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A composite based on Fe3O4 nanoparticles, graphene oxide, and a ionic liquid (1-butyl-3-methylimidazolium-2-carboxylate) is proposed as a sorbent for the extraction of bisphenol A (BPA) from bottom sediments by matrix solid-phase dispersion (MSPD). The saturation magnetization of the synthesized sorbent is 34 emu/g. Grinding of bottom sediments and subsequent grinding with a sorbent was carried out in a ball mill. Some stages of MSPD were partially automated, in particular, the procedures of magnetic separation, BPA desorption, and sorbent regeneration. The recovery of BPA under the experimentally selected conditions (sorbent mass 0.5 g, time required to grind the sorbent 5 min) was 94%. The sorbent can withstand four sorption-desorption cycles without a loss of sorption capacity. To purify the matrix from interferents, washing with n-heptane was proposed. Bisphenol A was determined by gas chromatography–mass spectrometry after derivatization with acetic anhydride. The analytical characteristics of the method were established using model samples of bottom sediments artificially contaminated with BPA. The limit of determination using the developed method is 0.1 μg/kg, the linearity range of the calibration curve is 0.3–12 μg/kg (r2 = 0.994). As real samples for analysis, we used bottom sediments selected near the discharge of wastewater treatment plants in the city of Voronezh (Voronezh River and Don River). The BPA concentration in bottom sediments is 3.83–6.52 μg/kg. [ABSTRACT FROM AUTHOR]

The aim of the current study is to modify water hyacinth fibre (WHF), which are then used to produce novel oil sorption polymers. Two synthetic materials were derived from acetylation by acetic anhydride using N-bromosuccinimide (NBS) as a catalyst and the graft co-polymerisation of butyl acrylate (BA) using 2,2′-azobisisobutyronitrile (AIBN) as an initiator. Physicochemical properties were comprehensively characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, contact angle, and thermogravimetric analysis. In the seawater/crude oil system, the best oil sorption capacity values of the raw WHFs and their acetylated-WHF and graft co-polymer WHF-g-BA were 7.46 g/g, 20.16 g/g, and 25.47 g/g, respectively. The sorption kinetic and isotherm studies exhibited that the oil sorption of the co-polymer WHF-g-BA is ruled by pseudo-second-order kinetic and Freundlich isotherm models. The reusability of the WHFs and their synthetic materials has reached 6 cycles of sorption/desorption, and this property of the co-polymer is always better than that of acetylated and original fibres. [ABSTRACT FROM AUTHOR]

A series of some new 1,3,4‐oxadiazole derivatives was synthesized. Hydrazide derivative 4 was reacted with some sugar aldehydes to give the corresponding sugar hydrazones 5 a–c. Acetylation of 5 a–c with acetic anhydride in pyridine, managed the per‐O‐acetyl derivatives 6 a–c while refluxing in acetic anhydride gave the corresponding 1,3,4‐oxadiazolines 7 a–c. On the other hand, 1,3,4‐oxadiazoles 8 a,b, 9, 10, 12, 14, and 15 were synthesized via the reaction of 4 with different reagents including p‐chlorobenzoic acid, nicotinic acid, methyl iodide, morpholine, phenyl isothiocyanate, potassium iodide, chloroacetyl chloride, and phosphorus oxychloride, respectively. The new compounds were assessed for their anticancer and antioxidant activities. Compounds 8 a,b, 10, and 12–15 displayed the most antioxidant activity. In addition, compounds 8 a, 8 b, and 13 showed strong cytotoxic activity. [ABSTRACT FROM AUTHOR]

The reaction of p-aminophenol with acetic anhydride under microwave irradiation in the presence of H-clinoptilolite was studied to continue the search for effective, economically favorable, and environmentally friendly methods for synthesizing acetaminophen (paracetamol). The proposed system, which provided a rapid synthesis of the most important drug with a high yield and purity, was demonstrated to be efficient. [ABSTRACT FROM AUTHOR]

Summary: Proteins are commonly used ingredients to impart certain non‐nutritional properties to foods. Consequently, the industry is constantly seeking to enhance proteins that provide these attributes to food products. Therefore, the aim of this research was to extract the protein from sesame seeds and evaluate the effect of chemical modification through acylation with lauroyl chloride and acetic anhydride on functional properties (solubility index, emulsifying, foaming, swelling and water‐holding and oil‐holding capacity). Chemical modification was successfully demonstrated using FTIR spectroscopy and X‐rays. It was found that acylation with lauroyl chloride or acetic anhydride altered the physicochemical and functional properties, particularly at pH 10. Both reactions exhibited substitution degrees exceeding 20%. Chemical modification via acylation resulted in significant improvements in water and oil retention capacity, emulsifying activity and foaming activity. Thermal analysis revealed significant changes in the modified samples, altering their denaturation temperature, leading to the conclusion that chemical modifications through acylation with lauroyl chloride or acetic anhydride offer benefits in certain functional properties relevant to the food industry. They also represent an opportunity to diversify the application of a by‐product obtained from sesame oil extraction. [ABSTRACT FROM AUTHOR]

This research investigates the enhancement effects of basalt fibers (BFs) and kraft lignin (KL) as natural additives on the mechanical properties of acrylonitrile–butadiene–styrene (ABS)‐based composites. Initially, BF was incorporated into ABS as a fiber reinforcement, and its mechanical properties were evaluated. It was observed that an increase in BF content in ABS led to an increase in the tensile strength while the impact strength tended to decrease. Subsequently, the potential of lignin or modified lignin as interfacial compatibilizers was assessed to improve the miscibility between ABS and BF. The modification of lignin was achieved via esterification by using esterifying agents (acetic anhydride [C2_Ac], propionic anhydride [C3_Pr], and butyric anhydride [C4_Bu]). At the optimal conditions (30 wt% of BF, 15phr of AcKL), the mechanical properties of ABS/BF/AcKL composite presented a 48.1% improvement in tensile strength and a 27.4% enhancement in impact strength compared to those of ABS/BF composite. The fracture surface analysis of the composite revealed that the esterified lignin enhances the compatibility between components, thereby filling the gaps present at the matrix‐fiber interface. These results suggest promising applications for multi‐component composite materials. [ABSTRACT FROM AUTHOR]

The reaction of ethyl pyridine-2-ylcarbamate with phenacyl bromides in acetonitrile gave 2-aryl-1-(ethoxycarbonyl)-2-hydroxy-2-phenyl-2,3-dihydro-1H-imidazo[1,2-a]pyridine-4-ium bromides which were con--verted into 2-arylimidazo[1,2-a]pyridines by heating in acetic anhydride, followed by treatment with potassium carbonate. [ABSTRACT FROM AUTHOR]

This paper presents a novel and reliable approach for the determination of tilmicosin residues in poultry muscle and pork via gas chromatography–tandem mass spectrometry after precolumn derivatization. The samples were subjected to a quick, easy, cheap, effective, rugged, and safe preparation method, solid-phase extraction, hydrogenation, gel chromatography separation, acid hydrolysis, and derivatization with pyridine and acetic anhydride. For the blank spiked samples at the limit of quantification, 0.5 times the maximum residue limit (MRL), the MRL, and 2.0 times the MRL, the recoveries were from 76.91 to 87.99% with a precision of 2.04–5.47%. The limits of detection and quantification were 2.3–4.4 and 6.2–9.8 µg kg−1, respectively. The protocol was validated and real samples analyzed to demonstrate its practical application. [ABSTRACT FROM AUTHOR]

Plastic film is widely produced and applied in many daily applications. Although it provides many benefits to human activity, the disposal of commercial plastics has always been a serious problem as it will contribute to landfilling issues and environmental pollution. Bioplastic film was invented to resolve part of this issue, as most of the plastic film produced from natural sources is biodegradable. However, the biodegradability and characteristics of the film are highly dependent on the type of raw material, production procedure, and chemical composition. In this study, extracted kapok cellulose was acetylated into cellulose acetate (CA) with various levels of acetic acid (17.5, 20, and 22.5 mL), acetic anhydride (5, 7.5, and 10 mL) and acetylation time (30, 45 and 60 min). The Box–Behnken design was applied to evaluate the quality of the produced film. The design showed that the level of acetic acid has a strong impact on CA's yield, acetic anhydride has a greater influence on tensile strength, and CA's solubility has a stronger connection with the acetylation time. All modeling equations developed were validated with the coefficient of determination, R2 more than 0.6. The optimized factor levels for the ductile-like film on acetic acid, acetic anhydride, and acetylation time are 20.530 mL, 9.546 mL, and 55.45 min, respectively. Whereas for brittle-like film, the optimized factor level is 22.399 mL, 10 mL, and 60 min, respectively. The ductility and brittleness of a plastic film can be modified by adjusting these level factors. [ABSTRACT FROM AUTHOR]

Sulfonamide compounds with functional group -SO2NH- show a wide range of biological activities and medicinal properties. The synthesis of sulfonamides has been of interest to medicinal chemists for a long time. In this article, the selective acylation of sulfanilamide with acetic anhydride was carried out using some catalysts with Lewis acid properties. In this research, the one-pot selective method of N-acylation of -SO2NH2 group in sulfanilamide molecule using stannous oxide nanoparticles as an efficient recyclable catalyst has been used. In this method, THF was replaced with expensive toxic amine solvents. The acylated product was identified by FTIR, 1HNMR, 13CNMR and MASS spectra. The best results with 85% efficiency, 95% selectivity were obtained using stannous oxide nanoparticles as catalyst (0.5 g) in tetrahydrofuran as solvent, at 60°C in 60 minutes. The catalyst was recycled three times and maintained its efficiency. Using this method is completely green and has economic and environmental benefits. [ABSTRACT FROM AUTHOR]

BACKGROUND: Collagen is a biomedical material with good biocompatibility, low toxicity, low immunoactivity, and high cellular affinity. However, the defects such as hydrophilicity and poor thermal stability are the key technical problems that need to be solved urgently in biomedical, tissue engineering, and other applications. OBJECTIVE: To elaborate on the preparation method, characterization, and application progress of acylated collagen. METHODS: PubMed, X-mol, and CNKI databases were used to search the literature on acylated collagen preparation methods, characterization, and application. The search time was from January 1992 to May 2023. The English search terms were “acylated collagen, modified collagen, water-soluble collagen, acetic anhydride”. Chinese search terms were “acylated collagen, modified collagen, water-soluble collagen”. After an initial screening of all articles according to inclusion and exclusion criteria, 53 articles with high relevance were retained for review. RESULTS AND CONCLUSION: (1) The preparation of acylated collagen is mainly obtained by the acylation reaction of acid anhydride, and the reaction sites are mainly ε-amino and N-terminus-amino of collagen, and the reaction environment of acylation reaction needs to be carried out in an alkaline environment. (2) Succinic anhydride is the preferred reactant of acylated collagen. Carbonic anhydride, citric anhydride, and bifunctional modifiers with acylation ability have been excavated in recent years to meet various requirements, but it is still limited to laboratory preparation; complex preparation process is difficult to industrialize, and follow-up research is needed to continuously improve. (3) The characterization methods of acylated collagen are similar to those of collagen, but there is still a lack of standards for the water-soluble characterization of acylated collagen. (4) In recent years, acylated collagen has been gradually used in the preparation of lenses, hydrogels, and dressings, as well as cosmetic raw materials. However, there is still little research on the application of acylated collagen, and there is a lack of complete in vivo experiments to verify the practicality of acylated collagen. [ABSTRACT FROM AUTHOR]

Diboradiazene compounds, derived in one step from the boron‐mediated reduction of dinitrogen (N2), were treated separately with sulfur and acetic anhydride, providing heterocyclic compounds that are BN isosteres of thiophene and 1,3‐oxazole, respectively. These simple reactions represent the final steps in two‐step routes to complex heterocycles from N2 that both circumvent the need for transition metal reagents and completely bypass the traditional intermediate ammonia. [ABSTRACT FROM AUTHOR]

BACKGROUND: Starch is the main component of quinoa seeds. However, quinoa starch has poor solubility in cold water and poor mechanical resistance and is easily aged, which limit its application. Therefore, modification of its structure to improve its functional properties is necessary. RESULTS: This research used acetic anhydride and sodium trimetaphosphate to modify the structure of starch molecules and investigated their influence on bread quality. The results showed that both esterification and crosslinking prevented the aggregation behavior of starch molecules. Moreover, they both decreased the gelatinization enthalpy change and relative crystallinity of the starch. Compared with native starch, modification significantly decreased the gelatinization temperature from 57.01 to 52.01 °C and the esterified starch exhibited the lowest enthalpy change with a 44.2% decrease. Modified starch increased the specific volume and decreased the hardness and chewiness of bread. Modification did not influence the moisture content in bread but impacted the water retention capacity, depending on the degree of modification. Low and medium degrees of modification improved the water retention capacity during storage. By contrast, a high degree of modification (10 g kg−1 crosslinking agent) decreased the water retention capacity. The dually modified quinoa starch (esterified and crosslinked) showed no influence on the textural properties of bread. CONCLUSION: This study demonstrated that both esterification and crosslinking significantly improved the functional properties of quinoa starch. Crosslinked or esterified quinoa starches have the potential to improve the textural properties of bakery products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The mechanochemical hydrogenation of 4-nitrophenol was examined in a ball mill reactor. Hydrogen gas flows through the reactor at ambient temperature and pressure in the presence of Pd/C catalyst and acetic anhydride. Under optimized conditions, simultaneous hydrogenation and acetylation in one pot increased paracetamol selectivity by avoiding undesirable side reactions of 4-aminophenol. Side product formation was further reduced through a novel bubbler configuration allowing for the delivery of acetic anhydride vapor to the reaction vessel. Ball mill results were compared to traditional stirred tank hydrogenations in a Parr reactor and shown to have superior yield and process mass intensity. [ABSTRACT FROM AUTHOR]

The significant medicinal and pharmacological facts about chromenes (benzopyran) nucleus prompted us to focus on constructing unique chromenes with biological value. New chromene derivatives 2–15 were synthesized, and their antibacterial effectiveness was studied. The reaction of the 2-amino-4H-chromene derivative 1 with a variety of reagents such as acetic anhydride, formic acid, chloroacetyl chloride, cyclopentanone, ethyl acetoacetate, diethyl malonate, aldehydes, and isatin produced derivatives 2–13. Compound 1 was also treated with aromatic amines such as p-toluidine and/or benzene-1,4-diamine with formaldehyde, yielding derivatives 14 and 15, respectively; spectral techniques were used to confirm the predicted structures of all compounds. The antibacterial activity of the recently synthesized compounds was assessed against two types of bacteria, Bacillus subtilis and Escherichia coli. There is encouraging antibacterial activity in compounds 5 and 7. [ABSTRACT FROM AUTHOR]

The main aim of this work was to study the role of the acetylation process of wheat straw pulp on its ability to rheologically modify two of the most important non-polar engineering fluid: bitumen and oil. Pulp was produced by a pilot-scale kraft pulping process from local wheat straw. Pulp was functionalized with acetic anhydride and sulfuric acid as a catalyst by modifying (temperature, pulp/acetic anhydride mass ratio, and reaction time. Further, chemical, morphological and thermal changes induced by the acetylation process were properly assessed. Acetylated wheat straw pulp dispersions in oil showed gel-like behaviour, with a mechanical spectrum characterized by higher values of the storage modulus (G′) and a minimum in the loss modulus (G″) at intermediate frequencies. The complex modulus (G*) for bitumen dispersions formulated with acetylated samples was up to 4 times higher than neat bitumen, and the phase angle (δ) indicated an enhancement in the elastic behavior parameters. The rheological response of these systems was associated with the microstructural network formed by pulp fibers and the balance between the physical and chemical changes of wheat straw fibers. According to the experimental results obtained, it can be concluded that acetylation is a relevant chemical treatment to modulate the rheological properties of wheat straw pulp dispersions in non-polar fluids, improving the compatibility between pulp fibers and these engineering fluids. Accordingly, this study provides valuable insights into the development of sustainable multiphasic materials (bitumen binders and semi-solid lubricants) for industrial applications. [ABSTRACT FROM AUTHOR]

A novel series of 1,3,4-oxadiazole derivatives of mefenamic acid was obtained by reacting hydrazones of mefenamic acid with anhydrous acetic anhydride. The mefenamic hydrazones were obtained by reacting different substituted aldehydes with mefenamic acid hydrazide. All the compounds were characterized by spectral data and elemental analysis. Molecular docking studies of all the compounds were performed against COX-1/COX-2 enzymes. Compound 4 and compound 10 were found to have the highest potential to bind with COX-1 while compound 3, compound 6, and compound 10 were found to have the highest potential to bind with COX-2 enzyme. [ABSTRACT FROM AUTHOR]

The objectives of this study are to investigate the structural and physicochemical properties of a novel acetylated lotus seed starch (LSA). LSA is successfully prepared using an aqueous phase method. Fourier transform infrared spectroscopy (FTIR) proves that a carbonyl C=O vibration at 1737 cm−1 are due to the introduced acetyl groups. X‐ray diffraction (XRD) indicates that the acetylation treatment does not change the crystal structure, but reduces the relative crystallinity of starch. Scanning electron microscopy (SEM) shows that the surface of LSA with 12% of acetic anhydride (LS‐12A) becomes the roughest. Moreover, compared with lotus seed starch (LS), the particle size, transparency, swelling power, and solubility of LSA are increased to 18.01 ± 0.66 µm, 15.30% ± 0.30%, 9.59 ± 1.78 g g−1, and 6.06% ± 0.99% at 55 °C with the additional content of acetic anhydride. However, differential scanning calorimetry (DSC) shows that the melting enthalpy of LSA decreases compared with LS. This work provides some theoretical basis for the study and development of acetylated starch. [ABSTRACT FROM AUTHOR]

This report expresses a sustainable methodology for the in situ synthesis of Ag nanoparticles (NPs) adorned carboxymethyl lignin (CML) functionalized Fe3O4 nanocomposite (Fe3O4@CML/Ag) and its subsequent chemical and biological applications. Structural and physicochemical features of such novel material was evaluated through a number of analytical techniques like FT-IR, FE-SEM, TEM, EDS, XRD, ICP and VSM. The nanomaterial was a competent catalyst towards the N-acylation of diverse amines using acetic anhydride at solvent-free conditions. The material was isolated by magnet and reused for 8 consecutive times. Furthermore, the material was employed in the biological evaluation of anti-oxidant properties by DPPH method as well as the anticancer studies of against HT-29 and Caco-2 colon cell lines following MTT method. The DPPH assay afforded a significant IC50 value that suggested the material to have good anticancer properties. Interestingly, % cell viability of the malignant cell lines was found to decrease dose-dependently over Fe3O4@NaLS/Ag nanocomposite. MTT assay afforded the corresponding IC50 values to be 395.4 μg/ml and 287.3 μg/ml respectively against the two cell lines. The absorbance rate was evaluated at 545 nm, which represented toxicity on normal cell line (CHO) even up to 2000 μg/mL. [ABSTRACT FROM AUTHOR]

BACKGROUND: Wheat bran is rich in dietary fiber (DF), particularly insoluble dietary fiber (IDF). Although the benefits for human health following the consumption of these DFs have been documented, the lower water retention capacity (WRC) and other properties still limit the applications of DF. Therefore, the current research investigated the impact of acetylation on the changes in the corresponding physicochemical and functional properties of DF. RESULTS: The current results indicated the acetylated group restricted the alignment of the molecular chains, which led to an increased amorphous phase in the fiber structure, followed by an enhanced thermal sensitivity and a reduced crystallinity as evidenced by X‐ray diffraction (XRD). Moreover, the acetylation of the IDFs enhanced the cholesterol absorption capacity, but the corresponding antioxidant capacity and cation exchange capacity were reduced, which might be due to the partial loss of the phenolic compounds onto the polysaccharides during the modification. Interestingly, a lower degree of substitution (DS) of the IDF achieved from water‐acetic anhydride modification led to a higher WRC and water swelling capacity (WSC). In contrast, a higher DS from acetic anhydride modification demonstrated a greatly improved in vitro hypoglycemic performance of the IDF, including α‐amylase inhibitory activity and glucose dialysis retardation index (GDRI), compared to the other samples. CONCLUSION: This study highlights a new approach to modify the functionality of IDFs via acetylation and the design of a novel IDF with hypoglycemic activity. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Acetylation is a wood modification used to increase the durability. Although it is known that the wood moisture content is lowered, the exact mechanisms behind the increased durability are not known. However, since fungi need water in different locations for different purposes the location and state of water is most probably of importance in addition to the total moisture content. In a previous study, we used targeted acetylation to alter the wood–water interactions in different parts of the wood structure in water saturated and hygroscopic moisture states. The main range for fungal degradation is, however, between these moisture ranges. This study investigated the effect of targeted acetylation on location, state and amount of water at non-saturated, high moisture states using the pressure plate technique. Specimens were modified using acetic anhydride by two approaches: (1) uniform modification (2) interface modification acting on the cell wall-lumen interface. They were then conditioned to eight moisture states between 99.64 and 99.98% relative humidity in both absorption and desorption and the location and state of water was studied using Low Field Nuclear Magnetic Resonance, X-ray computed tomography and Differential Scanning Calorimetry. Capillary water was present at all the included moisture states for all specimen types, but the amounts of capillary water in absorption were small. Increasing degree of interface modification increased the amount of capillary water compared to untreated wood. In addition, the uniformly modified wood often had higher amounts of capillary water than the untreated wood. The amount of cell wall water was decreased by uniform modification, but slightly or not reduced by the interface modification. The combination of targeted modification and conditioning to high well-defined moisture states thus gave very different amounts of capillary water and cell wall water depending on the conditioning history (absorption or desorption) and choice of modification. This opens new possibilities for designing materials and moisture states for fungal degradation experiments of wood. [ABSTRACT FROM AUTHOR]

A phosphine, base and additive free cross-coupling of arylboronic acid is reported via C–O bond cleavage of acetic anhydride using a switchable ferrocene functionalized n-heterocyclic carbene (NHC) palladium complex. The novel redox active catalytic system afforded the corresponding arylketones with good to excellent yields. [ABSTRACT FROM AUTHOR]

Drugs emerge in an endless stream; the global drug supply is increasing, and the number of drug users is steadily rising, so the detection of acetic anhydride, a raw material for drug preparation, is of great significance for controlling the spread of drugs. The crystal phase of semiconductor metal oxides has an important impact on oxygen vacancy, microscopic morphology, specific surface area, and high-energy surface exposure, which in turn affect the catalytic and gas-sensing effects of materials. Ion doping can sometimes achieve the purpose of changing the crystal phase. In this study, Cd-doped biphase (cubic phase and hexagonal phase) In2O3 nanospheres sensitive to acetic anhydride were synthesized via one easy hydrothermal process and the proportion of cubic phase and hexagonal phase is controlled by the amount of Cd element. The ion-doped biphase structure can save the consumption of expensive metals and provide a heterojunction structure as well as more oxygen vacancy to enhance gas sensing properties. The fabricated sensors not only have high sensitivity (372) to 100 ppm of acetic anhydride in the dry environment of 220 °C but also keep excellent selectivity and good stability. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) analysis, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used to observe the crystal phase, elemental information, nanoscale appearance, and existing state of the elements of the prepared compounds. The gas-sensitive mechanism was briefly analyzed according to the characterization information. The enhancing acetic anhydride sensing properties are owing to the change of internal electronic channels, abundant oxygen vacancy, and the crystal structure of In2O3 material caused by Cd doping. [ABSTRACT FROM AUTHOR]

Functionalized ionic liquids (FILs) are efficient ILs for the protection of various functionalities such as aldehydes, phenol, and alcohols with acetic anhydride under neat conditions. The attracted rising interest and the subject of active research in the field of catalysis is the variety of expanded applications and yet reports on ILs are still quickly increasing. This work reports a sulfonic acid functionalized ionic liquid is an environmentally friendly, easy handling, and reusable ionic liquid catalyst for the protection of aldehydes and phenols. The catalyst was characterized with different spectroscopic techniques which indicates the fabricated IL is matching with the reported methods. The catalyst can be recycled up to eight times without substantial loss in activity. Furthermore, no chromatographic separations were needed to obtain the desired products. [ABSTRACT FROM AUTHOR]

In this paper, we present the synthesis of new selenoloquinoxaline derivatives starting from 2‐chloroquinoxaline‐3‐carbonitrile 1. The compound 1 was subjected to a reaction with selenium metal in the presence of NaBH4 as a reducing agent in ethanol, under a nitrogen atmosphere. This reaction resulted in the formation of the sodium salt of 3‐cyanoquinoxaline‐2‐selenolate, which was subsequently reacted with α‐halogenated carbonyl compounds in situ. This reaction produced a series of newly synthesized 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐substituents. Ethyl 3‐aminoselenolo[2,3‐b]quinoxaline‐2‐carboxylate 3a was hydrolyzed by sodium hydroxide to give the corresponding sodium salt 9. This salt was then refluxed with acetic anhydride to produce oxazinone compound 10. The reaction of compound 10 with ammonium acetate afforded pyrimidoselenolo[2,3‐b]quinoxaline derivative 11. Compound 11 was then chlorinated using phosphorous oxychloride to give the corresponding chlorocompound. [ABSTRACT FROM AUTHOR]

This study was the first-ever attempt to apply MIL-68 (Ga) in developing an analytical method. The method extracts and preconcentrates some parabens from mouthwash and hydrating gel samples. The variable extraction parameters were optimized, and the figures of merit were documented. Avogadro software was used besides discussing intermolecular interactions to clarify the absorption process. ComplexGAPI software was also exploited to assess the greenness of the method. After the derivatization of the parabens using acetic anhydride in the presence of sodium carbonate, sodium chloride was added to the solution and vortexed to dissolve. A few milligrams of MIL-68 (Ga) were added into the solution and vortexed. Centrifugation separated the analyte-loaded absorbent, which was treated with mL volume of methanol through vortexing for desorption aim. A few microliters of 1,2-dibromoethane were merged with the methanolic phase and injected into a sodium chloride solution. One microliter of the extracted phase was injected into a gas chromatograph equipped with a flame ionization detector. High enrichment factors (200–330), reasonable extraction recoveries (40–66%), wide linear ranges (265–30,000 µg L−1), and appreciable coefficients of determination (0.996–0.999) were documented. The applicability of dispersive solid phase extraction for extracting polar analytes, imposing no additional step for performing derivatization, the capability of MIL-68 (Ga) for the absorption of both derivatized and non-derivatized parabens, the use of only 10 mg absorbent, and one-pot synthesis besides no high temperature or long reaction time in the sorbent provision are the highlights of the method. [ABSTRACT FROM AUTHOR]

In this research, the ionic liquid 4-methylpyridinium chloride grafted on nanoporous Ni/zeolite-Y was fabricated in several steps. Firstly, the nanocomposite of nickel-zeolite–Y (Ni@ZY) was prepared from the exchange-metal reaction of nickel (II) chloride with zeolite-NaY. This nanomaterial was then reacted consecutively with trimethoxysilyl propyl chloride and 4-methylpyridine to obtain nanocomposite of Ni/[(MPy)+Cl−]@ZY. Then, Fe3O4 nanoparticles were produced inside the functionalized zeolite pores with the use of ultrasonic waves to prepare a multi-functional and magnetically 4-methylpyridinium ionic liquid-nickel nanosystem (Ni/[(MPy)+Cl−]@ZY-Fe3O4). Its structure was identified and confirmed by various analyses including: FT-IR, FE-SEM, TEM, EDX, XRD, TGA, VSM and N2 adsorption–desorption (BET). To evaluate the catalytic performance, it has been successfully employed as a nanocatalyst, in facile Erlenmeyer synthesis of 4-arylidene-2-phenyl-5(4H) oxazolones (azlactones) through the multi-component reaction of benzoyl chloride, glycine, arylaldehydes and acetic anhydride under mild conditions. The presence of basic ionic liquid (4-methylpyridinium chloride), Lewis acid (Ni2+) on the solid surface of nanoporous (multifunctional) and the easy separation of the nanocatalyst from the reaction medium by an external magnet are the most distinguished advantages of this procedure. These points can be beneficial and effective in the catalytic processes. Some other advantages of the present process are high product yields, high-speed reaction rate, application of nanotechnology in the catalytic process, catalyst recyclability, low cost and non-toxicity. [ABSTRACT FROM AUTHOR]

Using salicylic acid and acetic anhydride as raw materials, silica gel as a catalyst, and microwave technology as an optimization method, the university organic chemistry teaching experiment of 'Preparation and Characterization of Acetylsalicylic Acid' was improved. Through the experiment, the impact of factors such as microwave power, reaction time, and raw material ratio on the final yield was explored. The optimal experimental conditions were determined as follows: silica gel with a particle size of 100-200 mesh, 0.25 g in quantity, 60 s reaction time, 70 °C reaction temperature, 500 W microwave power, and a molar ratio of acetic anhydride to salicylic acid of 2 : 1. The average yield was approximately 68.0%. Compared to the conventional heating method for the preparation of acetylsalicylic acid, microwave-assisted synthesis offers advantages such as simplicity, shorter reaction time, higher product yield, fewer impurities, and environmental friendliness. Introducing this microwave experiment into undergraduate organic chemistry laboratory teaching can broaden students' horizons, enrich experimental teaching content, and further improve the teaching level. [ABSTRACT FROM AUTHOR]

In order to improve process safety, product purity, and production efficiency in the synthesis of N-n-butyl-N-(2-nitroxy-ethyl)nitramine (BuNENA), a two-stage continuous flow microreactor system was constructed by sequentially connecting the self-designed heart-shaped channel microreactor and the caterpillar microreactor. n-Butylethanolamine was used as the raw material, nitric acid and acetic anhydride were used as the nitrating agents. The results showed that when the flow rate of n-butylethanolamine was 1.00 mL.min− 1, the temperature of the heart-shaped channel microreactor was 10 ℃, the temperature of the caterpillar microreactor was 35 ℃, the molar ratio of ZnCl2 to n-butylethanolamine was 2%, the molar ratio of nitric acid to n-butylethanolamine was 2.4, and the molar ratio of ZnCl2 to n-butylethanolamine was 2.4, the result was best. Under the conditions, the reaction time was shortened to 300 s, the purity of BuNENA was up to 98.1%, and the yield was 87.1%. [ABSTRACT FROM AUTHOR]

A new series of benzoquinoline-based heterocycles was synthesized utilizing the building block synthon, 2-((3-chlorobenzo[f]quinolin-2-yl)methylene)hydrazine-1-carbothioamide via the condensation of 3-chlorobenzo[f]quinoline-2-carbaldehyde with thiosemicarbazide. The titled thiosemicarbazone scaffold was conducted with some carbon-centered electrophilic reagents such as acetic anhydride, chloroacetyl chloride, chloroacetic acid, 2-bromo-1-(3-nitrophenyl)ethan-1-one, 2-chloro-N-phenylacetamide, and dimethyl but-2-ynedioate to achieve triazolethione, imidazolone, thiazolidinone, and thiazole derivatives. In turn, the hydrazinolysis of this substrate did not proceed as expected but it afforded the azine derivative. The antioxidant activity screening of the produced compounds revealed that thiazole and triazolethione derivatives were the most potent. [ABSTRACT FROM AUTHOR]

Hierarchical Beta zeolites with interconnected intracrystalline mesopores and high structural stability are highly attractive for catalytic applications involving bulky reactants. Here, by introducing a suitable amount of polydiallyldimethylammonium chloride into the initial synthesis system, micron-sized Beta zeolite crystals with abundant hierarchical porosity (Beta-H) were hydrothermally synthesized. The sample named Beta-H_1 exhibited very high catalytic activity and durability for the Friedel–Crafts acylation of anisole with acetic anhydride. A 92% conversion rate of acetic anhydride could be achieved after 1 h of reaction in a fixed bed reactor, and 71% conversion still remained after 10 h, much better than the rate for conventional Beta zeolite (which decreased rapidly from 85% to 37% within 10 h). The enhanced catalytic performance of Beta-H zeolites could be mainly attributed to the relatively lower strong acid density and the faster transport rate of the hierarchical zeolites. In addition, Beta-H showed high structural stability and could be easily regenerated via high-temperature calcination without obvious loss in catalytic activity, demonstrating its great potential for catalytic applications in the industrially important Friedel–Crafts acylation process. [ABSTRACT FROM AUTHOR]

Bimetallic cerium‐manganese modified Hβ zeolite sample (Ce/Mn‐Hβ) was prepared by ultrasonic assisted impregnation method and applied in nitration of toluene. The characterization results show that the active components (Ce and Mn) are successfully introduced into the framework of Hβ zeolite. The catalyst shows excellent catalytic activity and reusability for the nitration of toluene, giving high para selectivity. Under optimized conditions, it gives 68.7% selectivity to para‐nitrotoluene at 88.6% conversion over Ce/Mn‐Hβ in the presence of acetic anhydride (Ac2O). The theoretical calculations indicate that the Ce/Mn bimetallic active sites in modified Hβ zeolite can easily activate the nitrification reagent (AcONO2), and the enhancement of para selectivity is owing to the steric hindrance of catalyst. Furthermore, the reaction mechanism was proposed by the combination of experimental results and theoretical calculations. [ABSTRACT FROM AUTHOR]

To alleviate the global warming, it is necessary to transform carbon dioxide (CO2) into carbon monoxide (CO) through an expedient and resultful approach. In this work, a novel kind of Schiff base-cobalt ion complexes (CHE-Co) was constructed with 5-chorosalicylaldehyde, acetylglycine, acetic anhydride and CoCl3·6H2O as raw materials. It was discovered that CHE-Co exhibits outstanding photocatalytic activity to reduce CO2 to CO (selectivity: 91%) in an H2O/CH3CN solution (V:V = 1:4) under the irradiation of a LED-simulated solar lamp (λ > 400 nm, 90 mW cm–2). Under the optimized conditions, the yield of CO photo-catalytically reduced from CO2 can reach 15.92 μmol, with TON value of 1592 and TOF value of 159.2 h−1. The photo-catalytic mechanism of CHE-Co was proposed that CHE-Co with a positive Eonset can drive electrons shift from excited-state photosensitizer [Ru(phen)3]2+* to CHE-Co via a single-molecule rate control reaction. [ABSTRACT FROM AUTHOR]

Chemical modification of starch from the chayote root (Sechium edule Jacq) is carried out with lauric acid and acetic anhydride. The modified starch is characterized by Fourier‐transform infrared spectrometry (FTIR), X‐ray diffraction (XRD), and Differential Scanning Calorimetry (DSC) and used to formulate edible films. The developed edible films are characterized based on their physicochemical and mechanical properties. The physicochemical and functional properties of starch are affected by the incorporation of the acyl and acetyl group. Both starches exhibit a significant decrease in solubility. Starch modified by the incorporation of the acyl group (lauroyl) has higher thermal stability than starch modified by the incorporation of the acetyl group. The first shows an increase in emulsifying and foaming capacity, as well as water‐ and oil‐retention capacity, while the second exhibits adequate edible film‐forming properties. The edible films develop with modified starch with acetyl group has a homogeneous surface and exhibit a higher percentage of elongation at break when they are stored at a water activity of 0.561. In accordance with the above, it is concluded that the chayote root starch modified has physicochemical and functional properties that indicate their potential utility in the food industry. [ABSTRACT FROM AUTHOR]

The present work describes an efficient and convenient synthesis of a library of novel 1, 2-bis- (tetrasubstituted-benzylidene) hydrazine an analogue (3-7) 1,2-bis (3-methoxy-2-hydroxybenzlidene) hydrazine (3) and 1,2-bis (6-bromo-3-methoxy 2-hydroxybenzylidene) hydrazine (4), were obtained via opening of ester coumarin derivatives (1 and 2) with hydrazine hydrate under reflux. Diazotization of compound 4 with aryldiazonium chloride led to the formation of 1,2-bis (6-bromo-5-arylazo-3-methoxy-2-hydroxybenzylidene) hydrazine (6a,b). Acetylation of compounds 4 and 6a with acetic anhydride afforded the corresponding 1,2-bis (6-bromo-5-substituted-3-methoxy-2-acetoxy benzylidene) hydrazines (5 and 7). The cytotoxicity screening of some synthesized 1,2-bis (tetra substituted benzylidene) hydrazines (4-7) against breast cancer cell lines (MCF-7), and it was found several active compounds. Meanwhile compound 5 exhibited cytotoxic activity compared to reference drug. The DNA flow cytometry on MCF-7 cells of compound 5 was determined, it was found to cause G2/M phase arrest and induce apoptosis in all G1/M phases. In addition, compound 5 has been tested in other trials against aromatase inhibitors and tyrosinase inhibitors. [ABSTRACT FROM AUTHOR]

Objective: The present contribution describes a novel approach for obtaining steroid derivatives of the iso-type from sapogenins for drug discovery. Methodology: Diastereomeric 23-acetyl-spirostanols were prepared by acetolysis of smilagenin (4) (25R) using boron trifluoride diethyl etherate in acetic anhydride followed by treatment of the epimeric epoxycholestene obtained (6 or 9) under basic hydrolysis. Higher regioselectivity was attained in the presence of ZnCl2 in acetic anhydride. Results: Acetolysis of smilagenin (4) (25R) using boron trifluoride diethyl etherate in acetic anhydride afforded 20-α-methyl epoxycholestene 6 as the major product, two furostene derivatives (7 and 8), as well as the new 20-β-methyl epoxycholestene 9. Increased regioselectivity for the acetolysis of smilagenin (4) was observed using ZnCl2 in acetic anhydride affording 6 in 90% yield. Subsequent treatment of the epimeric epoxycholestene (6 or 9) under basic hydrolysis afforded two new diastereomeric 23-acetyl-spirostanols 14 and 15. The structures of all compounds were established using 1D and 2D NMR techniques. Conclusions: Formation of the two diastereomeric 23-acetyl-spirostanols (14 and 15) from epimeric epoxycholestenes 6 and 9 with KOH/EtOH proceeds with high stereospecificity. The configuration at C-20, C-22, C-23, and C-25 for the new iso-type 23-acetyl-spirostanol 15 was established by X-ray crystal analysis as 20R, 22R, 23S, and 25R. In addition to the above, the X-ray of 15 was analyzed and compared with the crystallographic data of sarsasapogenin acetate (16), smilagenin (4) and 23-acetyl-sarsasapogenin (17). [ABSTRACT FROM AUTHOR]

Formic acid, activated by acetic anhydride and a base, was employed as a CO surrogate to deoxygenate nitroarenes to nitrosoarenes, a reaction catalyzed by a palladium/phenanthroline complex in the homogeneous phase. Nitrosoarenes were trapped by conjugated dienes to give 3,6‐dihydro‐2H‐[1,2]‐oxazines. The latter were then transformed into N‐arylpyrroles employing CuCl as the catalyst. The reaction was designed to give the best results for pyrroles lacking any substituent in the 2 and 5 positions, which are difficult to produce employing most pyrrole syntheses. [ABSTRACT FROM AUTHOR]

The 2-[2-(1-(4-chlorophenyl)ethylidene]hydrazineyl-1,3-thiazolidin-4-one (V) compound was synthesized via the condensation of thiosemicarbazone derivatives (III) with chloroacetyl chloride which gave a 1,3-disubstituted thiourea derivative (IV) as an intermediate compound, this was followed by cyclization of (IV) in situ boiling ethanol solvent in the presence of anhydrous potassium carbonate. The treatment of thiazole derivative (V) with 4-hydroxybenzaldehyde yielded the corresponding 2,5-disubstituted-1,3-thiazolidin-4-one (VI). Compound (VI) was reacted with 4-chlorophenacyl bromide that afforded 5-(4-hydroxybenzylidene)-2-(1,2-disubstituted) hydrazineyl-1,3-thiazolid-in-4-one (VIII). Acetylation of compounds (VI) and (VIII) with acetic anhydride formed acetyl derivatives (VII) and (IX). The structures of synthesized compounds were characterized and confirmed based on spectroscopic methods and microanalytical method (elemental analysis). It was found that most of the 1,3-thiazole derivatives (V–IX) showed enzyme activity, while compound (VIII) exhibited an excellent activity with IC50 value (4.22 μM) for α-amylase. Also, compound (VIII) gave a good inhibitory activity against free radical scavenging (DPPH), DPP-4, and human breast cancer (MCF-7). Based on the achieved results, it was suggested that compound (VIII) acts as a vital structure for the development of the most potent α-amylase inhibitors. [ABSTRACT FROM AUTHOR]

Among oxygen-containing heterocyclic compounds such as coumarin and azacoumarin derivatives, the scaffold has become an important construction motif for developing new drugs. Coumarin and its derivatives possess many types of biological activities and have been reported to show significant cytotoxic activity. N-(6,8-disubstituted coumarin-3-yl)benzamides (8a-c) namely (3-N-(benzoyl) aminocoumarin-6-ylmethyl acetate (8a); N-[6-(1-acetylpyrazol-3-yldiazineyl) coumarin-3-yl] benzamide (8b); N-(8-methoxy-6-bromo-coumarin-3-yl) benzamide (8c), were synthesized via a cyclocondensation reaction of 5-(chloromethyl)-2-hydroxybenzaldehyde (3), 5-(pyrazol-3-yl-diazineyl)-2-hydroxybenzaldehyde (4), and 5-bromo-3-methoxy-2-hydroxybenzaldehyde (5) with N-benzoylglycine (7), in good yield. Treatment of compound 8c with ammonia in the presence of anhydrous potassium carbonate to yield N-(5-bromo-8-methoxy-1-azocoumarin-3-yl) benzamide (9). Compound (9) was acetylated with acetic anhydride to give N-(2-acetoxy-5-bromo-8-methoxyquinolin-3-yl) benzamide (10). N-(substituted coumarin and azacoumarin-3-yl) benzamides (8-10) were tested for their in vitro cytotoxic activity against (HepG2) cell line. Furthermore, DNA flow cytometry investigation over HepG2 cells indicated that compound 8a demonstrated arrest at G1/S stages of the cell cycle and induction of apoptosis by rising pre-G1 stage. Compound 8a displayed a significant tubulin polymerization inhibition. [ABSTRACT FROM AUTHOR]

This research is a continuation of the successful isolation of artocarpin from the root of Artocarpus kemando Miq reported in our previous study. In the previous study, the artocarpin was characterized with UV-Vis and FTIR techniques. In this follow-up investigation, the artocarpin was subjected to a transesterification reaction using acetic anhydride and pyridine as catalysts, and the product of the reaction was specified as compound 1. The compound 1 was further characterized with different techniques to gain more complete data and then tested for anticancer activity test against P-388 murine leukemia cells. Characterizations of the compound 1 using 1H-NMR and 13C-NMR techniques suggest that the modification reaction resulted in the conversion of the -OH groups at C2' and 4' at the artocarpin molecule to -OOCH3, and based on the MS analysis, the compound was proposed to have the molecular formula of C30H32O8. Another important feature of compound 1 that should be noted is the significant improvement in stability compared to the unmodified artocarpin. Anticancer activity tests against P-388 murine leukemia cells revealed that compound 1 has an IC50of 2.35 g/mL, confirming that the compound is categorized as an active anticancer agent and suggesting that the compound has promising potential that deserves further investigations. Doi: 10.28991/ESJ-2023-07-03-05 Full Text: PDF

ABSTRACTModified coir fiber improves compatibility between fiber and matrix. To explore a better fiber treatment approach and enhance the mechanical properties of composites, this study conducted alkali treatment and acetic anhydride treatment on long and short coir fibers. The effects of different treatments on the properties of coir fibers were characterized using TGA, FTIR, SEM, and stereomicroscopy, and the mechanical properties of the composites were tested. Results showed that the tensile strength of alkali-treated coir fibers (ACF) and acetic anhydride-treated coir fibers (AACF) were remarkably improved. Notably, ACF exhibited a significant 69% increase in tensile strength. The tensile strength of composites with alkali-treated long coir fibers (ALC) and composites with alkali-treated short coir fibers (ASC) reached 34.51 and 21.14 MPa, respectively. The highest flexural strength was found for the acetic anhydride-treated coir fibers, and the flexural strength of composites with acetic anhydride-treated long coir fibers (AALC) and composites with acetic anhydride-treated short coir fibers (AASC) reached 54.38 and 53.46 MPa, respectively. This study presents an improved methodology for enhancing the interfacial bonding ability between coir fibers and the matrix, consequently improving the properties of composites. It offers reference for the investigation of natural fiber composites.

Application of bioisostere plays an important role in drug discovery. α‐Aminoboronic acid is the familiar bioisostere of α‐amino acid. Developing reactions for the synthesis of a wide variety of α‐aminoboronic acid is one important task for synthetic chemistry. Herein, we report the development of nucleophilic C‐borylation chemistry for N‐arylimines catalyzed by nickel. The reaction proceeds through the insertion of a borylnickel species into the C=N bond to afford the corresponding α‐aminoboronate, which was isolated as acetamide after trapping with acetic anhydride. N‐Benzyl imine is also tolerated by the developed reaction. [ABSTRACT FROM AUTHOR]

The reaction of nicotinic and isonicotinic acid hydrazides with o-formyl benzoic acid in ethanol led to the formation of the corresponding hydrazones. It was found that o-formyl benzoic acid reacted in aldehyde form with hydrazides to form hydrazones. When heated in acetic anhydride, the latter are smoothly cyclized into 3-acetoxyisoindolin-1-ones. Structure of the synthesized compounds was proved by 1H and 13C NMR spectroscopy data. Antiradical and antiviral activity of the synthesized hydrazones and 3-acetoxyisoindolin-1-ones was studied. A compound with a wide spectrum of virus-inhibiting action against strains of the A virus was identified. [ABSTRACT FROM AUTHOR]

A flexible chitin nanofiber (ChNF) film with a thin fiber morphology, named, scaled-down (SD)-ChNF film, was previously found to be formed via successive partial deacetylation of the parent self-assembled ChNFs, cationization/dispersion via electrostatic repulsion in aqueous acetic acid, and suction filtration/drying. In this study, acetylation of a SD-ChNF film using acetic anhydride in pyridine was carried out to improve the mechanical properties. The FT-IR spectra of the acetylated SD-ChNF films suggested that acetylation progressed from the surface to the interior of the films with the increasing amounts of pyridine and elevating temperatures. The degrees of acetylation (DA) strongly affected the chitin crystallinity and surface morphology of the acetylated SD-ChNF films. Tensile testing of the acetylated SD-ChNF films indicated that the mechanical properties were improved by adjusting the DA values of the films. For example, the acetylated SD-ChNF film with an 1.84 DA value on surface showed values of 44.1 MPa and 24.9% for tensile strength and elongation at break, respectively. [ABSTRACT FROM AUTHOR]

The efficacy of human recombinant insulin can be affected by its aggregation. Effects of acetylation were observed on insulin structure, stability, and aggregation at 37 and 50 °C and pH of 5.0 and 7.4 with the use of spectroscopy, circular dichroism (CD), dynamic light scattering (DLS), and atomic force microscopy (AFM). Raman and FTIR results were indicative of structural changes in AC-INS, and CD analyses showed a slight increase in β-sheet content in AC-INS. Melting temperature (Tm) measurements indicated an overall more stable structure and spectroscopic assessment showed a more compact one. Formation of amorphous aggregates was followed over time and kinetics parameters showed a longer nucleation phase (higher t* amount) and lower aggregates amount (lower Alim) for acetylated insulin (AC-INS) compared to native (N-INS) in all tested conditions. The results of amyloid-specific probes approved the formation of amorphous aggregates. Size particle and microscopic analysis suggested that AC-INS was less prone to form aggregates, which were smaller if formed. In conclusion, this study has demonstrated that controlled acetylation of insulin may lead to its higher stability and lower propensity toward amorphous aggregation and has provided insight into the result of this type of post-translational protein modification. [ABSTRACT FROM AUTHOR]

The utilization of cellulosic fibers is becoming increasingly widespread worldwide as promising raw material in polymer composite reinforcement. However, and despite the multiple advantages of cellulosic fibers like the lower density, cheap cost and biodegradability, their use is limited due to hydrophilic character which reduces their affinity with hydrophobic matrices. A natural fiber treatment, whether chemical or physical, is advised to address this issue. The purpose of this study is to characterize the Ampelodesmos mauritanicus plant (AM) fibers extracted by the chemical method (2% NaOH for 48 h) and treated (chemically and physically). We carried out acetylation, mercerization and microwaves modification of the AM plant fibers to reduce their hydrophilic character. The influence of chemical and physical treatments on the structure and morphology of AM plant fibers was characterized by analytical techniques as per International Standard. X-ray diffraction confirmed that the AM fibers have a good crystallinity index (52.4%). Microwave physical treatment at 550 W increased their density from 1.00 to 1.55 g/cm3, their Young's modulus and tensile strength from 11.0 to 18.6 GPa and from 155 to 290 MPa, respectively, giving the highest values. It is followed by chemical treatments: first with acetic anhydride (C4H6O3) for 4 h and then with 3% NaOH also for 4 h. It should be observed that the data have a very considerable dispersion that calls for statistical analysis (method of Weibull with two and three parameters was utilized). [ABSTRACT FROM AUTHOR]

4-Quinolones are the structural elements of many pharmaceutically active compounds. Although several approaches are known for their synthesis, the introduction of an aryl ring in position 2 is problematic with most of them. The reductive cyclization of o-nitrochalcones by pressurized CO, catalyzed by ruthenium or palladium complexes, has been previously reported to be a viable synthetic strategy for this aim, but the need for pressurized CO lines and autoclaves has prevented its widespread use. In this paper, we describe the use of the formic acid/acetic anhydride mixture as a CO surrogate, which allows us to perform the reaction in a cheap and commercially available thick-walled glass tube without adding any gaseous reagent. The obtained yields are often high and compare favorably with those previously reported by the use of pressurized CO. The procedure was applied to a three-step synthesis from commercially available and cheap reagents of the alkaloid Graveoline. [ABSTRACT FROM AUTHOR]

The method for obtaining alkoxycarbonylmethyl esters of thioacetic acid, based on the interaction of mercaptoacetic acid esters with acetic anhydride in an alkaline medium was proposed. It showed that an alternative way to obtain alkoxycarbonylmethyl esters of thioacetic acid is the reaction of mercaptoacetic acid esters with acetyl chloride in the presence of equimolar quantities of triethylamine. The interaction of mercaptoacetic acid esters with benzoyl chloride in the presence of equimolar amounts of triethylamine was used to synthesize appropriate alkoxycarbonylmethyl esters of thioacetic and thiobenzoic acids. Study into synthesized compounds as additives to lubricating oils revealed that addition of butoxycarbonyl methyl ester of thioacetic acid at a concentration of 1% in M-8 oil practically eliminated its corrodibility, while butoxycarbonyl methyl esters of thioacetic and thiobenzoic acids also had some lubricating and antimicrobial properties. [ABSTRACT FROM AUTHOR]