Carboxylic Acid Amides Research Articles

Synthesis of New Heterocyclic Derivatives from 4-(3, 5-Dimethyl-1-phenyl-1H-pyrazol-4-ylazo)- benzoic acid

In this work pyrazolin derivatives were prepared from the diazonium chloride salt of 4-aminobenzoic acid. Azo compounds were prepared from the reaction of an ethanolic solution of sodium acetate and calculated amount of active methylene compound namely, acetyl acetone to obtain the corresponding hydrazono derivative (1). Cyclocondensation reaction of compounds (1) with hydrazine hydrate and phenyl hydrazine in boiling ethanol affording the corresponding pyrazoline-5-one derivatives of 4-aminobenzoic acid (2,3). Then compound (3) was reacted with thionyl chloride to give the corresponding acid chloride derivative(4), followed by conversion into the corresponding acid hydrazide derivative (5) carboxylic acid thiosemicarbazide (11), esters (14,15), thioesters (16,17) and amides (18,19), when treated hydrazine hydrate, thiosemicarbazide, alcohols, alkylthiol and secondary amines in dry refluxing benzene; respectively. Schiff's bases (6-8) were prepared by refluxing of compound (5) with different aldehydes and ketons, then two compounds from the Schiff's bases were cyclized with ?-mercapto acetic acid to give (9 and 10). Furthermore, 1,2,4-triazole derivative (12) have been also prepared by refluxing thiosemicarbazide derivative with sodium hydroxide solution (4%) followed acidification of the result using (10%)hydrolic acid. Moreover, a thiadiazole derivative (13) has been prepared by treatment of thiosemicarbazide derivative with concentrated sulfuric acid as cyclyzing agent. Finally, oxadiazole derivative (20) has prepared by condensation of its acid hydrazide derivative with carbon disulfide in basic medium.

Single‐Pot Synthesis and Optimization of CCF@GO Nanocatalyst for Efficient Direct Oxidative Amidation of Carboxylic Acids and N,N‐Dialkylformamides

ABSTRACTIn this study, an efficient catalytic protocol using CuCoFe2O4@GO (CCF@GO) for the synthesis of amide bond (−CONH−) via direct coupling of carboxylic acids and N,N‐dialkylformamides is presented. The CCF@GO nanocatalyst has been synthesized via a single‐pot solvothermal method, by changing the proportions of copper and cobalt (1:1, 1:3, and 3:1). Catalyst screening, employing a model reaction with benzoic acid and dimethylformamide (DMF), revealed that the 1:1 proportion of CCF@GO catalyst exhibited excellent efficiency, achieving a high conversion (98%) towards amide formation. The enhanced catalytic efficiency observed in CCF@GO catalysts can be ascribed to the uniform distribution of active copper and cobalt species on the graphene oxide support, which possesses a high surface area. Optimization of the reaction was conducted by varying parameters such as temperature, solvent, catalyst loading, and oxidant. The prepared catalyst was characterized using various analytical techniques including XRD, FTIR, XPS, SEM, EDX mapping, and TEM. Furthermore, this heterogeneous nanocatalyst demonstrated recoverability using an external magnet and reused up to five times with just a modest loss of catalytic performance.

Potassium hexafluorotitanate as a catalytic activator for direct amidation of carboxylic acids

Described herein is the direct amidation of a range of carboxylic acids, in moderate to excellent yields, using potassium hexafluorotitanate (K2TiF6) as a catalytic activator. The ready commercial availability, low cost, and ease of handling of the catalyst, as well as the simple, chromatography-free work-up of the reaction renders the process very appealing.

Deoxyfluorinated Amidation of Carboxylic Acids Using Pyridinesulfonyl Fluoride

Deoxyfluorinated Amidation of Carboxylic Acids Using Pyridinesulfonyl Fluoride

Nucleophilic Functionalization of Tropylium Salts with Heterocyclic Amines and Carboxylic Acid Amides and Hydrazides

Nucleophilic Functionalization of Tropylium Salts with Heterocyclic Amines and Carboxylic Acid Amides and Hydrazides

A Simple and Cost-Effective FeCl3-Catalyzed Functionalization of Cellulose Nanofibrils: Toward Adhesive Nanocomposite Materials for Medical Implants.

In the present work, we explored Lewis acid catalysis, via FeCl3, for the heterogeneous surface functionalization of cellulose nanofibrils (CNFs). This approach, characterized by its simplicity and efficiency, facilitates the amidation of nonactivated carboxylic acids in carboxymethylated cellulose nanofibrils (c-CNF). Following the optimization of reaction conditions, we successfully introduced amine-containing polymers, such as polyethylenimine and Jeffamine, onto nanofibers. This introduction significantly enhanced the physicochemical properties of the CNF-based materials, resulting in improved characteristics such as adhesiveness and thermal stability. Reaction mechanistic investigations suggested that endocyclic oxygen of cellulose finely stabilizes the transition state required for further functionalization. Notably, a nanocomposite, containing CNF and a branched low molecular weight polyethylenimine (CNF-PEI 800), was synthesized using the catalytic reaction. The composite CNF-PEI 800 was thoroughly characterized having in mind its potential application as coating biomaterial for medical implants. The resulting CNF-PEI 800 hydrogel exhibits adhesive properties, which complement the established antibacterial qualities of polyethylenimine. Furthermore, CNF-PEI 800 demonstrates its ability to support the proliferation and differentiation of primary human osteoblasts over a period of 7 days.

Proline-derived carboxylic acid as a bifunctional organocatalyst for highly efficient asymmetric Michael addition of aldehydes to nitroalkenes

A novel bifunctional proline amide–carboxylic acid catalyst was used for the highly stereoselective Michael reaction of various aldehydes with different nitroalkenes. This catalyst was easily prepared using commonly available anhydrides and proline linked with a diamine spacer. The asymmetric catalytic Michael reactions afforded high yields (up to 98 %), diastereoselectivities (syn/anti ratio: up to 86:14), and enantioselectivity (up to 99 % ee) when 5 mol% of the catalyst is used with N-methylmorpholine as a base in a dichloromethane solvent at room temperature.

Determination of Erucamide Slip Additive in Polypropylene Masterbatch: Comparison of Soxhlet and Dissolution-Precipitation Method

Erucamide is a long-chain carboxylic acid amide used as a slip agent in plastic films. In this research, the slip additive in polypropylene masterbatch with 6% erucamide content was extracted by comparing two methods which are dissolution-precipitation and the Soxhlet method. The variant of sonication times in the dissolution-precipitation method and extractor-solvents in the Soxhlet method were done to determine the optimum parameter in each method. The examination of slip additive content in each extraction method used the KBr Disk-FTIR and the weight loss of sample analysis. The form of the sample, which was in the granule and powder form was also studied. Based on the result, the dissolution-precipitation method with 3 minutes of sonication times and the use of ethyl acetate as extractor solvent in the Soxhlet method gave a closer result for additive content in the masterbatch. The powder form of the sample also gave better results than the granule form for the extraction of erucamide. The Soxhlet method in the powder form showed comparable results with the dissolution-precipitation method by KBr Disk-FTIR analysis and higher results by weight loss analysis. By comparing the two methods of extraction, the Soxhlet method showed more robustness and efficiency for extraction of erucamide additive in polypropylene masterbatch than the dissolution-precipitation method.

Sensitivity of Plasmopara viticola to selected fungicide groups and the occurrence of the G143A mutant in Australian grapevine isolates.

Grapevine downy mildew, caused by Plasmopara viticola, is an economically important disease in Australia and worldwide. The application of fungicides is the main tool to control this disease. Frequent fungicide applications can lead to the selection of resistant P. viticola populations, which has negative impacts on the management of the disease. Identification of resistance and its prevalence is necessary to inform resistance management strategies. A total of 86 P. viticola isolates were collected between 2017 and 2022 from vineyards in 15 growing regions across Australia for four fungicide groups; phenylamide (PA, group 4), carboxylic acid amide (CAA, group 40), quinone outside inhibitor (QoI, group 11) and quinone outside inhibitor stigmatellin binding type (QoSI, group 45). Decreased phenotypic sensitivity was detected for all four groups, and resistance to metalaxyl-M (PA) and pyraclostrobin (QoI), was detected. Genetic analysis to detect the G143A (QoI) and G1105S (CAA) mutations using amplicon-based sequencing was performed for 239 and 65 isolates collected in 2014-2017 and 2017-2022, respectively. G143A was detected in 8% and 52% of isolates, respectively, with strong association to phenotypic resistance. However, G1105S was not detected in any isolates. Plasmopara viticola isolates in Australia with resistance to at least two fungicide groups have been detected, therefore it is necessary to adopt resistance management strategies where resistance has been detected. Vineyards should continue to be monitored to improve management strategies for downy mildew. © 2024 Society of Chemical Industry.

Toward a Practical Catalyst for Direct Amidation of Carboxylic Acids with Pyridine‐Borane Complexes

AbstractPyridine‐borane complex was widely used as a reducing agent, but the exploration of such reagent as a catalyst for amidation of carboxylic acids are still unknown. Here we reported the first example of direct amidation of carboxylic acids catalyzed by pyridine‐borane complexes. This protocol features a low catalyst loading (0.2–10 mol %), broad substrate scope, good functional group compatibility, and affording the amides in high yields.

Phytochemical analysis, GC-MS characterization and antioxidant activity of Hordeum vulgare seed extracts

Barley scientifically known as Hordeum vulgare (HV) is a major grain crop. Over the course of time, great interest has been developed in the usage of barley, because of its various pharmacological activities. Current study is designed to determine the chemical constituents of Hordeum vulgare (HV) seed extract by GC-MS technique, and Invitro antioxidant assays i.e. 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) and 2-azino-bis(3-ethyl benzthiazoline-6-sulfonic acid) (ABTS) methods. GC-MS identified 16 non-polar compounds in the hexane extract of HV plant, which includes carboxylic acid (6.25%), fatty acid (37.5%), carboxylic acid amide derivative of fatty acid (6.25%), triterpinoids (18.75%), fat soluble vitamin (6.25%), phytosterol (6.25%), stigmastanes (6.25%), beta diketones (6.25%), and cycloartenol (6.25%) respectively. The major compound includes Hexadecanoic acid, methyl ester (6.84%), n-Hexadecanoic acid (8.58%), 9,12-Octadecanoic acid (Z,Z)-, Methyl Ester (8.04%), 9,12-Octadecadienoic acid (Z,Z) (57.01%), Lup-20(29)-en-3-one (3.57%), γ-Sitosterol (3.31%). Some constituents such as Lup-20(29)-en-3-one, campesterol and squalene were observed and were not previously reported. Total phenolic and total flavonoid content were determined using spectrophotometric technique and calculated as gallic acid equivalents GAE/g dry weight and rutin equivalent RE/g of dry weight respectively.The highest phenolic content exhibited by the acetone extract of HV seedsi.e. 0.0597 mg GAE/g while the highest flavonoid content exhibited by dichloromethane extract i.e. 0.09 mg RE/g and 0.25 mg QE/g of dry weight respectively. All the extracts showed significant antioxidant activity in DPPH and ABTS cation decolorization assays. Methanol and dichloromethane extract showed the highest DPPH radical scavenging activity i.e. 52.41% and 42.07% at the concentration of 100 mg/ml respectively. Moreover, the IC50 has been determined by the acetone and methanol extract of HV seeds. The high antioxidant activity of its seed extracts has made this plant pharmacologically important. Conclusively, there is a vast scope to further explore the active principals of barley so that more of its pharmacological properties can be identified.

Chemoselective direct amidation of fatty acids with furfurylamine without coupling reagents in reversed micellar microenvironment

AbstractFuran heterocyclic compounds derived from renewable sources are popular versatile candidates for the production of multifunctional macromolecular materials. These compounds are also used as hydrophobilization monomers for reversible polyadducts or as versatile building blocks in Diels‐Alder reactions. In the present study, an efficient approach to chemoselective acylation of furfurylamine with a series of non‐preactivated monocarboxylic or dicarboxylic long‐chain fatty acids and some of their functionalized derivatives has been achieved via catalytic direct amidation in reversed micellar medium. A convenient and environmentally friendly method has been developed for furfurylamides via a dehydrative coupling reaction. For this purpose, a new cationic Brønsted‐type sulfonic acid catalyst containing a hexadecyl alkyl chain was synthesized and fully characterized. The present catalytic reaction produced the respective N‐furfurylamides materials in good to excellent yields. This study also confirms that the direct amidation of carboxylic acids with selected amine compounds can be successfully catalyzed by Brønsted acids. Its simplicity and high atom economy are the main advantages of this method.

Development of boronic acid catalysts for direct amidation of aromatic carboxylic acids using fluorescence-based screening.

Direct amidation of carboxylic acids with amines holds significant importance; therefore, catalytic processes involving boronic acids have undergone extensive investigation. However, studies focused on the amidation of aromatic carboxylic acids remain limited. In this study, we introduce a fluorescence-based screening methodology employing an anthracene derivative probe, facilitating the rapid evaluation of various amidation catalysts. Using this approach, boronic acids were evaluated for their catalytic potential. Our findings reveal that 2-hydroxyphenylboronic acid (C7), previously deemed inefficient for aliphatic acids, effectively catalyzes the amidation of aromatic acids. The catalysts identified through this method consistently achieved high yields, reaching up to 98% across a broad spectrum of substrates.

TiF4-catalyzed direct amidation of carboxylic acids and amino acids with amines.

Unlike other metal fluorides, catalytic titanium tetrafluoride enhances the direct amidation of aromatic and aliphatic carboxylic acids and N-protected amino acids in refluxing toluene. While aromatic acids were converted to amides with 10 mol% of the catalyst within 24 h, aliphatic acids underwent a faster reaction (12 h), with lower catalyst loading (5 mol%). This protocol is equally efficient with alkyl and aryl amines providing a variety of carboxamides and peptides in 60-99% yields.

Borylated cyclobutanes via thermal [2 + 2]-cycloaddition.

A one-step approach to borylated cyclobutanes from amides of carboxylic acids and vinyl boronates is elaborated. The reaction proceeds via the thermal [2 + 2]-cycloaddition of in situ-generated keteniminium salts.

Deoxyfluorinated amidation and esterification of carboxylic acid by pyridinesulfonyl fluoride.

Amide bond synthesis is one of the most used reactions in medicinal chemistry. We report an amide bond formation reaction through deoxyfluorinated carboxylic acids under mild conditions using 2-pyridinesulfonyl fluoride. The reaction procedure has been used in a one-pot synthesis of amides and esters via in situ generation of acyl fluoride. This one-pot synthetic method provides easy access to amides and esters. Using this method, we have sequentially synthesized a tetrapeptide and calceolarioside-B glycoside derivative with good yields.

Исследование реакции амидирования карбоновых кислот и их производных

The presented work shows the results of research in the field of studying the amidation reaction of carboxylic acids and their functionally substituted derivatives with various amines. The main patterns of the above reaction are shown, the mechanisms of reactions involving carboxylic acids, as well as their derivatives (esters, anhydrides and acid chlorides) are presented. The main areas of application of the synthesized amide products are considered. It is reported that the reaction of direct amidation of carboxylic acids with amine components can occur in the presence of various catalysts or auxiliary reagents, among which dicyclohexylcarbodimide is most often used. Direct amidation has been shown to be accelerated in the presence of nucleophilic reagents containing a free electron pair. Some features of the amidation reaction involving acid derivatives, in particular esters and acid chlorides, are also shown. It is noted that one of the variants of such reactions is the Schotten-Bauman reaction. The paper also describes the results of the authors’ own research. It is noted that condensation reactions of acid chlorides of some aliphatic, naphthenic and aromatic acids with amines of various structures have been carried out, leading to the formation of mono- and dicarboxyamide derivatives of heterocyclic compounds, such as benzimidazole, benzoxazole and oxadiazepine. The practical properties of the synthesized compounds were studied and it was found that their potassium salts have high biological activity and can be used as a growth stimulator for wheat and pea plants. In addition, it was shown that the resulting amides are corrosion inhibitors and some of them have highly protective effects and can be used in technology as inhibitors.

Boric Acid-Grafted Biochar (BoAB) for the Direct Amidation of Carboxylic Acids and Amines

Amidation is a key step in the development of numerous industrially and biologically relevant molecules, yet conventional methods often suffer from inefficiency and poor atom economy. In response, we introduce...

First examples of phosphoric anhydride mediated O- and N-acylation

It was shown that phosphoric anhydride can be used for the synthesis of esters and amides of carboxylic acids when they react with compounds containing hydroxyl and primary amino groups. A new method was proposed for obtaining paracetamol. An example of the reverse reactivity of these nucleophilic centers located in para -aminophenol molecule was revealed.

Ambient-Temperature, Metal-Free, CDI-Mediated Ex-Situ Conversion of Acids to Amides: A Useful Late-Stage Strategy.

An efficient ex-situ method for the amidation of carboxylic acids mediated by CDI has been disclosed herewith. This metal-free strategy is performed at ambient temperature and can be applied effectively for late-stage modification of amino acids and APIs.