Anhydrous Zinc Chloride Research Articles

Synthesis and in silico ADMET prediction of the properties of novel sulfonyl indole derivatives

The article presents a method for synthesizing sulfonyl-derived indoles by rearranging the corresponding N-arylhydrazones through boiling in acetic acid saturated with dry hydrogen chloride and the addition of anhydrous zinc chloride. The ADMET resource was used to predict the pharmacokinetic indicators of absorption, distribution, metabolism, and excretion of the synthesized compounds. The study compared the predicted activity of synthesized compounds to that of active drugs containing an indole fragment, specifically indole-3-carbinol and diindolylmethane. The results indicate that the introduction of a sulfonyl group has a positive effect on the pharmacokinetic indicators of the synthesized compounds, which are comparable to those of the active drugs. Sulphonyl-derived indoles have the potential for oral administration due to their good indicators of intestinal absorption (0.009–0.097). Additionally, there is no negative effect on the central nervous system as indicated by their indicators of penetration through the blood-brain barrier (0.003–0.008). Furthermore, the compounds did not exhibit inhibition of cytochrome P450 (CYP) enzymes. Rats are potential candidates for further in vivo studies due to their low rates of mutagenicity, carcinogenicity, and acute toxicity.

Effect of milling atmosphere on stability and surface properties of ZnO/vermiculite hybrid nanocomposite powders

The zinc acetate dihydrate and anhydrous zinc chloride were used as precursors for the sonochemical preparation of the zinc oxide/vermiculite and organically modified zinc oxide/vermiculite_chlorhexidine nanocomposite materials. The nanocomposites were mechanically processed via a high-energy ball milling for 30 min at 300 rpm using two types of atmospheres an air or a nitrogen. Changes in temperature and pressure inside the grinding vessels were measured during mechanical processing in an air atmosphere. The ZnO(Cl)/V_30/300 sample reached the highest pressure (1161 mbar) and temperature (30.3 °C) in the milling vessels and for the ZnO(ac)/V_CH_30/300 sample the highest temperature difference was measured at the beginning and at the end of the milling (7 °C). The phase transformation, chemical composition and particle size of the hybrid nanocomposite materials were investigated using X-ray diffraction method, Fourier-transform infrared spectroscopy, X-ray fluorescence spectroscopy, carbon phase analysis and particle size distribution analysis. Changes in morphology and particle arrangement were characterised using scanning electron microscopy. The effect of mechanical processing in a protective atmosphere on surface properties such as specific surface area, surface conductivity and ζ-potential were demonstrated in relation to the type of precursor used for the preparation of ZnO nanoparticles in the structure of hybrid nanocomposite materials.

Docking, Synthesis and Evaluation of 4-hydroxy-1-phenyl-2(1H)-quinolone Derivatives as Anticancer Agents.

The estimated number of cancer cases in India for the year 2022 was found to be 14,61,427. The development of chemotherapeutic agents has reduced the mortality rate, however, they have high toxicity which is a disadvantage. Many researchers have found out that quinolin-2- one possesses anticancer activity, with this background we thought of synthesizing the quinolin-2-one derivatives. This study aimed to carry out docking, synthesis, characterization, and evaluation of 2-(2- (4-Hydroxy-2-oxoquinolin-1(2H)-yl)phenyl/ substituted phenyl)-3-(phenylamino) thiazolidon-4-one derivatives (IVa-g) as an anticancer agent. Diphenylamine and malonic acid treated with phosphoryl chloride gave compound I, which on formylation afforded compound II, which on reaction with various substituted aromatic phenylhydrazine derivatives gave compounds IIIa-g, which on further reaction with thioglycolic acid and anhydrous zinc chloride yielded the compounds IVa-g. Among all the synthesized novel derivatives, compounds IV a-d showed 50% lysis in the IC50 range of 25-50μg for the A549 cell line, and compounds IVa, and IVb showed 50% lysis in the IC50 range of 25-50μg for the MDA-MB cell line. The compound, 3-((4-fluorophenyl)amino)-2-(2-(4- hydroxy-2-oxoquinolin-1(2H)-yl)phenyl)thiazolidin-4-one (IVg) was found to be the most active against both the cell line, A549 and MDA-MB with IC50 value of 0.0298μmol and 0.0338μmol respectively. The docking results revealed that the synthesized compounds exhibited well-conserved hydrogen bonding with one or more amino acid residues in the active pocket of EGFR tyrosine kinase domain with 4-anilinoquinazoline inhibitor erlotinib (PDB ID:1M17). Compound IVg showed the highest MolDock score of -137.813 compared to the standard drug Imatinib having a MolDock score of -119.354. Compound IVg showed the highest MolDock score and was also found to be most potent against both the cell line, A549, and MDA-MB.

Synthesis, characterization and evaluation of antimicrobial potential of zinc(II) complexes of nitro-substituted hydroxamic acid chelators

The nitro-substituted hydroxamic acid chelators potassium 4-nitrobenzohydroxamate (4-(NO2)C6H4CONHOK) (KHL1) and 3,5-dinitrosalicylhydroxamate (3,5-(NO2)2(OH)C6H2CONHOK) (KHL2) on reaction with anhydrous zinc(II) chloride (ZnCl2) in 1:2 metal:ligand ratio in MeOH + THF afforded new zinc(II) complexes, [Zn(4-(NO2)C6H4CONHO)2] (1) and [Zn(3,5-(NO2)2(OH)C6H2CONHO)2] (2). The structural characterization of 1 and 2 has been accomplished by physicochemical studies; elemental analyses, molar conductivity, cyclic voltammetry and spectroscopic techniques in the solid state (IR) and in solution (1H NMR and UV-visible). The stoichiometric composition of 1 and 2 has been authenticated by mole ratio method and the stability constants were determined. IR spectral studies suggested the bidentate nature of ligands involving bonding through carbonyl and hydroxamic oxygen atoms (O,O’-coordination). The mass spectral data of 1 and 2 have indicated these to be mononuclear. In order to infer the biological relevance of newly synthesized complexes, the in vitro antimicrobial activity assay against pathogenic gram-ve bacteria, viz. Salmonella typhi and Escherichia coli; gram + ve bacteria Bacillus cereus and Staphylococcus aureus and fungi Rhizoctoniasolani and Fusarium sambucinum by MIC method has shown appreciable antimicrobial potential. The results have been compared with standard Tetracycline and Nystatin drugs.

Synthesis of Novel Benzoxazole Derivatives: Exploration of Their Possible Pharmacological Profiles with Computational Studies

Based on the interaction with PDB protein 1PXX of the cox-2 enzyme, a novel series of substituted thiazolidinones (TZD 5a-s) and azetidinones (AZT 6a-s) was designed and synthesized. Molecules were synthesized from 2-mercapto benzoxazole (1) using both conventional and microwave irradiation methods, and their in-vitro antioxidant activity was evaluated using the DPPH free radical scavenging activity, as well as their in-vivo anti-inflammatory activity using the carrageenin-induced rat paw edema method. The reaction time, yield, and purity of microwave and conventionally produced molecules are compared in this work. The molecule ethyl 2-(benzoxazol-2-ylthio)acetate (2) is obtained by reacting 2-mercapto benzoxazole (1) with ethyl 2-chloroacetate in the presence of potassium carbonate and dry acetone. The molecule 2-(benzoxazol-2-ylthio)acetohydrazide (3) was synthesized by reacting ethyl 2-(benzoxazol-2-ylthio)acetate (2) with hydrazine hydrate in the presence of absolute alcohol. Compound 2-(benzoxazol-2-ylthio)acetohydrazide (3) on reacting with different aromatic and heterocyclic aldehyde derivative forms 2-(benzoxazol-2-ylthio)-N'-substituted acetohydrazide Schiff bases (4a-s). 2-(benzoxazol-2-ylthio)-N-(4-oxo-2-substituted thiazolidin-3-yl)acetamide (5a-s) i.e. thiazolidinones benzoxazole derivatives obtained on reacting Schiff bases (4a-s) with thioglycolic acid in a dioxane medium and anhydrous zinc chloride. The Schiff bases (4a-s) were converted into 2-(Benzo[d]oxazol-2-ylthio)-N-(3-chloro-2-oxo-4-substituted azetidin-1-yl)acetamide (6a-s) after treatment with chloroacetyl chloride in the presence of triethanol amine and dioxane. This study focuses on screening of novel synthesized benzoxazole derivatives for in vitro antioxidant, in vivo anti-inflammatory activity, and the evaluation of ulcerogenic activity. The in vivo activity is correlated with the in silico activity, the 3 D QSAR studies were performed for all the compounds by using computer program i.e. SYBYL-X 2.1.1 software. The best CoMFA and CoMSIA models were obtained for the training set compounds with 0.753 and 0.646 leave-one-out coefficients (q2), 0.714 and 0.619 cross validated correlation coefficients (r2cv), and 0.975 and 0.983 conventional coefficients (r2), respectively. Both models were validated with a test set of eight compounds, giving the CoMFA and CoMSIA models a satisfactory prediction (r2pred) of 0.788 and 0.663, respectively. The findings of the study would provide valuable information for the design of new compounds and would also help in predicting the activity of designed compounds. To identify the lead molecule docking studies are performed on COX-2 enzyme of protein 1PXX, the molecules 5c, 5q, 5j, 6q, and 6 g derivatives obtained good - c-docker interaction energy respectively, and in vivo acute ulcerogenic activity.

SYNTHESIS, COMPUTATIONAL AND IN VITRO ANTI-DIABETIC STUDIES OF NOVEL THIAZOLIDIN-4-ONES DERIVATIVES

A new series of thiazolidin-4-ones (T1-10) were synthesized by the reaction of Schiff’s bases(Ta-j) and thioglycolic acid in dioxane medium in the presence of anhydrous zinc chloride as a catalyst. All the newly synthesized compounds were characterized by IR, 1H-NMR and mass spectral data and studied for in vitro antidiabetic activity. Most of the synthesized derivatives showed promising antidiabetic activity. This work indicates that the presence of the -OH group attached to the ring may be responsible for the activity. The new compounds were subjected to in silico analysis.

DESIGN, SYNTHESIS AND EVALUATION OF NOVEL AZETIDINONYL/ FORMAZONYL/ THIAZOLIDINONYLPHENOTHIAZINES AS POTENTIAL ANTI-INFLAMMATORY AGENTS

The present study describes the synthesis, full characterization and biological evaluation of novel azetidinonyl/formazonyl/thiazolidinonylphenothiazines. The synthesis of these compounds as potential anti-inflammatory agents was carried out using a more efficient and versatile synthetic route. Various 4-substituted phenyl-1-(10’-acetylaminophenothiazinyl)-azetidin-2-ones (9-13), 1-(10’-acetyliminophenothiazinyl)-3-substituted phenyl formazans (14-18) and 3-(10’- acetylamino-phenothiazinyl) -2-substituted phenyl-4-thiazolidinones (19-23) were synthesized by reacting 10-(various substituted phenylmethyleneimino) aminoacetylphenothiazines (4-8) with triethylamine / acetyl chloride, benzene diazonium chloride and thioglycolic acid / anhydrous zinc chloride, respectively. The structures of these compounds have been interpreted by elemental (C, H, N) and spectral (I.R., 1 H-NMR and mass) analysis. All the compounds were evaluated for their anti-inflammatory activity using rat paw oedema inhibition test and were compared with standard drugs. These compounds were also screened for acute toxicity studies. Compound 22 was the most potent compound of the series, exhibiting 82.44% oedema inhibition, interestingly more potent than the standard drug - phenylbutazone. All compounds showed ALD50 > 1000 mg kg -1 p.o. except compound 22, which exhibited ALD50 > 2000 mg kg -1 p.o.

Condition Optimization for Synthesis of 5-methyl-2(pyrimidin-2-yl) Benzoic Acid

Orexin has been emerged as a hot and frontier research theme in the close relationship with sleep-wake regulation. In this paper, we report a synthetic method for the preparation of 5-methyl-2- (pyrimidin-2-yl)benzoic acid, which is an important molecular fragment of orexin Filorexant (MK- 6096). Compared to the previously reported methods, the current route has the advantages of a short synthetic pathway, simple post-treatment, and high yield that provide an effective new methodology for the synthesis of the target compound. Using 2-bromo-5-methyl benzoic acid and 2- chloropyrimidine as raw materials, PdCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub> is used as a metal catalyst to mediate one-pot generation of 5-methyl-2-(pyrimidin-2-yl)benzoic acid using the Negishi cross-coupling method. The optimum condition involves 2-bromo-5-methylbenzoic acid (10.00 g) and anhydrous zinc chloride powder (6.32 g) together with the catalyst: 2-bromo-5-methylbenzoic acid molar ratio of 0.02 and 2- chloropyrimidine: 2-bromo-5-methylbenzoic acid molar ratio of 1.1:1 at a reaction temperature of 55°C for 14 h. Under these optimum reaction conditions, the maximum yield of 78.4% is attained for 5- methyl-2-(pyrimidin-2-yl) benzoic acid.

Reinforced mechanical properties and heat resistance of recycled acrylonitrile‐butadiene‐styrene/anhydrous zinc chloride coordination composites

AbstractIn this work, the recycled acrylonitrile‐butadiene‐styrene (rABS)/anhydrous zinc chloride (ZnCl2) composites were prepared and the reinforcing effects of the rABS/ZnCl2 composites were investigated using various characterization techniques. During heat pressing at 190°C, a strong coordination interaction occurred between Zn2+ of ZnCl2 particles and CN groups of rABS matrix, which resulting in an enhancement of mechanical and thermal properties in comparison with the neat rABS. Fourier transform infrared spectroscopy, dissolution experiments, ultraviolet–visible spectroscopy, and X‐ray photoelectron spectroscopy were applied to prove the coordination reaction. Scanning electron microscopy showed ZnCl2 particles were homogeneously dispersed in the rABS matrix. Tensile test analysis showed that the flexural strength and tensile strength of rABS/ZnCl2 composites increased by around 12.07% and 18.17%, respectively, when adding 7 phr of ZnCl2 into the rABS resin. Furthermore, heat deflection temperature analysis, thermogravimetric analysis as well as dynamic mechanical analysis proved that the coordination reaction dramatically improved the heat resistance of rABS matrix. Besides, the recycling ability of the composites had also been proved.

Synthesis and Bioactivity Screening of New 1, 3-Thiazolidin-4-One Compounds Bearing (Thiadiazols / Triazoles) Moieties

This article deals with synthesis, Identification and biological activity screening of variety 1,3-thiazolidin-4-ones entitled 3,3’-(benzene-1,3-diyldi-1,3,4-thiadiazole-5,2-diyl)bis[(5-methyl-2-(5-substitutedpyridine-2-yl)-1,3-thiazolidin-4-one)] 6a-d and 3,3’-[benzene-1,3-diylbis(5-mercapto-4H-1,2,4-triazole-3,4-diyl)]bis[5-methyl-2-(5-substitutedpyridine-2-yl)-1,3-thiazolidin-4-one], 7a-d. On cyclocondensation reaction of newly Schiff bases and thiolactic acid, some new derivatives of 1,3-thiazolidin-4-ones have been obtained in presence of anhydrous zinc chloride. The elemental analysis, proton NMR spectra of were outlined for structures confirmation. An agreement for the proposed structures of synthesized compounds were approved based on the elemental analysis, IR and 1H NMR spectra. Antimicrobial activity of the newly thiazolidinones have been evaluated with powerful results.

Boosting 3H-Benzo[f]chromen-3-one Chalcone with Anti-inflammatory Drugs: Synthesis, Characterization, and Evaluation of Cytotoxicity and Antimicrobial Activity

A series of novel 3H-benzo[f]chromen-3-one derivatives bearing non-steroidal anti-inflammatory drug moieties were synthesized with good yields. Benzo[f]coumarin chalcone was prepared via Claisen–Schmidt condensation between 2-acetyl-3H-benzo[f]chromen-3-one and 4-hydroxybenzaldehyde in basic medium and was then esterified with carboxylic acids (drugs) in the presence of phosphoryl chloride and anhydrous zinc(II) chloride. The newly synthesized compounds were characterized by FT-IR and 1H and 13C NMR spectra and elemental analyses and were screened in vitro for their anticancer and antimicrobial activity. Some of the tested compounds showed a good activity in comparison to standard drugs.

Lewis Acid Promoted Cyclization of Acyclic Urea Derivatives to Quinazolinediones

AbstractQuinazolinediones have gained special interest among researchers as they are known to have many pharmacological and medicinal uses. Here, we report an efficient way to synthesize quinazolinediones through the cyclization of acyclic ureido‐benzoate esters, catalyzed by anhydrous zinc chloride under mild conditions. A series of quinazolinediones was synthesized in good yield by reacting the corresponding ureido‐benzoate esters using this protocol. The quinazolinedione products were characterized using NMR, IR, HRMS spectroscopy and single crystal x‐ray diffraction analysis. We also present here a most plausible mechanism for the cyclization reaction.

Synthesis and anti-nociceptive potential of isoxazole carboxamide derivatives

BackgroundIsoxazole is an important pharmacophore in medicinal chemistry with a wide range of pharmacological activities. The present study deals with the synthesis and evaluation of antinociceptive potential of nine novel 3-substituted-isoxazole-4-carboxamide derivatives.SynthesisIn the first step, respective oxime was prepared and further treated with ethylacetoacetate and anhydrous zinc chloride followed by hydrolysis of ester to furnish 3-substituted isoxazole-4-carboxylic acid. The respective carboxylic acids were converted to acid chlorides and condensed with aromatic amines to get the target carboxamide derivatives (A1–A5 and B1–B5). These compounds were characterized by FTIR, 1HNMR, 13CNMR and elemental analysis data and screened for their analgesic activity using acetic acid-induced writhing assay and hot plat test in mice and compared with the standard centrally acting analgesic, tramadol.ResultsAll the synthesized carboxamide derivatives showed low to moderate analgesic activity. Among the synthesized derivatives B2 having methoxy (OCH3) showed high analgesic activity as compared to tramadol both in acetic acid-induced writhing assay and hot plate assay at dose of 6 mg/kg. To examine the involvement of opioidergic mechanism in the mediation of analgesic effects of isoxazole derivatives animals were further treated with non-selective opioid analgesic, naloxone (0.5 mg/kg). The results showed that compounds A3 and B2 follow a non-opioid receptor pathway in the mediation of analgesic effects. Synthesized compounds A3 and B2 were docked against non-opioid receptors COX-1 (3N8X), COX-2 (1PXX) and human capsaicin receptor (HCR, 3J9J) to analyze their binding interactions. They showed binding energies in the range of − 7.5 to − 9.7 kcal/mol.ConclusionsThe results indicated that isoxazole carboxamide derivatives possess moderate analgesic potential especially compounds A3 and B2 can be considered as lead molecules and explored further for pain management with fewer side effects.

Fabrication and characterization of SnO2 nanorods for room temperature gas sensors

Highly sensitive large-scale tin oxide (SnO2) nanostructures were grown on a glass substrate by thermal evaporation of a mixture of anhydrous tin (II) chloride (SnCl2) and zinc chloride (ZnCl2) powders at 550°C in air. We demonstrate a single cell vapor deposition system to precisely control nanostructural morphology of SnO2 by changing the weight ratio of SnCl2 and ZnCl2 and growth temperature. The morphology and structural property of as-grown nanostructures were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The SEM images revealed that the SnO2 nanostructures with different densities, sizes, and shapes can be achieved by adjusting the weight ratio of SnCl2 and ZnCl2. A thin film gas sensor based on SnO2 nanostructures with diameter ∼20 nm and length ∼100 nm showed ∼85% sensitivity and 53 seconds of response time, whereas the nanorods with diameter ∼100 nm and length ∼ 1μm showed ∼50% sensitivity with 198 seconds response time. The nanostructured material with small size and shape showed better sensitivity on sensing at room temperature compared to previously reported SnO2 based sensors.

Molecular docking, molecular modeling, vibrational and biological studies of some new heterocyclic α-aminophosphonates

A new diphenyl (aryl) (Ǹ-quinazolin-4-yl-hydrazino) methylphosphonates 3a–3d was synthesized via anhydrous zinc chloride catalyzed Kabachnic-Fields reaction. The structure of the synthesized compounds was confirmed by elemental analysis, FT-IR, 1H NMR, 13C NMR, 31P NMR and MS spectral data. The synthesized compounds showed significant antimicrobial and also remarkable cytotoxicity anticancer activities against breast carcinoma cell line (MCF7). The quantum chemical calculations were performed using density functional theory (DFT) to study the effect of the changes of molecular and electronic structures on the biological activity of the investigated compounds. Also, NBO and theoretical FT-IR were calculated. The experimental results were validated by molecular docking simulation of compound 3b in the active pocket of the enzyme. The important binding interactions with the key residues in the active site were revealed. A good correlation was found between the quantum chemical parameters and experimental data.

Design, synthesis, molecular modeling, and biological evaluation of novel α-aminophosphonates based quinazolinone moiety as potential anticancer agents: DFT, NBO and vibrational studies

Diphenyl (aryl) (4-oxo-2-phenyl-4H-quinazolin-3-yl)-acetic acid hydrazino methyl phosphonate (IIIa-k) was achieved upon the reaction of 3, 4-dihydro-(4-oxo-2-phenyl-4H-quinazolin-3-yl)-acetic acid hydrazide I with various aromatic aldehydes (IIa-k), triphenylphosphite in the presence of anhydrous zinc chloride as a Lewis acid catalyst. The structure of the synthesized compounds was elucidated by FT-IR, 1H NMR,13C NMR, 31P NMR, elemental analysis and MS spectral data. The newly synthesized compounds were screened in vitro for their anticancer activities against four representative cell lines of HePG-2, MCF-7, HCT-116, and PC-3, and antioxidant activities. The results showed clearly that most of the synthesized α-aminophosphonates displayed an excellent to a moderate anti-proliferative activity against the four tested cell lines. Compounds IIIb and IIIk are the most potent antioxidant and anticancer agents. DFT calculations with B3LYP/6-31 + G (d) level were used to analyze the electronic and geometric characteristics deduced from the stable structure of the compounds. Theoretical FT-IR of all investigated compounds was studied to show a correlation between the theoretical wave numbers and the experimental ones. The principal quantum chemical descriptors showed a good correlation with the anticancer activity.

Composition of Concentrates Isolated by Complexation with Aluminum and Zinc Halides from Petroleum Fuel Fractions during Their Desulfurization

An experimental study on obtaining concentrates of organic compounds from fuel fractions of petroleum by complexation with metal halides: aluminum chloride, aluminum bromide, anhydrous zinc chloride, and its crystal hydrate has been performed. Optimal conditions have been selected for the complexation reaction of aluminum and zinc halides with electron-donor compounds of diesel and jet fuels. The degree of removal of organic sulfur compounds from the diesel or jet fuel by complexation with aluminum chloride reaches 79.6 or 10.0 rel. %, respectively. It has been found that the concentrates obtained contain a large amount of normal and weakly branched alkanes, which form clathrates with polar components of the donor–acceptor complex (DAC). A mechanism is proposed for the intermolecular interaction of alkanes with the DAC components by hydrogen bonding with halogen, oxygen, and sulfur atoms.

Synthesis of functionally substituted benzaldehydes

A new method of synthesis of functionally substituted benzaldehydes by catalytic debromometoxylation of dibromomethylarenes with benzaldehyde dimethyl acetal has been suggested. Anhydrous zinc chloride has been used as a catalyst. Being soft Lewis acid, it formed no strong complex with aldehyde group and other functional groups. The initial acetal has been readily recovered by the treatment of benzaldehyde isolated from the reaction mixture with trimethyl orthoformate.

Preparation of Activated Carbon from Heavy Crude Oil wastes for Removal of Nitrobenzene from Aqueous Solution

In this research, activated carbon (A.C) and non-activated carbon (N.A.C) have been produced from heavy crude oil wastes by distillation operations, carbonization and activation. Anhydrous zinc chloride (ZnCl2) (10% W/V) have been used for activation process with temperature of (500) ºC. Adsorption processes of Nitrobenzene on the surface of (A.C) and (N.A.C) have been studied at (pH = 7) with various periods for contact (10-120) minutes and with temperatures of (283, 293, 303, 313) K, using solutions of (50, 100, 150, 200) mg L versus grain size of carbon (Mesh 70). The results showed that the percentage of adsorption increases with increasing of temperature and contact time. The highest percentage of adsorption of Nitrobenzene reached to (98.40) %, using (A.C) and solutions of (100 mg L) concentration at contact time of (120 minutes) and temperature of (313 K), whereas a higher percentage of adsorption of Nitrobenzene reached to (97.05) %, using (N.A.C) at the same previous conditions.Equations of Frendlich, Langmuir and Temkin have been applied on the adsorption processes. The results showed that all of the equations fit with adsorption processes according to correlation factor values (R2). The thermodynamic functions have been calculated. Values of (ΔGº) showed that the adsorption processes were spontaneous. Values of (ΔHº) showed that the adsorption processes were physisorption and endothermic.

Synthesis of new 1-(3,4-dimethylphenyl)-1,5-dihydropyrazolo[3,4-d]pyrimidin-4-one derivatives

New substituted pyrazolo[3,4-d]pyrimidin-4-ones have been synthesized as a result of a series of transformations including hydrolysis of ethyl 5-amino-1H-pyrazole-4-carboxylates, cyclization of the carboxylic acids thus obtained to pyrazolo[3,4-d][1,3]oxazin-4(1H)-ones, and treatment of the latter with substituted anilines. The final pyrazolo[3,4-d]pyrimidin-4-one derivatives can also be synthesized from 5-(arylamido)-1H-pyrazole-4-carboxylic acids in the presence of a catalytic amount of anhydrous zinc(II) chloride.