. The thermal properties of DILs are studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) methods. The decomposition of synthesized DILs falls between 209 and 266 °C. All synthesized DILs are soluble in polar solvents and insoluble in non polar solvents. The MW irradiation method provides significant quantitative yields and takes less time than conventional method.

Biodiesel synthesis from acid oil (AO) containing high free fatty acids (FFA) over pore expanded sulfonic acid functionalized mesostructured SBA-15 was studied. Reaction parameters affecting the FAME yield were optimized using Taguchi design. 99% FFA conversion was obtained under optimum conditions viz. at 100 °C with 4 wt.% catalyst amount and 1:15 oil to methanol ratio after 8 h. Kinetic study revealed that the reaction followed pseudo first order kinetic law.

A series of iron-exchanged heteropoly tungstate (TPA-Fe) supported on activated carbon produced from pinecone biomass, have been investigated as catalysts for the benzylation reaction. Catalysts were characterized by FT-IR, XRD, Laser Raman, BET surface area, and ammonia TPD analysis. FT-IR, XRD, and Raman data revealed retention of the Keggin ion on activated carbon-supported catalysts. The catalytic activity of these catalysts was evaluated for liquid phase benzylation of anisole with benzyl alcohol. The catalytic activity was significantly dependent on the dispersion of TPA-Fe on activated carbon. The effect of TPA-Fe loading on activated carbon was studied ranging from 40 to 80 wt%. The catalyst with 70 wt% loading of TPA-Fe showed higher benzylation activity, which is related to variation in acidity of the catalysts. Thermal stability and structural properties of the catalysts were studied by treating the catalyst at different calcination temperatures. The benzyl alcohol conversion and selectivity towards benzylated products were also dependent on the anisole to benzyl alcohol molar ratio, reaction temperature, and catalyst concentration/loading. To know the effect of the benzylating agent, the reaction was carried out using benzyl chloride, benzyl alcohol, and dibenzylether. The preferential order for conversion of the benzylating agent was observed as benzyl chloride > benzyl alcohol > dibenzylether. This study indicated that biomass derived activated carbon is suitable support to disperse Keggin type heteropoly acid for the benzylation reaction.

The mixed system of ionic liquid (IL) tetraethyl ammonium tetrafluoroborate [TEA(BF 4 )] and numerous ethylene oxide based non-ionic surfactants in aqueous media were studied using surface tension, viscosity and dynamic light scattering (DLS) measurements. Various surface properties like critical micelle concentration (cmc), maximum surface excess concentration (Γ max ), minimum surface area per surfactant molecule ( A min ), surface tension at the cmc ( γ cmc ), adsorption efficiency ( pC 20 ), and effectiveness of surface tension reduction ( π cmc ) as well as thermodynamic parameters of micellization have been determined. DLS and viscosity measurements revealed that the micellar growth was attributed to the bridged solvophilicity of the POE chain in surfactants at elevated temperatures. In most of the cases, the progression ensues from exothermic to endothermic with increase in temperature of the mixed system. Thermodynamic parameter indicates that the micelle formation process is enthalpy driven at low temperature and entropy driven at higher temperature.

Levulinic acid (LA) has been recognized as a versatile building block for the synthesis of various organic chemicals as it contains ketone and carboxylic functional groups. Levulinate esters are important chemical feedstocks having potential applications either in flavouring and fragrance industries or biodiesel as blending component. The present work focuses on the synthesis of n-butyl levulinate by esterification of LA with n-butanol using various small and large pore zeolites. The preferential order to yield n-butyl levulinate was found to be: H-BEA > H-Y > H-ZSM-5 > H-MOR. Further, a study for optimizing the reaction conditions such as acid to n-butanol molar ratio, reaction time and catalyst concentration has been described. Under optimized reaction conditions, zeolite H-BEA has been found as most efficient catalyst with 82.2 % LA conversion and 100 % selectivity of n-butyl levulinate. Scheme: Zeolite catalyzed esterification of levulinic acid

In the present study conversion of waste cooking oil to biodiesel has been carried out via simultaneous esterification and transesterification reaction over silica sulfuric acid as a solid acid catalyst. The process variables that influence the fatty acid methyl ester (FAME) conversion, such as reaction temperature, reaction time, catalyst concentration and methanol to oil molar ratio were investigated and optimized using Taguchi method. Highest FAME production obtained under the optimized condition was 98.66 %. Analysis of variance revealed that temperature was the most significant factor effecting the FAME production among four factors studied. From the kinetic study, the reaction was found to follow pseudo first-order kinetics and rate constant of the reaction under optimum condition was 0.00852 min−1.

Fuels from biomass (biofuels) are used to mitigate the greenhouse gases produced through the utilization of fossil fuels. Non-edible or waste biomass can be pyrolyzed to produce bio-oil. The oil, an unstable and low energy product, can be further upgraded through hydrodeoxygenation to produce gas and/or diesel range hydrocarbons and value added chemicals. The objective of this review is to explore upgrading techniques that are currently being researched and utilized. This review reveals several aspects that in turn will serve as an aid for bio oil valorization, such as, evaluating characterization techniques involved in understanding salient features of bio-oil, insight of bio-oil pretreatment methods for water removal to increase heating values and decrease risk of catalyst poisoning in subsequent hydroprocessing, studies regarding model compound upgrading, reaction mechanism and finally, provides brief review of common catalysts for hydrotreatment of bio-oil in order to yield value added chemicals and fuels.

This paper deals with esterification of free fatty acids (FFAs) in acid oil (a byproduct of oil refining) to obtain biodiesel. Sulfonic acid-functionalized silica (SiO2–Pr–SO3H) was used as promising solid-acid catalyst. The conditions affecting conversion to fatty acid methyl esters (FAME), for example reaction temperature, reaction time, catalyst concentration, and methanol-to-oil molar ratio, were investigated and optimized by use of the Taguchi method. The highest conversion obtained under the optimized conditions was 96.78 % after 8 h. Analysis of variance revealed that temperature was the most significant factor effecting conversion among the four conditions studied. The experimental results were found to fit a pseudo first-order kinetic law. SiO2–Pr–SO3H is a highly effective, reusable, and environmentally benign catalyst for biodiesel production from waste low-cost oil feedstock with a high FFA content.

Heterocyclic quinazolinone-based hot brand monoazo reactive dyes were obtained by diazotization of 3-(4-aminophenyl)-2-phenylquinazolin-4(3H)-one and coupling with a variety of cyanurated coupling components. All the heterocyclic hot brand monoazo reactive dyes were characterized by elemental analysis (C, H, N) and by use of spectroscopic techniques (FT-IR, UV–visible, 1H NMR). Their performance as reactive dyes was assessed on silk, wool, and cotton fabrics. The dyes were found to give a variety of color shades with very good depth and uniformity on the fibers. The fastness of all the dyes on the fibers was moderate to excellent. Colorimetric data (L*, a*, b*, C*, H*, and K/S) of the synthesized dyes were also studied in detail.

Some novel benzoquinoline based heterocyclic monoazo dyes have been derived by the diazotization of 1H-benzo[g]pyrazolo[3,4-b]quinoline-3-ylamine with various phenyl pyrazolone as coupling components. All the heterocyclic monoazo dyes have been characterized by elemental analyses and various spectral data (FT-IR, UV–Vis, 1H NMR and 13C NMR), and their 3D model structures were predicted through B3LYP/6-31G(d,p) method. The dyeing performance on polyester fibers inferred that all the dyes gave moderate to excellent fastness properties on fiber. In addition, colorimetric studies of synthesized dyes have also been discussed.

A series of diarylpyrymidin-2(1H)-one (DAPM) belongs to one of the important class of therapeutic and pharmacological active hetrocycles, were synthesized through the multicomponent reactions (MCRs) of aldehydes, ketone and urea, followed by the heterogeneous catalysis. The synthetic utility of this method is well demonstrated by avoiding expensive reagent TMSCl, using large pore zeolites (H-MOR, HY and H-BEA) as potential solid acid catalyst. Key role of textural properties such as surface acidity, hydrophobicity and porosity on catalytic activity of the zeolites on the synthesis of DAPMs has also been described.

Heterocyclic monoazo quinazolinone based azo dyes derived by the diazotization of 3-(4-aminophenyl)-2-phenylquinazolin-4(3H)-one with various phenyl pyrazolones based coupling components. All the heterocyclic azo dyes have been characterized by their percentage yield, UV-VIS spectroscopy, elemental analysis, IR spectroscopy, 1H NMR spectroscopy, and dyeing performance on silk, wool, nylon, and polyester fibers. All the dyes gave moderate to excellent fastness properties on each fiber. The main focus was to synthesize heterocyclic monoazo dyes that give good dyeing property along with pharmacological activity (anti bacterial and antifungal). Therefore, the synthesized compounds were examined for their antimicrobial activity at various concentrations using well-known Kirby-Bauer disk diffusion method.

Coupling of various phenyl pyrazolone derivatives with diazonium salt of 1H-benzo[g]pyrazolo[3,4-b]quinoline-3-ylamine gave a series of heterocyclic azo compounds. All the synthesized azo compounds have been characterized by their percentage yield, elemental, and spectral analyses. These new compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. Furthermore, the synthesized compounds were tested for in vitro antituberculosis activity against Mycobacterium tuberculosis. Streptomycin, Isoniazid, Rifampicin, and Ethambutol were used as standards in this investigation.

Heterocyclic monoazobenzoquinoline-based azo dyes have been derived by diazotization of 1H-benzo[g]pyrazolo[3,4-b]quinoline-3-ylamine with a variety of phenylpyrazolone-based coupling compounds. The synthesized dyes were characterized by determination of their percentage yield, by elemental analysis, and by UV–visible, IR, and 1H NMR spectroscopy. Dyeing performance on silk, wool, nylon, and polyester fibers was assessed. The fastness properties of the dyes on each fiber were moderate to excellent. The antimicrobial activity of the dyes at different concentrations were also examined, by use of the Kirby–Bauer disk diffusion method.

A series of dihydropyrimidin-2(1H)-one (DHPM) belongs to one of the important class of therapeutic and pharmacological active compound, were synthesized through the multicomponent reactions (MCRs) of aldehydes, ethyl acetoacetate and urea, followed by the heterogeneous catalyzed Biginelli reaction. In the present endeavour, medium (ZSM-5) and large pore zeolites (Y, BEA and MOR) as well as dealuminated zeolites BEA, were studied as catalysts. An excellent activity for DHPMs synthesis is achieved by optimizing accessibility of the reactants to the active sites and the surface polarity of zeolite catalysts. Moreover, the mechanism of Biginelli reaction was studied by means of GAUSSVIEW energy calculations of adsorbed acylimine intermediate on zeolite by using the density functional method (DFT). Zeolite assisted heterogeneous Biginelli reaction

Conversion of high free fatty acids (FFA) containing acid oil (AO) to fatty acid methyl esters (FAME) using silica sulfuric acid (SSA) as a solid acid catalyst was investigated. Process parameters such as reaction temperature, reaction time, catalyst loading, and methanol to oil molar ratio were optimized using the Taguchi orthogonal array method. Maximum FFA conversion (97.16 %) was achieved under the optimal set of parameter values viz. 70°C, 4 mass % catalyst loading, and 1: 15 oil to methanol molar ratio after 90 min. SSA was reused three times successfully without a significant loss in activity. Biodiesel produced from AO met the international biodiesel standards. Determination of kinetic parameters proved that the experimental results fit the pseudo first order kinetic law.

Compared to conventional methods employing solvents, the introduced synthesis under solvent-free conditions has the advantages of shorter reaction times, simple work-up, environmental friendliness, excellent yields, cost effective recovery and reusability of catalyst for a number of times without significant loss of activity.