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Background: Nitrite salts are frequently utilized as meat additives to improve the quality and safety of processed meat products. However, these salts are associated with the formation of carcinogenic nitrosamines. Given its potential regulating effect on the formation of intermediate molecules, such as nitric oxide, it is hypothesized that carnosine, a meat constituent possessing antioxidant activity and other multiple health benefits, could dampen the formation of nitrosamines. The current study therefore assessed the effect of carnosine on nitrosamine formation in both a monophasic aqueous system and a biphasic water–lipid system simulating a gastric environment. Results: In the monophasic system, relatively high levels of carnosine were required to significantly reduce the formation of different species of nitrosamine compared with the control (no carnosine). While higher levels of some nitrosamines were generated in both phases of the biphasic system, low carnosine concentrations significantly suppressed nitrosamine formation in the aqueous phase, while in the lipid phase, intermediate levels of carnosine were required. At higher carnosine levels, further reduction in nitrosamines was observed in the lipid phase. Conclusions: This study demonstrates the capacity of carnosine to reduce nitrosamine formation in aqueous and lipid environments and suggests the potential of dietary carnosine to lower the risks associated with the consumption of processed meat products. © 2024 His Majesty the King in Right of Canada and The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Reproduced with the permission of the Minister of Agriculture and Agri‐Food Canada. [ABSTRACT FROM AUTHOR]

Epoxy systems are essential in numerous industrial applications due to their exceptional mechanical properties, thermal stability, and chemical resistance. Yet, recycling epoxy networks and reinforcing materials in epoxy composites remains challenging, raising environmental concerns. The critical challenge is the recovery of well‐defined molecules upon depolymerization. To address these issues, an innovative strategy is developed utilizing imine‐containing secondary amine hardener (M1). The reaction of M1 with DGEBA produced high‐performance epoxy thermoset P1, which exhibits Young's modulus of 2.18 GPa and tensile strength of 63.4 MPa, and excellent stability in neutral aqueous conditions. Upon carbon‐fiber reinforcement, Young's modulus and tensile strength are significantly elevated to 10.99 GPa and 328.3 MPa, respectively. The reactive secondary amine functionalities enabled the tailored network to display a well‐defined growth pattern, yielding only well‐defined molecules and intact carbon fibers upon acidic depolymerization. Consequently, the recycled polymers retained properties identical to those of P1. Notably, it is discovered that despite the cross‐linked nature of the epoxy networks, complete dissolution in dichloromethane facilitated straightforward solvent‐based recycling, allowing the recovery of undamaged carbon fibers and an epoxy thermoset with properties matching the virgin material. Presented novel monomer design and approach showcased two important and efficient recycling options for epoxy systems. [ABSTRACT FROM AUTHOR]

Carnosine is a naturally occurring dipeptide that has been advocated by some authors as an interesting scaffold for the development of potential therapeutic agents in view of the positive outcomes of its supplementation in animal models of human diseases. Its mode of action seems to depend on the quenching of toxic electrophiles, such as 4–hydroxynonenal (HNE). However, carnosine's bioavailability in humans is lower than that in other mammals. The main reason for such an unfavorable pharmacokinetic profile is the activity of the enzyme human serum carnosinase (E.C. 3.4.13.20), which rapidly hydrolyzes carnosine upon absorption. Therefore, some studies have focused on the design of carnosinase-resistant derivatives that retain binding activity toward toxic electrophiles. Nevertheless, the structural modification of the N-terminus amino group of carnosine has rarely been considered, possibly because of its key role in the electrophile scavenging mechanism. This was proven, since some carnosine N-terminus modification generated inactive compounds, despite some derivatives retaining oral bioavailability and gaining resistance to carnosinase hydrolysis. Herein, we therefore report a study aimed at exploring whether the amino group of carnosine can be conveniently modified to develop carnosinase-resistant derivatives retaining the dipeptide activity toward toxic electrophiles. [ABSTRACT FROM AUTHOR]

Abstract A very practical method for the synthesis of unsymmetrical carbamide derivatives in good to excellent yield was presented, without the need for any catalyst and at room temperature. Using a facile and robust protocol, fifteen unsymmetrical carbamide derivatives (9–23) bearing different aliphatic amine moieties were designed and synthesized by the reaction of secondary aliphatic amines with isocyanate derivatives in the presence of acetonitrile as an appropriate solvent in good to excellent yields. Trusted instruments like IR, mass spectrometry, NMR spectra, and elemental analyses were employed to validate the purity and chemical structures of the synthesized compounds. All the synthesized compounds were tested as antimicrobial agents against some clinically bacterial pathogens such as Salmonella typhimurium, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Compounds 15, 16, 17, 19 and 22 showed potent antimicrobial activity with promising MIC values compared to the positive controls. Moreover, compounds 15 and 22 provide a potent lipid peroxidation (LPO) of the bacterial cell wall. On the other hand, we investigated the anti-proliferative activity of compounds 9–23 against selected human cancerous cell lines of breast (MCF-7), colon (HCT-116), and lung (A549) relative to healthy noncancerous control skin fibroblast cells (BJ-1). The mechanism of their cytotoxic activity has been also examined by immunoassaying the levels of key anti- and pro-apoptotic protein markers. The results of MTT assay revealed that compounds 10, 13, 21, 22 and 23 possessed highly cytotoxic effects. Out of these, three synthesized compounds 13, 21 and 22 showed cytotoxicity with IC50 values (13, IC50 = 62.4 ± 0.128 and 22, IC50 = 91.6 ± 0.112 µM, respectively, on MCF-7), (13, IC50 = 43.5 ± 0.15 and 21, IC50 = 38.5 ± 0.17 µM, respectively, on HCT-116). Cell cycle and apoptosis/necrosis assays demonstrated that compounds 13 and 22 induced S and G2/M phase cell cycle arrest in MCF-7 cells, while only compound 13 had this effect on HCT-116 cells. Furthermore, compound 13 exhibited the greatest potency in inducing apoptosis in both cell lines compared to compounds 21 and 22. Docking studies indicated that compounds 10, 13, 21 and 23 could potentially inhibit enzymes and exert promising antimicrobial effects, as evidenced by their lower binding energies and various types of interactions observed at the active sites of key enzymes such as Sterol 14-demethylase of C. albicans, Dihydropteroate synthase of S. aureus, LasR of P. aeruginosa, Glucosamine-6-phosphate synthase of K. pneumenia and Gyrase B of B. subtilis. Moreover, 13, 21, and 22 demonstrated minimal binding energy and favorable affinity towards the active pocket of anticancer receptor proteins, including CDK2, EGFR, Erα, Topoisomerase II and VEGFFR. Physicochemical properties, drug-likeness, and ADME (absorption, distribution, metabolism, excretion, and toxicity) parameters of the selected compounds were also computed.

Small molecular kinase inhibitors play a key role in modern cancer therapy. Protein kinases are essential mediators in the growth and progression of cancerous tumors, rendering involved kinases an increasingly important target for therapy. However, kinase inhibitors are almost insoluble in water because of their hydrophobic aromatic nature, often lowering their availability and pharmacological efficacy. Direct drug functionalization with polar groups represents a simple strategy to improve the drug solubility, availability, and performance. Here, we present a strategy to functionalize secondary amines with oligoethylene glycol (OEG) phosphate using a one‐pot synthesis in three exemplary kinase inhibiting drugs Ceritinib, Crizotinib, and Palbociclib. These OEG‐prodrug conjugates demonstrate superior solubility in water compared to the native drugs, with the solubility increasing up to 190‐fold. The kinase inhibition potential is only slightly decreased for the conjugates compared to the native drugs. We further show pH dependent hydrolysis of the OEG‐prodrugs which releases the native drug. We observe a slow release at pH 3, while the conjugates remain stable over 96 h under physiological conditions (pH 7.4). Using confocal microscopy, we verify improved cell uptake of the drug‐OEG conjugates into the cytoplasm of HeLa cells, further supporting our universal solubility approach. [ABSTRACT FROM AUTHOR]

The article discusses the synthesis and catalytic properties of Donor-Acceptor Stenhouse Adducts (DASAs). DASAs are triene substances that can be prepared using specific reagents and conditions. The study explores the use of Lewis acids as catalysts for transforming DASAs into their ring isomers, and suggests potential applications as photosensors and Lewis acid sensors. The document provides detailed experimental procedures and results for the synthesis and characterization of various compounds, as well as a general procedure for the one-pot cyclization of DASAs. [Extracted from the article]

Protocatechuic acid (PCA) is typically produced by microbial fermentation. Its separation from fermentation broth or aqueous waste streams is of great importance. This study aimed to recover PCA by a secondary amine namely di-n-octylamine (DOA). Three organic solvents, namely isobutyl methyl ketone, propyl acetate and linalool, were used with DOA. Important extraction parameters were optimised by response surface methodology. DOA/isobutyl methyl ketone system showed 95.84% extraction efficiency under the optimum conditions. The maximum E% of the DOA/propyl acetate system was 86.73%. The maximum E% of the DOA/linalool system was 81.71%. Additionally, a thermodynamic study was carried out, and the reactions were endothermic. [ABSTRACT FROM AUTHOR]

This review summarizes the recent studies on the synthesis of secondary amines by one-pot amination of aldehydes and ketones over heterogeneous catalysts. Amines are widely applied as the key intermediates in chemical industry for the synthesis of various commodities such as agrochemicals, drugs, detergents, lubricants, food-additives and polymers. Direct catalytic reductive amination of carbonyl compounds was considered which generally includes two steps: (i) formation of imines by interactions of aldehydes or ketones with amines, and (ii) subsequent hydrogenation of imines. Synthesis of secondary amines from carbonyl compounds and amines generated in situ under reaction conditions from their progenitors, e.g., respectively, alcohols or nitro-compounds, is also discussed in detail. Recent progress in application of hydrogen sources alternative to gaseous H2, such as formic acid, NaBH4, CO and water, favored development of metal-free catalysts including solid acid catalysts. The review addresses the scope of the amination reaction with aldehydes/ketones and nitro/amine compounds of different structure, the effect of the solvent, reaction conditions and catalyst properties. In addition, catalyst regeneration and reuse, kinetic regularities and kinetic modeling with an emphasis on the continuous mode of one-pot amination have been systematically summarized and discussed. It is suggested that the future work should focus on revealing the role of the catalytically active sites addressing their acid–base properties and the correlation between catalyst properties and the reaction performance, elucidating kinetic parameters and designing feasible reactor system for further industrial implementation. [ABSTRACT FROM AUTHOR]

• The CO 2 reaction heat was directly measured by a microcalorimeter. • The structure–activity relationship for CO 2 reaction heat by secondary amines was studied. • Mulliken's population analysis was used to study the charge distribution of N atom. • NCI and AIM were employed to study the weak interaction within the molecule. Developing amine solutions with low energy consumption is of great significance for CO 2 capture technology. Currently most of studies focused on reducing sensible heat and heat of vaporization by anhydrous absorbents and phase-change absorbents based on amines. It should be noted that CO 2 reaction heat of amines is also an important section for energy consumption. In this work, CO 2 reaction heat of 7 secondary amines was investigated aiming to reveal structure–activity relationship between CO 2 reaction heat and the length of the carbon chain, methyl side chain and hydroxyl group in secondary amines. The CO 2 reaction heat of 7 secondary amines was directly measured by microcalorimeter with high precision. Results showed that increasing the length of carbon chain, introducing hydroxyl group and removing methyl side chain in secondary amines could increase CO 2 reaction heat. The lengthening of carbon chain and the addition of the hydroxyl group led to an increase in the electronegativity in N atom of the secondary amines, thereby increasing the reactivity and reaction heat of the secondary amine. The steric hindrance caused by methyl side chain reduced the reactivity and reaction heat of secondary amine. This study could help to screen and develop energy-saving secondary amine absorbents for CO 2 capture. [ABSTRACT FROM AUTHOR]

An efficient and convenient one-pot two-step process for the regioselective synthesis of the novel tricyclic system 2-chloro-4-methyl-5,6-dihydrobenzo[b]pyrimido[5,4-f][1,4] oxazepine has been described via heterocyclization of 5-(chloromethyl)-2,4-dichloro-6-methylpyrimidine and 2-aminophenol under mild condition followed by reaction with the various secondary amine in moderate to good yields and short time (4a-f). [ABSTRACT FROM AUTHOR]

Direct understanding of the formation and crystallization of low-dimensional (LD) perovskites with varying dimensionalities employing the same bulky cations can offer insights into LD perovskites and their heterostructures with 3D perovskites. In this study, the secondary amine cation of N-methyl-1-(naphthalen-1-yl)methylammonium (M-NMA + ) and the formation dynamics of its corresponding LD perovskite are investigated. The intermolecular π-π stacking of M-NMA + and their connection with inorganic PbI 6 octahedrons within the product structures control the formation of LD perovskite. In an N,N-dimethylformamide (DMF) precursor solution, both 1D and 2D products can be obtained. Interestingly, due to the strong interaction between M-NMA + and the DMF solvent, compared to the 1D phase, the formation of 2D perovskites is uniquely dependent on heterogeneous nucleation. Nevertheless, post-treatment of 3D perovskite films with an isopropanol solution of M-NMAI leads to the exclusive formation of thermally stable 1D phases on the surface. The resulting 1D/3D heterostructure facilitates perovskite solar cells (PSCs) to not only achieve a record efficiency of 25.51% through 1D perovskite passivation but also significantly enhance the thermal stability of unencapsulated devices at 85 °C. This study deepens the understanding of the formation dynamics of LD perovskites and offers an efficient strategy for fabricating stable and high-performance PSCs., (© 2025 Wiley‐VCH GmbH.)

Direct and atom‐economical amidation of nonsteroidal anti‐inflammatory drugs naproxen ibuprofen and ketoprofen with a variety of secondary amines was effected using commercially available DCC under mild and open‐air conditions. These prodrug amides were obtained in good to moderate yields ranging between 30–90 %. [ABSTRACT FROM AUTHOR]

ο-benzoquinone is a common intermediate which is mostly formed by the oxidation of phenolics or polyphenols containing catechol structure. ο-benzoquinone has an outstanding nucleophilic ability, while advanced glycation end products (AGEs) are nucleophilic and can undergo a nucleophilic addition reaction with ο-benzoquinone to mitigate the harmful effects of AGEs on the body. As common nucleophilic substances, amino acids existing in large quantities in food processing and in vivo may bind competitively with ο-benzoquinone, thus influencing the trapping of ο-benzoquinone with AGEs. In this study, cyclic voltammetry and coexistence experiments were used to compare the reactivities of Nε-(carboxymethyl) lysine (CML) and amino acids with 4-methylbenzoquinone (4-MBQ). The results showed that CML is more reactive with ο-benzoquinone than most amino acids, and even in complex systems, ο-benzoquinone still captured CML. Moreover, almost all adducts were identified by UPLC-QTOF-MS/MS, and their chemical formulas were deduced. Quantum chemistry accurately predicts the efficiency and site of reactions of ο-benzoquinone and nucleophiles to a certain extent, and found that a secondary amine has a greater reactivity with 4-MBQ than a primary amine in a similar molecular structure. In general, ο-benzoquinone could capture AGEs, thereby showing potential to reduce the harmfulness of AGEs. [ABSTRACT FROM AUTHOR]

The synthesis of multi‐substituted electron‐deficient alkenes is often accomplished via cross‐coupling of diazo compounds in the presence of a metal catalyst. Herein, we report an organocatalytic protocol that enables the direct coupling of aliphatic aldehydes with sulfonium ylides. A key carbene mimetic, α‐iodoenamine/enol, is believed to engage in direct cross‐coupling with a sulfonium ylide, delivering α,β‐unsaturated carbonyl compounds with a formyl substituent. The reaction demonstrated remarkably mild conditions, convergence, and control of olefin geometry. [ABSTRACT FROM AUTHOR]

Herein, we describe the synthesis of 3-[N-(4-methoxybenzyl)amino]benzo[de]anthracen-7-one via a two-step procedure including 3-aminobenzanthrone condensation with anisaldehyde and following reduction of obtained imine to appropriate amine by sodium borohydride. The structure of the synthesized compounds was established by elemental analysis, nuclear magnetic resonance spectroscopy, mass spectrometry (EI-MS), and infrared spectroscopy (FT-IR) and confirmed by single-crystal X-ray diffraction. The title compound was analyzed by thermal gravimetric analysis, UV/vis, and fluorescence spectroscopy.

The crystal structure of the title compound, C10H13N·3H2O, a heterocyclic amine, was determined in the presence of water. The compound co-crystallizes with three water molecules in the asymmetric unit, which leads to the formation of hydrogen bonding in the crystal.

The title compound, C15H15NO4·C3H7NO·H2O, a secondary amine molecule, is accompanied by one equivalent of water and one equivalent of dimethylformamide (DMF) as solvents. The molecule is non-planar, with a Caryl—CH2—NH—Caryl torsion angle of −66.3 (3)°. In the crystal, O—H...O and N—H...O hydrogen-bonding interactions between the amine molecules and the two types of solvent molecule result in the formation of a layered structure extending parallel to (010).

Tetraazamacrocycle such as 1,4,7,10-tetraazacyclododecane "cyclen" are known for efficient complexation of metallic ions and were used as an ionic recognition agents in chemical sensors in aqueous medium.The aim of this paper is to examine in more detail the oxidation mechanism of amines in cyclen before copper complexation and after copper complexation. Gold electrodes modified with mono-N-MNCyclen(mono methyl-naphtyl-cyclen) and tetra-N-MNCyclen thin films were obtained by deposition of mono-N-MNCyclen and the tetra-N-MNCyclensynthesized respectively by bisaminal route in three steps (protection, N-mono-alkylation and deprotection) and direct route. The comparative study of the electrochemical oxidation of amines in both cyclens allowed the identification of the tertiary and of the secondary amines. From the potential-pH relation and the variation of the intensities of the oxidation peaks, the redox mechanisms of both types of amines was proposed. The electrochemical redox behaviour of the amines in the copper-mono-N-MNCyclen complex was studied. From the potential-pH relation and the variation of the intensities of the oxidation peaks, the redox mechanisms of amines and the structure of the copper-mono-N-MNCyclen complex were proposed. The intensities of the oxidation peaks of the amines vary linearly with the copper concentration, in the range 10−12 M to 10–6 M, leading to a detection limit of of 1 pM of Cu2+. [ABSTRACT FROM AUTHOR]

Iron-based catalysts have been widely used in N-alkylation of amines with alcohol using borrowing hydrogen strategy, due to low toxicity and cost. Herein, based on Saito and co-workers’ experiment, we discuss a possible mechanism for N-alkylation of secondary amines with alcohol under an iron-based catalyst using DFT calculations. Contrary to N-alkylation of primary amines, only one hydrogen on alcohol benzyl group is taken by the iron-catalyst during radical transfer process. Thus, instead of forming an imine, a structure with a radical is formed. Overall, there are three parts to this mechanism: 1) hydrogen borrowing by the iron-based catalyst; 2) radical addition; 3) hydrogen reduction. There are two possible pathways of hydrogen borrowing: either by a distal oxygen or by the oxygen directly coordinating with iron. According to the computed free energy barrier, the former one is more favorable. We also found four possible pathways of radical addition. Our calculations suggest a direct dehydration step with short steps and lower energy barrier was more favorable. [ABSTRACT FROM AUTHOR]

We reported an efficient one-pot two-step synthesis of 3-(tert-butyl)-N-(4-methoxybenzyl)-1-methyl-1H-pyrazol-5-amine 3 in good yield by a solvent-free condensation/reduction reaction sequence starting from 3-(tert-butyl)-1-methyl-1H-pyrazol-5-amine 1 and p-methoxybenzaldehyde 2. The one-pot reductive amination proceeded by the formation in situ of the N-(5-pyrazolyl)imine 4 as key synthetic intermediate of other valuable pyrazole derivatives. This methodology is distinguished by its operational easiness, short reaction time, isolation and purification of the aldimine intermediate is not required. The structure of the synthesized N-heterocyclic amine 3 was fully characterized by FTIR-ATR, 1D and 2D NMR experiments, EIMS, and elemental analysis.

In the crystal of the title vanilline derivative, 2C15H15NO4·H2O, the secondary amine molecule is accompanied by half equivalent of water. The molecule is non-planar, with torsion angle Caryl—CH2—NH—Caryl of −83.9 (2)°. In the crystal, the system of O—H...O hydrogen bonds, including bridging water molecules residing on crystallographic twofold axes, results in a two-dimensional layered structure. Within the layers, there are also weak N—H...π interactions involving the vanilline benzene ring.

ο-benzoquinone is a common intermediate which is mostly formed by the oxidation of phenolics or polyphenols containing catechol structure. ο-benzoquinone has an outstanding nucleophilic ability, while advanced glycation end products (AGEs) are nucleophilic and can undergo a nucleophilic addition reaction with ο-benzoquinone to mitigate the harmful effects of AGEs on the body. As common nucleophilic substances, amino acids existing in large quantities in food processing and in vivo may bind competitively with ο-benzoquinone, thus influencing the trapping of ο-benzoquinone with AGEs. In this study, cyclic voltammetry and coexistence experiments were used to compare the reactivities of Nε-(carboxymethyl) lysine (CML) and amino acids with 4-methylbenzoquinone (4-MBQ). The results showed that CML is more reactive with ο-benzoquinone than most amino acids, and even in complex systems, ο-benzoquinone still captured CML. Moreover, almost all adducts were identified by UPLC-QTOF-MS/MS, and their chemical formulas were deduced. Quantum chemistry accurately predicts the efficiency and site of reactions of ο-benzoquinone and nucleophiles to a certain extent, and found that a secondary amine has a greater reactivity with 4-MBQ than a primary amine in a similar molecular structure. In general, ο-benzoquinone could capture AGEs, thereby showing potential to reduce the harmfulness of AGEs.

A non-noble metal-based bifunctional Fe–Ni/MMT nanocomposites exhibit excellent H 2 generation capability from the methanolysis of NaBH 4 at a rate of 16,200 mL min−1 g−1 Fe – Ni with 10%Fe–Ni loading on MMT support. Moreover, the evolved H 2 from this catalytic process is efficiently utilized for the one-pot step-wise synthesis of secondary amines from nitrobenzene and aldehydes using NaBH 4 as a source of hydrogen at room temperature. Circumventing the reduction of aldehyde and triggering the formation of imine intermediate through sequential addition of reactants in a time dependent manner has resulted in the excellent yields for aliphatic, aromatic and heterocyclic amines (91–98%). The catalytic activity of Fe–Ni/MMT nanocomposite is ascribed to synergic association of Fe–Ni NPs, Lewis and Brønsted acidity as well as adsorptive nature of MMT. Thus, a simple, facile and greener route is developed for the synthesis of secondary amines with an efficient H 2 generation non-noble metal catalyst and easily accessible H-donor at room temperature. A simple, facile and cost-effective methodology is developed for efficient H 2 evolution and one-pot synthesis of secondary amines from nitrobenzene and aldehyde with non-noble metalbased Fe–Ni/MMT catalyst using NaBH 4 at room temperature. Image 1 • Fe-Ni/MMT exhibit excellent H 2 generation rate of 16,200 mL min−1g−1 Fe–Ni at RT. • Substantially lower energy of activation for the methanolysis of NBH 4. • One-pot cascade synthesis of secondary amines from nitrobenzene and aldehyde. • Reduction, condensation and further reduction occurs in a time-dependent manner. • Simple and cost-effective methodology with non-noble metal catalyst. [ABSTRACT FROM AUTHOR]

Chiral p -phenylene-based dicarboxamides featuring carboxamide and 2-arylacrylamide motifs were synthesised through a synthetic sequence involving conventional organic reactions followed by palladium-catalysed aminocarbonylation. 4-Iodoacetophenone was used as starting material to prepare to 1',4-diiodostyrene, which underwent several aminocarbonylation reactions, using in situ formed palladium-phosphine catalysts and various biologically relevant amines as N -nucleophiles such as, amino acid esters, nortropine, and aminoandrostane derivatives. By exploring the remarkable difference in reactivity between the iodoalkene and iodoarene functionalities, the aminocarbonylation of the iodoalkene moiety was carried first with high chemoselectivity, followed by sequential transformation of the iodoarene functionality into the corresponding carboxamide using a different nucleophile. This approach allowed us to obtain a range of otherwise challenging chiral dicarboxamides, in moderate to high isolated yields through highly chemoselective reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, C10H13N·3H2O, a heterocyclic amine, was determined in the presence of water. The compound co-crystallizes with three water molecules in the asymmetric unit, which leads to the formation of hydrogen bonding in the crystal. [ABSTRACT FROM AUTHOR]

This study investigated the transformation of secondary amine pharmaceuticals in UV-C/NO 3 − and in nitrate-rich wastewater at 254 nm by taking diclofenac, diphenylamine, mefenamic acid and furosemide as probe compounds. The degradation of targeted compounds were positively related to nitrate concentration and mainly caused by the formation of peroxynitrite and related reactive nitrogen species (e.g., nitrogen oxide and nitrogen dioxide radicals). Major transformation products were identified to provide fundamental understanding of the selective oxidation of secondary amine with reactive nitrogen species. UV photolysis, hydroxyl radical oxidation, nitration and nitrosation processes were found to be the most significant transformation pathways. In case of diphenylamine, for which most of the identified intermediates were available as standard, the relative significance of each transformation route could be established, highlighting for the first time the important role of N-nitrosation processes in UV/NO 3 − treatment followed by the decomposition of the resulting N-nitroso compounds by an alpha hydroxylation mechanism. This specific transformation pathway was of concern because it constitutes the molecular basis of N-nitrosamine carcinogenicity and may contribute to the increase in effluent genotoxicity under UV-C treatment in addition to the formation of nitrophenols. Hydrogenocarbonate ions at concentration values higher than 300 mg/L appeared to be a protective specie against nitrosation processes due to the formation of carbamate adducts but H 2 O 2 in UV-C/H 2 O 2 could be responsible for an exacerbation of the N-nitrosation pathway due to an addition source of hydroxyl radical in the system. The occurrence of major transformation products of diclofenac was confirmed in nitrate-rich wastewater under UV-C treatment at pilot-scale operation. Image 1 • Secondary amine pharmaceuticals are readily phototransformed in UV-C/NO 3 − • Reactive nitrogen species play a key role in amine phototransformation. • N-nitrosation was the transformation route of the highest concern. • HCO 3 − limits nitrosation processes due to the formation of carbamate adducts. • Pilot-scale validation of diclofenac transformation route in nitrate-rich wastewater. [ABSTRACT FROM AUTHOR]

The title compound, C15H15NO4·C3H7NO·H2O, a secondary amine molecule, is accompanied by one equivalent of water and one equivalent of dimethylformamide (DMF) as solvents. The molecule is non-planar, with a Caryl--CH2-- NH--Caryl torsion angle of -66.3 (3)°. In the crystal, O--H···O and N--H···O hydrogen-bonding interactions between the amine molecules and the two types of solvent molecule result in the formation of a layered structure extending parallel to (010). [ABSTRACT FROM AUTHOR]

Proline was reported to improve sperm quality in rams, stallions, cynomolgus monkeys, donkeys, and canines during cryopreservation. However, the underlying mechanism remains unclear. The aim of this study was to investigate the effect of proline on boar semen during liquid storage at 17 °C and explore the underlying mechanism. Freshly ejaculated boar semen was supplemented with different concentrations of proline (0, 25, 50, 75, 100, 125 mM) and stored at 17 °C for nine days. Sperm motility patterns, membrane integrity, ATP (adenosine triphosphate), reactive oxygen species (ROS), and GSH (glutathione) levels, and the activities of catalase (CAT) and superoxide dismutase (SOD) were evaluated after storage for up to five days. It was observed that boar sperm quality gradually decreased with the extension of storage time, while the ROS levels increased. Addition of 75 mM proline not only significantly improved sperm membrane integrity, motility, and ATP levels but also maintained the redox homeostasis via increasing the GSH levels and activities of CAT and SOD. When hydrogen peroxide (H2O2) was used to induce oxidative stress, addition of proline significantly improved sperm quality and reduced ROS levels. Moreover, addition of proline also improved sperm quality during the rapid cooling process. Notably, addition of DL-PCA (DL-pipecolinic acid) rescued the reduction of progressive motility and total motility caused by H2O2, and THFA (tetrahydro-2-furoic acid) failed to provide protection. Furthermore, addition of proline at 75 mM increased the activity of proline dehydrogenase (PRODH) and attenuated the H2O2-induced reduction in progressive motility. These data demonstrate that proline protects sperm against oxidative stress through the secondary amine structure and proline dehydrogenase-mediated metabolism.

1-(Substituted-1-ylmethyl)indoline-2,3-dione 1a-c have been synthesized from different types of secondary amine with isatin and formaldehyde in alcohol. The compound 1 have then been converted to the respective compound 2a-g (Z)3-(4- subsitutedphenylimino)-1-(substituted-1-ylmethyl)indolin-2-one by treatment with different types of primary amines. Interaction of compound 2 with thioglycolic acid and chloro acetyl chloride results in cyclization to give compound spiro isatin derivatives compounds 3a-g. The anti-microbial activity screening of novel spiro isatin substituted compounds have also been carried out. [ABSTRACT FROM AUTHOR]

In the crystal of the title vanilline derivative, 2C15H15NO4·H2O, the secondary amine molecule is accompanied by half equivalent of water. The molecule is non-planar, with torsion angle Caryl--CH2--NH--Caryl of -83.9 (2)°. In the crystal, the system of O--H...O hydrogen bonds, including bridging water molecules residing on crystallographic twofold axes, results in a two-dimensional layered structure. Within the layers, there are also weak N--H...π interactions involving the vanilline benzene ring. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tungsten-mediated transformation of alkynols in the presence of cyclic amines. • Cascade reaction for the synthesis of new diamines containing the tetrahydrofuran ring. • Proposed pathway for the formation of novel diamine. In reactions of propargylic alcohols, RH(HO)CC CH (prop-2-yn-1-ol, meso -but-3-yn-2-ol), with secondary cyclic amines (piperidine, pyrrolidine, morpholine, 1-methylpiperazine, 4-methylpiperidine and meso- 3,5-dimethylpiperidine), catalysed by cis -[W(CO) 4 (pip) 2 ], previously unknown diamines containing the tetrahydrofuran ring were isolated in relatively good yield, up to 80%, identified by GC–MS, and characterized by NMR spectroscopy. The new structures were studied by DFT: the 1H and 13C chemical shifts were calculated and compared with those observed experimentally. [ABSTRACT FROM AUTHOR]

Sulfonamides belong to an important class of compounds which show wide ranges of biological activities. Over the last few decades various pharmacological activities of sulfonamide conjugates were published. Moreover, Currently many lead compounds with sulfonamide functionality are also in clinical trial for the treatment of various medical conditions. For these reasons, development of an efficient process for the synthesis of sulfonamides has always been in the focus for research in organic synthesis. Researchers published numerous articles over the years for demonstrating effectiveness of sulfonylation and N-alkylation procedures for the synthesis of sulfonamide. The most typical method for the synthesis involves reaction between primary or secondary amines and sulfonyl chloride in presence of organic or inorganic bases. Although this method is effective, but the nucleophilicity of amines may vary depending on the groups attached to it. In general, primary amines are highly reactive, whereas secondary amines show very low to almost nil reactivity. In this study, we have reviewed recent advances related to the efficient synthetic procedures for different types of sulfonamides. [ABSTRACT FROM AUTHOR]

A class of multifunctional amidophosphanes derived from chiral 1,2-diphenylethylenediamines and natural α-amino acids has been developed. Among these, in combination with silver(I) salts, a chiral secondary amine-amidophosphane precatalyst has been demonstrated as being a highly efficient multifunctional precatalyst in the asymmetric 1,3-dipolar cycloaddition of azomethine ylides, including a series of heterocyclic, aliphatic, and 2-substituted azomethine ylides, and aromatic α,ß-unsaturated aldehyde derived imino esters with different electron-deficient alkenes, as well as the three-component reaction of α-imino esters generated in situ by using N,N'-diisopropylcarbodiimide as dehydrating agent. Under optimal conditions, highly functionalized endo-adducts were obtained in high to excellent yields (up to 99% yield) and enantioselectivities (up to >99.9% ee). [ABSTRACT FROM AUTHOR]

The continuous synthesis of bis[3-(dimethylamino)propyl]amine (BPA) by hydrogenation of 3-(dimethylamino)-propionitrile (PN) in the presence of 3-( N , N -dimethylamino)propylamine (PA) over copper-based catalysts was investigated. It was found that Cu-Cr 2 O 3 -CoO/γ-Al 2 O 3 yielded satisfactory results with almost 100% PN conversion and 88.5% BPA selectivity (H 2 pressure: 1 Mpa, temperature: 100 °C, PN/PA ratio: 2:1). All catalysts were characterized by XRD, XPS, H 2 -TPR, and TEM, the obtained results indicated that Cr could improve the catalytic activity. Moreover, Co dispersed around Cu particles promoted the catalytic nature, which could further enhance the activity and stability of the catalyst. [ABSTRACT FROM AUTHOR]

Biologically relevant halide salts and its solution state structural properties are always been significant. In general, exposure of halide salts into polar solution medium results in solvation which in turn separates the cationic and anionic part of the salt. However, the conventional behaviour of salts might alter in presence of any secondary amine based compound, i.e.; moderately strong Lewis acid. In its consequence, to investigate the effect of secondary amine based compound in the salt solution, novel (E)-2-(4-bromobenzylidene)-1-(perfluorophenyl) hydrazine has been synthesized and used as secondary amine source. The secondary amine compound interestingly shows a drastic color change upon exposure to fluoride salts owing to hydrogen bonding interaction. Several experimental methods, e.g.; SCXRD, UV–Vis, FT-IR, ESI-MS and DLS together with modern DFT ( i.e.; DFT-D3) have been performed to explore the structural properties of the halide salts upon exposure to secondary amine based compound. The effect of counter cation of the fluoride salt in binding with secondary amine source has also been investigated. [ABSTRACT FROM AUTHOR]

Donor–acceptor Stenhouse adducts (DASAs) are gaining attention from organic and material chemists due to their visible light-stimulated photochromic properties. In this report, we present a facile method for grafting coloured triene on polycarbonate surface, without involving any pre-treatments like plasma activation, etc. The chemoselectivity of carbonate with a primary amine and Meldrum's activated furan (MAF) with polymer bound secondary amine has been exploited to graft photoswitchable DASA on the polymer surface. Primary, secondary and tertiary amine-functionalized polycarbonate surfaces have been prepared to evaluate the reactivity of amine with MAF.

The synthesis of N,N‐bis(3‐dimethylaminopropyl)amine (BPA) from 3‐(dimethylamino)‐propionitrile (PN) and 3‐(N,N‐dimethylamino)propylamine (PA) over Pd/γ‐Al2O3 in autoclaves was investigated. A series of Pd catalysts were prepared by different methods and characterized by XRD, TEM, and N2 adsorption–desorption. It was found that their activities were obviously affected by calcination temperature and reducing agent. Among them, the catalyst calcined at 500 °C and reduced with NaBH4 exhibited the best performance in this reaction. It was possibly attributed to the better dispersion of palladium particles on γ‐Al2O3. Furthermore, reaction parameters were also optimized. Under optimal conditions (PN/PA molar radio 1:1, toluene as solvent), BPA was obtained in 87.9% yield with 95.6% conversion over the above catalyst. Meanwhile, split of PN was observed. A probable mechanism of retro‐Michael reaction was also proposed. [ABSTRACT FROM AUTHOR]

The synthesis of N,N‐bis(3‐dimethylaminopropyl)amine (BPA) from 3‐(dimethylamino)‐propionitrile (PN) and 3‐(N,N‐dimethylamino)propylamine (PA) over Pd/γ‐Al2O3 in autoclaves was investigated. A series of Pd catalysts were prepared by different methods and characterized by XRD, TEM, and N2 adsorption–desorption. It was found that their activities were obviously affected by calcination temperature and reducing agent. Among them, the catalyst calcined at 500 °C and reduced with NaBH4 exhibited the best performance in this reaction. It was possibly attributed to the better dispersion of palladium particles on γ‐Al2O3. Furthermore, reaction parameters were also optimized. Under optimal conditions (PN/PA molar radio 1:1, toluene as solvent), BPA was obtained in 87.9% yield with 95.6% conversion over the above catalyst. Meanwhile, split of PN was observed. A probable mechanism of retro‐Michael reaction was also proposed. [ABSTRACT FROM AUTHOR]

Four triarylamine-based high-performance polyimides with secondary amine were readily synthesized, their ionic hydrogen-bonding interaction with pyridines and anions are successfully demonstrated (20 times higher than the literature in sensitivity) by the means of electrochemistry and spectroelectrochemistry. The prepared polymer thin films having the advantage for real-time qualitative detection are great candidates as chemosensors to both pyridines and anions. [ABSTRACT FROM AUTHOR]

The solid catalysts, CaCO and MgCO, were adopted to accelerate CO absorption with diethanolamine (DEA) solvent. It turned out that these solid alkaline earth metal carbonates can accelerate CO absorption, with overall time reduction up to 14-28% for CaCO, and 11-28% for MgCO. After comparing CO loadings and time resolved amine concentrations, the solid chemicals can enhance the CO absorption of DEA and became compatible with the monoethanolamine (MEA) solution at the same CO loading without catalysts. The Lewis base can serve as heterogeneous catalysts for the amine scrubbing process and then facilitate CO absorption. These results indicated the heterogeneous catalysts can partly cover the shortage of DEA with CO absorption, and facilitate the amine scrubbing process with shorter column with ease. [ABSTRACT FROM AUTHOR]

A new one-pot and regioselective synthesis of 3,4-dihydroquinazolines by Ugi/Staudinger/aza-Wittig sequence has been developed. The Ugi-type reaction of 2-azidobenzylisocyanide, aldehyde, secondary amine and acid produced an azide intermediate, which was then treated with triphenylphosphine to give 3,4-dihydroquinazolines regioselectively in good overall yields by Staudinger/aza-Wittig reaction at room temperature. [ABSTRACT FROM AUTHOR]