Aromatic Carboxylic Acid Derivatives Research Articles

Synthesis, Characterization and Single Crystal X-ray Diffraction Analysis of Fused Triazolo/Thiadiazole Clubbed with Indole Scaffold

The present synthetic strategy involves the synthesis of indolyl-triazolo-thiadiazole heterocyclic ring systems 8–13 from the condensation of 4-amino-5-(1H-indol-2-yl)-3H-1,2,4-triazole-3-thione 1 with the aromatic carboxylic acid derivatives 2–7 in presence of POCl3 for 1 h. All compounds were obtained in very good yields and have been well-characterized using spectroscopic techniques. Exclusively, good quality crystals from the target organic hybrid 8-(1H-indol-2-yl)-5-(p-tolyl)-[1,2,4]triazolo [3,4-b][1,3,4]thiadiazole 9 were obtained and found suitable for X-ray single crystal diffraction measurement, which is used to confirm and analyze the molecular and supramolecular structure aspects of 9. The solid-state structure of the synthesized molecule 9 agrees very well with other characterizations. The packing of 9 is dominated by the N…H, S…H, C…C and S…C non-covalent interactions, which agree with the Hirshfeld surface analysis. The percentages of these contacts are calculated to be 20.3%, 5.4%, 9.4% and 4.3%, respectively.

Binary to ternary drug-drug molecular adducts of the antihypertensive drug ketanserin (KTS) with advanced physicochemical properties.

Focusing on a reliable supramolecular synthon approach, novel molecular salts of the antihypertensive medication ketanserin (KTS) with aromatic carboxylic acid derivatives (benzoic acid (BA), 2-hydroxybenzoic acid (2-HBA), and 2,5-dihydroxybenzoic acid (2,5-DHBA)) are reported. Binary salts of KTS with the respective salt former were obtained via solvent-assisted grinding followed by solution crystallization. Salt production was confirmed through crystal structure investigations that revealed proton transfer from the carboxylic acid group of the salt former to the piperidine nitrogen atom of KTS. A rigorous investigation of the crystal packing of novel binary salts of KTS inspired the construction of ternary adducts, and a ternary crystalline product was subsequently identified using milrinone (MLN), another cardiotonic drug. According to our knowledge, this is the first instance of a dual-drug ternary co-crystal combining both antihypertensive drugs. In order to evaluate the impacts of co-crystallization on the in vitro release behaviour of binary and ternary adducts, solubility tests for the cocrystal were carried out under a variety of physiological pH conditions. The results indicate that, in contrast to the parent drug and binary adducts, the solubility rate of the ternary adducts is significantly increased. Finally, the stability of the synthesised adduct was evaluated under a range of conditions, including temperature (40 ± 1 °C), humidity (90% ± 5% RH, 25 °C) and various solvents media, and it was established that they have good stability. We anticipate that the present findings will work with a wide range of medication combinations, providing a potential new approach to create multi-drug systems for cardiovascular disease.

Influence of core size on self-assembled molecular networks composed of C3h-symmetric building blocks through hydrogen bonding interactions: structural features and chirality.

The effect of the core size on the structure and chirality of self-assembled molecular networks was investigated using two aromatic carboxylic acid derivatives with frameworks displaying C3h symmetry, triphenylene derivative H3TTCA and dehydrobenzo[12]annulene (DBA) derivative DBACOOH, each having three carboxy groups per molecule. Scanning tunneling microscopy observations at the 1-heptanoic acid/graphite interface revealed H3TTCA exclusively forming a chiral honeycomb structure, and DBACOOH forming three structures (type I, II, and III structures) depending on its concentration and whether the system is subjected to annealing treatment. Hydrogen bonding interaction patterns and chirality were carefully analyzed based on a modeling study using molecular mechanics simulations. Moreover, DBACOOH forms chiral honeycomb structures through the co-adsorption of guest molecules. Structural diversity observed for DBACOOH is attributed to its relatively large core size, with this feature modulating the balance between molecule-molecule and molecule-substrate interactions.

Site-selective electrochemical carboxylation of aromatic C(sp2)–H bonds with CO2

We present a facile and economical method for synthesizing aromatic carboxylic acid derivatives through direct electrochemical C(sp2)–H carboxylation of (hetero)arenes with CO2. The reaction is carried out using a graphite felt anode and a nickel foam cathode in a user-friendly undivided cell setup under constant current conditions. Corresponding methyl carboxylates are obtained smoothly with good site-selectivity without the need of harsh chemical reductants or toxic transition metal catalysts. A cyclic voltammetry study was conducted, to distinguish between two potential mechanistic pathways. Additionally, nBu4NI was identified to serve as both electrolyte and anodic mediator. Notably, the methodology allows direct access to the desired product in a scale up manner.

Versatile Hydrogen-Bonded Assemblies of Twisted Tetra[3,4]thienylene Tetracarboxylic Acid with Selective Solvent Sorption

We demonstrated versatile hydrogen-bonded assemblies of a twisted π system with newly synthesized tetra[3,4]thienylene tetracarboxylic acid ThTCA. Due to its twisted saddle-shaped central π aromatic unit with an anisotropic arrangement of carboxyl units, a variety of dimensional solvate molecular crystals could be obtained, in contrast to typical aromatic carboxylic acid derivatives with low-dimensional assemblies. The versatile molecular assemblies could be converged to ThTCAdesol by desolvation with a simple annealing technique. ThTCAdesol showed selective solvent sorption behavior, which was governed by the solvent association energy and saturated vapor pressure. Especially, ThTCAdesol showed the selective sorption of EtOH, among primary alcohols.

Advances in self-assembly and regulation of aromatic carboxylic acid derivatives at HOPG interface

Aromatic carboxylic acid self-assembly has been a hot research field for many scientists due to its strong coordination ability and flexible coordination mode. The hydrogen bond formed between aromatic carboxylic acids is a strong intermolecular force and has directionality and saturation, which plays a very important role in the self-assembly and regulation of aromatic carboxylic acids. In this review, we introduce surface organization formed by aromatic carboxylic acids with the aid of scanning tunneling microscopy (STM). These two-dimensional structures include molecular templates, host-guest systems, and photo-isomerization structures. We also emphasize the thermodynamics and dynamics, which are important research topics of current and future study.

Ruthenium(ii)-catalysed selective C(sp2)-H bond benzoxylation of biologically appealing N-arylisoindolinones.

Site- and regio-selective aromatic C-H bond benzoxylations were found to take place using biologically appealing N-arylisoindolinones under ruthenium(ii) catalysis in the presence of (hetero)aromatic carboxylic acid derivatives as coupling partners. Besides the presence of two potential C(sp2)-H sites available for functionalization in the substrates, exclusive ortho selectivity was achieved in the phenyl ring attached to the nitrogen atom. Notably, the reactions occurred in a selective manner as only mono-functionalized products were formed and they tolerated a large number of functional chemical groups. The ability of the cyclic tertiary amide within the isoindolinone skeleton to act as a weak directing group in order to accommodate six-membered ring ruthenacycle intermediates appears to be the key to reach such high levels of selectivity. In contrast, the more sterically demanding cyclic imides were unreactive under identical reaction conditions.

Catalytic Wet Peroxide Oxidation (CWPO) of 2-Hydroxybenzoic acid and contaminated industrial effluent using LnMO3(Ln= La or Pr and M= Fe or Fe-Co)

The present study involves investigation of CWPO (Catalytic Wet Peroxide Oxidation) process for the removal of 2-Hydroxybenzoic acid (2-HBA or Salicylic acid), a moderate pollutant in industrial effluent. The best experimental conditions concerning selected varied parameters viz. pH, temperature were determined using hydrogen peroxide as oxidant in process. Different B-site substituted La and Pr based perovskite catalyst were synthesised via glycine combustion method. The structural analysis of the perovskite powders was monitored by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) was performed to analyse the morphology of solids. The images of SEM show distinct pores with particle size ranging between 50-280 nm. The results demonstrated CWPO of 2-HBA was largely influenced by B- site bimetallic catalyst (M = Fe-Co) at pH = 3.5, Cat[Conc.] = 20% and T = 100 °C, degrading 85-90% of the contaminant in 120 min, meanwhile for the B-site monometallic catalyst (M = Fe), the degradation was 80-88% under same reaction conditions. The catalytic performance of LnMO3(Ln = La or Pr and M = Fe or Fe-Co) was also performed for an industrial effluent. Presence of aromatic carboxylic acid derivatives in industrial effluent were confirmed by GC-MS analysis and were successfully degraded in the range of 80-85%.

3-Amino-1-methyl-1 H-pyridin-2-one-Directed PdII Catalysis: C(sp3)-H Activated Diverse Arylation Reaction.

A new bidentate directing group, 3-amino-1-methyl-1 H-pyridin-2-one, is introduced to achieve a powerful PdII metallacycle for selective γ-C(sp3)-H activation and arylation of aromatic and aliphatic carboxylic acid derivatives. The versatility of the directing group is validated for remote arylation of β-C(sp3)-H, β-C(sp2)-H, and γ-C(sp2)-H to achieve therapeutically important 2-pyridone analogues and arylated acid synthons. The traceless removal of the directing group to retrieve the directing element and carboxylic acids makes this method more interesting.

Synthesis of ortho-arylated/benzylated arylacetamide derivatives: Pd(OAc)2-catalyzed bidentate ligand-aided arylation and benzylation of the γ-C[sbnd]H bond of arylacetamides

In this paper, we report the Pd(OAc)2/AgOAc, bidentate ligand-directed CH functionalization of the sp2 γ-CH bond of arylacetamides. While, the bidentate ligand-directed site selective functionalization of the β-CH bond of aromatic carboxylic acid derivatives is well known, we herein, report our attempts on the Pd(II)-catalyzed, bidentate ligand-directed arylation, benzylation, alkylation, acetoxylation and hydroxylation of the sp2 γ-CH bond of the arylacetamide systems. The arylation and benzylation of arylacetamides were successful; however, the alkylation and acetoxylation/hydroxylation of arylacetamides were not successful. Various ligands were screened to substantiate the need for the bidentate ligand in the arylation/benzylation of arylacetamides, and 8-aminoquinoline was found to be the best bidentate ligand. Several substituted aryl-/heteroaryl iodides, 4-nitrobenzyl bromide and arylacetamide substrates were used to examine their reactivity pattern and accomplish the substrate scope/generality. In general, the bidentate ligand 8-aminoquinoline-directed arylation of arylacetamides gave the corresponding ortho-diarylated arylacetamides and benzylation of arylacetamides gave the corresponding ortho-mono benzylated arylacetamides as the predominant compounds. Overall, this method has led to the synthesis of new ortho-substituted arylacetamides in good to high yields.

An Easy Access to Construct Some New Fused 1,2,4‐Triazines with Ring Junction Nitrogen Systems and Their Biological Evaluation

The chemical reactivity of 4‐amino‐6‐benzyl‐3‐mercapto‐1,2,4‐triazine‐5(4H)‐one (1) towards various aliphatic or/and mono and bis aromatic carboxylic acid derivatives to give the corresponding fused heterocyclic systems, 1,3,4‐thiadiazoles 4, 5, 6, which incorporating 1,2,4‐triazine moiety was achieved. Moreover, compound 1 was subjected to reaction either with halo acetic acids or bromo ester to afford the respective fused nitrogen ring junction systems, thiadiazole 2 and 3 or thiadiazine 7. However, while the tetracyclic ring system 9 was furnished through condensation reaction of isatine with triazine 1. In addition, some of the new synthesized compounds were evaluated as an antioxidant and antitumor agents.

An Easy Access to Construct Some Fused 1,2,4‐Triazines with Ring Junction Nitrogen Systems and Their Biological Evaluation

The chemical reactivity of 4‐amino‐6‐benzyl‐3‐mercapto‐1,2,4‐triazine‐5(4H)‐one (1) towards various aliphatic or/and mono and bis aromatic carboxylic acid derivatives to give the corresponding fused heterocyclic systems, 1,3,4‐thiadiazoles 4, 5, 6, which incorporating 1,2,4‐triazine nucleus was achieved. Moreover, compound 1 was subjected to react either with halo acetic acids or bromo ester to afford the respective fused nitrogen ring junction systems, thiadiazole 2 and 3, or thiadiazine 7. However, the tetracyclic ring system 9 was furnished through condensation reaction of isatine with triazine 1. In addition, some of the new synthesized compounds were evaluated as an antioxidant and antitumor agents.

Photofunctional Eu3+/Tb3+ organic–inorganic polymeric hybrid microspheres with covalently bonded resin hosts

Abstract Novel organic/inorganic/polymeric hybrid microspheres are constructed with rare earth complexes into polymer matrix through covalent bonds. Functional covalent polymer linkages (abbreviated as PAAR(MR)-M1(M2, M3)) are achieved from the functionalization of three 4-substituted aromatic carboxylic acid derivatives (4-aminobenzoic acid (M1), 4-mercapto benzoic acid (M2), 4-hydroxybenzoic acid (M3)) with two polymer resins ( para -alkoxy-benzyl alcohol resin (PAAR) or Merrifield resin (MR)), which are through nucleophilic substitution reaction between amino (mercapto and hydroxyl) groups of M1 (M2,M3) and methyl chloride groups of PAAR (MR). Furthermore, ternary rare earth polymeric hybrid microsphere (abbreviated as PAAR(MR)-M1-3-RE-Phen) are constructed through coordination bonds with covalent polymer linkages and 1,10-phenanthroline (Phen) as ligands. The physical characterization and particularly the photoluminescence property of them are studied in detail, which present the regular microsphere morphology and characteristic photoluminescence.

A family of simple benzene 1,3,5-tricarboxamide (BTA) aromatic carboxylic acid hydrogels

We present the characterisation of a hydrogel forming family of benzene 1,3,5-tricarboxamide (BTA) aromatic carboxylic acid derivatives. The simple, easy to synthesise compounds presented here exhibit consistent gel formation at low concentrations through the use of a pH trigger.

ChemInform Abstract: Palladium‐Catalyzed Direct ortho‐Alkynylation of Aromatic Carboxylic Acid Derivatives.

AbstractThe aminoquinoline directing group promotes the ortho‐alkynylation without the need of any silver salts.

Palladium-Catalyzed Direct ortho-Alkynylation of Aromatic Carboxylic Acid Derivatives

The palladium-catalyzed direct alkynylation of C-H bonds in aromatic carboxylic acid derivatives is described. The use of 8-aminoquinoline as a directing group facilitates the alkynylation of an electronically diverse range of C(sp(2))-H bonds.

Synthesis, molecular docking study and antitumor activity of novel 2-phenylindole derivatives

The starting material, 4-(1-indol-2-yl)phenol 1 was obtained via Fischer synthesis. Vilsmeir Haack ’s formylation of 1 gave the carboxaldehyde derivative 2 which was subjected to different reactions affording the 3-substituted compounds 3– 10. Compound 1 reacted with halo esters to give 11 and 12a, b. The reaction of 12a with various amino derivatives gave compounds 13– 16. The hydrazide derivative 15a reacted with 1,3-diketones, ethyl acetoacetate and aromatic carboxylic acid derivatives to give 17a, b, 18 and 19a– e, respectively. Antitumor activity of target compounds were tested against breast cancer cell lines (MCF-7) and (MDA-MB-231). The most potent compound was 3e with IC 50 = 1.60 nM against (MCF-7). Docking was performed on colchicine binding site of tubulin to study the binding mode of the designed compounds.

Synthesis, characterization and potential application of monoacyl-cyclodextrins

Although the preparation of cyclodextrin (CD) monoesters with a variety of carboxylic acids has been already described in the literature, the direct regioselective CD acylation has proved to be critical, often requiring to be replaced with a more elaborate synthetic process. In this paper we describe the one-step preparation of several monoacylated CDs from acyclic or aromatic carboxylic acid derivatives. The ability of β-CD to enclose cupric ions in a sandwich-type manner was exploited to lead to high regioselectivity in the acylation of β-CD with benzoyl chloride, cinnamoyl chloride and phenyl acetyl chloride in water. Long chain aliphatic monoesters of α-, β- and γ-CD were best prepared in DMF. The results of our study showed that solvent and general conditions determined an overwhelming regioselectivity of acylation. 1H, 13C and 2D NMR experiments could easily discriminate the position of the ester. Monoacylated CDs were evaluated as a carrier of silibinin, the inclusion complexes were prepared and characterized by thermal analysis.

A New Route for the Synthesis of Linezolid Mimetic 3,4-Disubstituted Oxazolidin-2-one Derivatives

- New oxazolidin-2-ones (3), which mimic the clinically useful antibacterial agent (1) (Linezolid) were prepared by using a cyclization procedure with diethyl carbonate from aminoalcohol (7) starting with DL-serine methyl ester hydrochloride (4) and aromatic carboxylic acid derivatives (5).

Liquefaction of Corn Cobs with Supercritical Water Treatment

Corn cob powder was liquefied in a high-pressure reactor. The composition of the gas and liquid phases produced were analyzed. It was found that the yield of the gas phase and liquid phase increased, while the yield of solid residue decreased with increasing temperature. The gas phase was 33.4% to 49.15% (wt %), the liquid phase was 22.6% to 43% (wt %), and the solid phase was 23.6% to 28.25% (wt %) at 5 to 20 min. Liquid yield increased with the addition of potassium hydroxide. Total liquefaction yield decreased with the increasing of corn cob powder content. The gas phase consisted of hydrogen, carbon dioxide, carbon monoxide, methane, and a small amount of hydrocarbon. The liquid phase consisted of cyclic aromatic hydrocarbon, ketone, aldehyde, carboxylic acid, ester, nitrogenated compound, and related derivatives.