Condensation Products Research Articles

Synthesis of high density and low freezing point jet fuels range cycloalkanes with cyclopentanone and lignin-derived vanillins

In this work, a “cyclopentanone-vanillin” strategy was proposed for the preparation of jet fuel range cycloalkanes from lignocellulose-derived ketones and lignin-derived aldehydes via aldol condensation and hydrodeoxygenation (HDO). Ethanolamine lactate ionic liquid (LAIL) exhibited excellent catalytic activity in the aldol condensation of cyclopentanone and vanillin. Desired mono-condensation and bi-condensation products were obtained with yield of 95.2% at 100 °C. It is found that the synergy effects between amino group of ethanolamine and hydroxyl group of lactic acid play a key role in the aldol condensation. The condensation products were converted into cycloalkanes by HDO over 5%Pd/Nb2O5 catalyst. The density of the obtained HDO products is 0.89 g/cm3 and the freezing point is lower than −60 °C. These results suggest that the resulted cycloalkanes can be used as additives to improve the density and low-temperature fluidity of the jet fuels.

Pyrrole Based Schiff Base as a Highly Sensitive Fluorescent Sensor for Fe3+ and Sn2+ Ions

Condensation product of o-aminophenol and pyrrole-2-carboxylaldehyde behaves as a fluorescent sensor for Fe3+ and Sn2+ ions in aqueous medium over the other metal ions like Na+, K+, Mg2+, Zn2+, Cd2+, Hg2+, Mn2+ and Cr3+. In aqueous solution, Fe3+ and Sn2+ ions coordinate to the receptor through a NON binding site which induces a strong fluorescence enhancement. Receptor can be applied as fluorescence enhanced probes for transition metal ions due to the inhibition of photo induced electron transfer (PET) mechanism.

Средне-щелочные алкилфенолятные присадки

The article presents the results of research on the sintesis of medium alkaline alkylphenolate additives. Additives are calcium salts of the condensation products of alkylphenols with formaldehyde and ammonia or various amines (monoethanolamine, benzylamine and allylamine) have been synthesized and studied. The physicochemical and functional properties of the synthesized products were studied by standard methods.It has been shown that all aminomethyl derivatives of alkylphenols have multifunctional properties and are superior to their analogs ИХП-101, ИХП-109 and ВНИИНП-370 in terms of their functional properties. In addition, the additives obtained on the basis of nonylphenol in terms of anticorrosion and antioxidant properties are somewhat superior to those obtained on the basis of alkylphenol (C8–C12) due to their homogeneous composition. Thus, all synthesized compounds are multifunctional, and additives containing a secondary nitrogen atom (calcium salt of dialkyldioxybenzylamine) and a benzyl radical at the nitrogen atom (calcium salt of N-benzyldialkyldioxybenzylamine) have the highest antioxidant efficiency.

Vapor-phase oxidation of propylene glycol-methanol mixture to methyl lactate on CeO2/Al2O3 catalyst

The vapor-phase oxidation of mixtures of propylene glycol with methanol and ethanol to methyl and ethyl lactate, respectively, on supported CeO2/Al2O3 catalyst at 210-2500С was investigated. Air oxygen and a flow reactor with a fixed catalyst bed were used. A 20% solution of propylene glycol in alcohol was supplied to the reactor inlet. Oxidation of propylene glycol in the presence of methanol occurs according to the overall reaction CH3CHOHCH2OH +O2 + СН3OH = CH3CHOHCOOСН3 +2H2O. First, hydroxyacetone is formed, which is further oxidized to pyruvic aldehyde, which adds alcohol to form a hemiacetal. Next, this hemiacetal is rearranged according to Cannizzaro into methyl lactate. At 2200C and catalyst load < 2 mmol PG/gcat/h, the selectivity for methyl lactate reached 70 wt.% at 100% propylene glycol conversion. In the presence of ethanol, the formation of a significant amount of acetaldehyde and its aldol condensation products, as well as the formation of diethoxyethane, was observed. Therefore, the selectivity for ethyl lactate at 100% propylene glycol conversion did not exceed 45%.

Новые экономические подходы к селективному управлению производственным развитием нефтегазового региона

Introduction: the oil and gas region economy is highly dependent on tax revenues from oil and gas companies and their service companies, whose profits, in turn, are significantly affected by the volatility of oil and gas prices in the world commodity markets. This determines the relevance of developing new economic approaches to managing the production development of the oil and gas region, taking into account the principle of selectivity in terms of the ratio between the share of oil and gas in regional mining activities and the share of the main types of products of the oil and gas processing industry in the manufacturing industries of a particular region. Objectives: to clarify the scientific category “oil and gas region”, to substantiate and introduce into scientific circulation of the category “inclusive production development of the region” and to pose the problem of the concept “Groningen effect” acceptability at the regional level on the example of the Volga Federal District. Methods: synthesis of institutional, systemic, structural-functional and innovative-technological methodological approaches to managing the production development of the oil and gas region. The criteria for the analysis are the percentage components of the oil and condensate production volumes, as well as natural and associated petroleum gases, in the volume of final production in “Mining” sector. These indicators are mathematically interconnected with indicators of the structure of shipped products in the production of coke and oil products, rubber, and plastic products in the “Manufacturing production” sector; as a result, the region’s oil and gas activity factor was formulated. Results: the author revealed a characteristic of oil and gas region production development, which was called “inclusiveness”. It is based on the investment strategy of diversified high-yield oil and gas revenues of the regional budget into horizontal industrial policy, considering the economic and geological features of oil and gas resource extraction and their quality composition in the Volga-Ural oil and gas-bearing province. The paper proposes the scientific problem “Groningen effect” in the Russian regional conditions and estimates the magnitude of manifestation of said effect by the main types of foreign trade products of the oil and gas region. Conclusions: the developed approach to economic identification of the oil and gas region can become an effective instrument of selective management of its production development under conditions of high volatility of hydrocarbon raw materials quotations, the sanctions on Russian exports and the transition to technological sovereignty.

Analyzing the Tendencies in Meeting the Country’s Needs for Motor Fuel

The aim of the article is to analyze the oil and petroleum products markets in Ukraine and tendencies in meeting the country’s needs for motor fuel. To achieve this aim, an analysis of the state of the oil and gas condensate market in Ukraine was carried out; the dynamics of oil and gas condensate consumption in Ukraine is studied; the main consumers and producers of motor fuel in Ukraine are identified; the dynamics of oil and gas condensate refining volumes is analyzed. The article also examines the dynamics of exports and imports of oil and gas condensate in Ukraine. The demand for crude oil and gas condensate in Ukraine is analyzed and it is determined that the dependence of domestic producers of light oil products on imported oil supplies significantly affects the oil market of Ukraine. The tendencies of oil and gas condensate production in Ukraine have been studied and their steady decline in recent years has been noted. The results of the study of the current state and trends in the development of the oil products market in Ukraine are presented. The dynamics of consumption and production, as well as the features of demand for motor fuel both in general and for its types in particular – motor gasoline, diesel fuel and liquefied natural gas (LNG) – are analyzed. The geographical structure of motor fuel imports by its individual types is analyzed. Their main importers in the Ukraine have been identified. The balance of the market for the main types of motor fuel has been studied.

СИНТЕЗ, СТРОЕНИЕ И МАГНИТНЫЕ СВОЙСТВА КОМПЛЕКСОВ Cu(II) НА ОСНОВЕ 4,6-ДИМЕТИЛПИРИМИДИЛГИДРАЗОНА ДИАЦЕТИЛМОНОКСИМА: ЭКСПЕРИМЕНТАЛЬНОЕ И ТЕОРЕТИЧЕСКОЕ ИССЛЕДОВАНИЕ

In order to study the effect of the dimethylpyrimine fragment nature on the structure and magnetic properties of coordination compounds, new binuclear Cu(II) metallochelates were synthesized. The coordination compounds are [Cu2(HL)2(CH3OH)2](ClO4)2 (1) and [Cu2(HL)2(NO3)2] (2), where HL – the monodeprotonated form of 2-hydrazino-4,6-dimethylpyrimidine and diacetylmonoxime condensation product. The structure and properties of complexes were established using elemental analysis, 1H NMR, IR-spectroscopy, magnetochemistry. It was shown that the coordination compounds are diamagnetic at room temperature due to the strong antiferromagnetic exchange interaction between paramagnetic Cu(II) ions: −2J > 1000 cm−1. The data obtained are in a good agreement with the results of quantum chemical calculations (theory level B3LYP/6 311G(d)).

Melamine-isatin tris Schiff base as an efficient corrosion inhibitor for mild steel in 0.5 molar hydrochloric acid solution: weight loss, electrochemical and surface studies.

In the current study, 3,3',3''-((1,3,5-triazine-2,4,6-triyl)tris(azaneylylidene))tris(indolin-2-one) (MISB), which is the condensation product of melamine (triazine) and isatin, was investigated as a mild steel corrosion inhibitor in 0.5 M HCl. The ability of the synthesized tris-Schiff base to suppress corrosion was evaluated utilizing weight loss measurements, electrochemical techniques and theoretical computation. The maximum inhibition efficiency of 92.07%, 91.51% and 91.60% was achieved using 34.20 × 10-3 mM of MISB in weight loss measurements, polarization, and EIS tests, respectively. It was revealed that an increase in temperature decreased the inhibition performance of MISB, whereas an increase in the concentration of MISB increased it. The analysis demonstrated that the synthesized tris-Schiff base inhibitor followed the Langmuir adsorption isotherm and was an effective mixed-type inhibitor, but it exhibited dominant cathodic behavior. According to the electrochemical impedance measurements, the Rct values increased with an increase in the inhibitor concentration. The weight loss and electrochemical assessments were also supported by quantum calculations and surface characterization analysis, and the SEM images showed a smooth surface morphology.

Gravity substructures of offshore oil and gas facilities

The article presents a review and analysis of using gravity substructures as supports for various offshore oil and gas facilities. It gives examples of oil and gas producing platforms with steel and reinforced concrete substructures. It also describes a modern offshore facility, a process line of the liquefied natural gas and stable gas condensate production, storage and shipment plant based on a reinforced concrete gravity foundation.

MOLECULAR BINDING OF 2-PHENYLETHYLAMINE BY β-CYCLODEXTRIN

The paper considers the results of an experimental study of the synthesis of 2-phenylethylamine, a biogenic amine, which is the initial link in natural neurotransmitters and is used in pharmacological practice as an antidepressant and a remedy for the treatment of neurological disorders. The target amine was synthesized by reduction of phenylacetonitrile with lithium borohydride and decarboxylation of the sodium salt of phenylalanine. The reduction reaction proceeds in aqueous ethanol at room temperature, which increases the yield of the product. At the same time, the resulting product quickly passes in air into an insoluble carbonate. Decarboxylation occurs when the sodium salt of phenylalanine is fused with an alkali, which leads to the partial formation of a condensation product, 3,6-dibenzylpiperazine-2,5-dione, at a high temperature. It is shown that both methods lead to the synthesis of the product with yields of about 45%. The inclusion complex of phenylethylamine with β-cyclodextrin, acting as an encapsulator - a container for molecular binding, was obtained by the suspension method. Binding occurs in an aqueous suspension, followed by washing the amine with acetone. The structure of the obtained compounds was proved by the method of nuclear magnetic resonance spectroscopy on 1H nuclei, as well as by thin-layer chromatography. Comparison of the integral intensities of the signals of the protons of the cyclodextrin framework and protons of the amino group of phenylethylamine showed that the process is accompanied by a transition to the bound form of 65% amine at a ratio of cyclodextrin : amine 3:2. It can be expected that such binding can be used in pharmacological practice to increase the stability of the amine, its targeted transport in the body and prevent premature processes of its destruction under the action of the monoamine oxygenase enzyme.

Binuclear azide-bridged hydrazone Cu(II) complex: Synthesis, characterization and evaluation of biological activity

The condensation product of 7-acetyl-6-azaindole and Girard?s T reagent ((E)-2-(2-(1-(1H-pyrrolo[2,3-c]pyridin-7-yl)ethylidene)hydrazineyl)- -N,N,N-trimethyl-2-oxoethan-1-aminium, HL ligand) was used as a ligand in the reaction with Cu(BF4)2?6H2O and NaN3. The reaction led to the formation of a binuclear Cu(II) complex containing two end-to-end (di-?-1,3-N3) azide bridges, as well as two NNO-donor hydrazone ligands, forming an axially elongated square pyramidal geometry around each Cu(II) center. This end-to-end (di- ?-1,3-N3) azide bridge binding mode has not yet been reported, in Cu(II) complexes containing the NNO-donor hydrazone ligands, which makes the structure of the complex even more interesting for further studies. The complex was characterized by elemental analysis, IR spectroscopy and X-ray crystallography, and it was found that it crystallizes in the triclinic space group P?1 with the asymmetric unit comprising one Cu(II) centre, zwitterionic ligand L, one azide (N3 -) ligand and BF4 - counter anion. Examination of antimicrobial activity of the complex shows higher antifungal and antibacterial activity towards tested Gram-positive bacteria in comparison to the hydrazone ligand, with the antifungal activity of the complex even being comparable to the activity of amphotericin B.

Evaluation of color and stability of ethyl-linked anthocyanin-flavanol pigments in model wine solutions using combined chemical analysis and 3D molecular simulations

Ethyl-linked anthocyanin-flavanol pigments are one of the most important condensation products formed during the red winemaking and ageing period. They have great contribution to the color characteristics and stability of aged red wines. In this study, the color characteristics and stability of ethyl-linked anthocyanin-flavanol pigments and their precursor anthocyanins were evaluated by combined spectrophotometry and 3D molecular simulations. In model wine solutions, the condensation reactions between three anthocyanins and (-)-epicatechin, mediated by acetaldehyde, were conducted to produce ethyl-linked anthocyanin-flavanol pigments. The color was assessed by the CIELab method, and the concentration changes were analyzed by HPLC-DAD. On the other hand, the stability of these pigmented compounds was also calculated by the three 3D molecular simulation methods, that is molecular mechanics, molecular dynamics, and quantum chemistry simulation. The results obtained from CIELab analysis indicated that the formation of ethyl-linked anthocyanin-flavanol pigments resulted in a decrease of L*, a*, b* and C* values, and conversely, a rising of h* value. The 3D molecular simulations revealed that the stability of anthocyanins was as follows: Mv-3-O-glu > Pn-3-O-glu > Cy-3-O-glu. The cis or trans ethyl-linked anthocyanin-flavanol pigments were much more stable than their precursor anthocyanins. Among the pigments, ethyl-linked malvidin-3-O-glucoside-flavanol was more stable than ethyl-linked cyanidin-3-O-glucoside-flavanol and ethyl-linked peonidin-3-O-glucoside-flavanol.

Synthesis of novel pyrimido[4,5-e]indolizine- and pyrimido[5,4-c]quinolizine-6-carboxylic acids

An effective method for the synthesis of previously undescribed 1,3,4,5,6a,7,8,9-octahydropyrimido[4,5-e]indolizine- and 1,3,4,5,7,8,9,10-octahydro-2H-pyrimido[5,4-c]quinolizine-6-carboxylic acids by hydrolysis and decarboxylation of new spiro-substituted derivatives was proposed. The corresponding spirocyclic derivatives were obtained by boiling of 6-dialkylamino-1,3-dimethyl-5-formyluracils with Meldrum's acid in acetonitrile. The reaction proceeds according to the tert-amino effect mechanism without the release of Knoevenagel condensation products

Machine-learning-accelerated Bose-Einstein condensation

Machine learning is emerging as a technology that can enhance physics experiment execution and data analysis. Here, we apply machine learning to accelerate the production of a Bose-Einstein condensate (BEC) of $^{87}\mathrm{Rb}$ atoms by Bayesian optimization of up to 55 control parameters. This approach enables us to prepare BECs of $2.8\ifmmode\times\else\texttimes\fi{}{10}^{3}$ optically trapped $^{87}\mathrm{Rb}$ atoms from a room-temperature gas in 575 ms. The algorithm achieves the fast BEC preparation by applying highly efficient Raman cooling to near quantum degeneracy, followed by a brief final evaporation. We anticipate that many other physics experiments with complex nonlinear system dynamics can be significantly enhanced by a similar machine-learning approach.

Anti-proliferative activities of 4H-pyran derivatives synthesized from benzoylacetone

ABSTRACT. Benzoylacetone (1) underwent a series of multi-component reactions with aromatic aldehydes and malononitrile or ethyl cyanoacetate to produce the pyran derivatives 4a-f. The latter compounds reacted with malononitrile or ethyl cyanoacetate to yield the condensation products 5a-m. On the other hand, the reaction of 4a-f with either the diazonium salts 6a-c yielded the arylhydrazone derivatives 7a-i. The multi-component reaction of (1) with aromatic adehydes and cyclohexan-1,3-dione produced the pyran derivatives 9a-c. Compound 1 underwent the Gewald’s reactions with elemental sulfur and malononitrile or ethyl cyanacetate yielding the thiophene derivatives 10a,b. Evaluations of the synthesized products were carried out against some selected cancer cell lines and the most active compounds were further evaluated against the seventeen cancer cell lines classified according to the disease. Morphological changes of A549 cell line by the effect of compound 7k was studied using microenvironment of the lung tissue where an excellent results was obtained.
 
 KEY WORDS: Benzoylacetone, Multi-component reactions, Pyran, Thiophene, Arylhydrazone, Cytotoxicity
 
 Bull. Chem. Soc. Ethiop. 2023, 37(2), 405-425. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i2.12

Integrating computational fluid dynamic, artificial intelligence techniques, and pore network modeling to predict relative permeability of gas condensate

The formation of gas condensate near the wellbore affects the gas liquid two-phase flow between the pores. It may occur in the path between two pores depending on the thermodynamic conditions of the single-phase gas flow, two-phase gas liquid annular flow or the closed path of condensate in the throat. To model the behavior of gas condensate in a network of pores, relative permeability and naturally pressure drop should be calculated. This study obtained the flow characteristics (pressure drop) between the pores at different physical and geometric conditions using computational fluid dynamics (CFD). CFD is time-consuming, so its results were transferred to an artificial neural network (ANN) model and the ANN model was trained. The CFD was replaced with the ANN model for calculating the pressure drop. In addition, instead of utilizing empirical correlations to compute the accurate value of condensate formed in throats' corners at every time step, the flash calculation using Esmaeilzadeh–Roshanfekr equation of state was performed, and closed throats were specified. This accurately estimates gas and condensate distribution in the pore network. Furthermore, the value of condensate that transferred to the adjacent throats was computed using Poiseuille's law. The results showed that the proposed ANN-based proxy model could promote the calculation speed in gas condensate simulation, considering the dynamic change of relative permeability curves as a function of gas condensate saturation. Also, it was found that the relative permeability obtained by the proposed model is in good agreement with the experimental data. By entering the fractures pattern in the network model and predicting the relative permeability of gas and condensate by the proposed method, the role of fractures in gas condensate production in such reservoirs could be predicted. Dynamic changes due to the relative permeability of gas and condensate as a function of saturation can be entered into the reservoir simulation to optimize inertia and positive coupling phenomena to maximized condensate production in gas condensate reservoir.

Pyrolysis of mixed plastic waste: Predicting the product yields

The predictability of pyrolysis yields and product composition of mixed plastics has been studied. To do so, pyrolysis of virgin polymers (HDPE, LDPE, PP, PS and PET) and eight individual sorting categories from a real waste DKR-350 stream (PE rigid/film, PP rigid/film, PET, PS, multilayer flexibles, and clogged materials) was performed in a batch reactor at 500 °C at laboratory scale. The obtained oil/wax, gas, and solid yields and the composition of oil/wax of those individual feedstocks were used as input of a superposition model to predict the corresponding pyrolysis yields and oil/wax composition of mixed feeds, which were later compared with the experimentally measured product yields from the pyrolysis of those mixed streams. This linear model predicts the oil/wax yield of the mixed streams to a reasonable extent, with a maximum yield deviation (overestimation) of 8 percentage points. However, the presence of significant amounts of PET (above 33 wt%) in the mixed plastic streams negatively impacts the production of the condensable product and promotes the formation of solid products beyond the expected predicted values. Quantification of the type of carbon (aliphatic, aromatic and carbonyl) present in all the oil/wax products was done using 13C NMR spectroscopy. A linear model could also predict the aliphatic carbon yield in the condensable product from plastic waste streams with high accuracy (maximum yield difference of 6 percentage points). However, the aromatic carbon yield could not be predicted, probably due to the observed behavior of PET, which interacts with other polymers to promote solid product formation.

Synthesis of New Isoquinoline Derivatives from the Condensation Products of Acid Anhydrides and 2-(3,4-Dimethoxyphenyl)ethanamine

Synthesis of New Isoquinoline Derivatives from the Condensation Products of Acid Anhydrides and 2-(3,4-Dimethoxyphenyl)ethanamine

Recovery of pure lead and preparation of nano-copper from waste glass diodes via a clean and efficient technology of step-by-step vacuum evaporation-condensation

Waste glass diodes, generated vastly with discarded printed circuit boards, are rich in metal resources while carriers of hazardous heavy metals. They require proper treatment to recover metals and avoid heavy metal contamination, but relevant research is insufficient currently. Thus, an environmentally-friendly and efficient technology of step-by-step vacuum evaporation-condensation was proposed in this study to recover lead and prepare nano-copper particles. A heat transfer model was established to guide the evaporation process with the purpose of effective treatment and energy-saving. According to the model, metal materials and the heating equipment could reach the endpoint of the set temperature T1 almost simultaneously when T1 ≥ 600 ℃. In the first step, 99.94% of lead was separated when evaporating at 800 ℃ for 1 h. Condensation products of pure lead were collected centrally, which eliminated the Pb contamination caused by its migration. The second step was optimized by the response surface methodology, and optimal operation parameters were determined as 1250 ℃ and 3 h. Under these conditions, 91.71% of copper was evaporated and transformed into nano-copper particles ranging from 20 nm to 200 nm. In short, this study firstly provided an effective approach for the treatment of waste glass diodes and their high-value-added reuse.

Revisiting the condensation reaction of lignin in alkaline pulping with quantitativity part III: predominant formation of α-β-type over α-5-type condensation product in soda cooking treatments of apocynol and creosol

Progress in the condensation of lignin is believed to interfere with delignification in alkaline pulping processes without any clear evidence, which motivated us to revisit it quantitatively. This study is the 3rd in the series which evaluates the condensation reactions of lignin in model systems of soda cooking processes using 4-(1-hydroxyethyl)-2-methoxyphenol (apocynol, Ap) and 2-methoxy-4-methylphenol (creosol, Cr). Ap was primarily converted to 2-methoxy-4-vinylphenol (vinylguaiacol, Vg) via the quinone methide intermediate to establish equilibrium before condensation reactions proceeded. Only the α-5-type condensation product between Ap and Cr (ApCr, 1-(4-hydroxy-3-methoxyphenyl)-1-(2-hydroxy-3-methoxy-5-methylphenyl)ethane) and the α-β-type condensation product between Ap and Vg or two molecules of Vg (ApVg, trans-1,3-bis(4-hydroxy-3-methoxyphenyl)but-1-ene) were identified without detecting any self-condensation products of Ap. The α-β-type condensation has not been well known and is an important finding of this study. The formation of ApVg was over 10 times faster than that of ApCr, which demonstrates that the α-β-type condensation is a major mode in soda cooking. However, because origins of α-β-type condensation substructures, such as C6-C2-type enol ethers, do not exist in native lignin, the results support our previous conclusion that the condensation reactions of lignin progress less frequently than previously believed.