Amine Salts Research Articles

Cross aldol condensation of acetaldehyde and formaldehyde in the presence of bifunctional systems

Liquid-phase cross-aldol condensation of acetaldehyde and formaldehyde in the presence of salts of various saturated and unsaturated linear amines, aromatic amines, diamines, and nitrogen bases, as well as in the presence of substituted piperazines, linear and cyclic amino acids and their derivatives, and nitrogen-containing ionic liquids, was studied. The cross-condensation products were formed in considerable amounts when amine hydrochlorides, N-benzoyl amino acids, and amino acid esters were used as catalyst. The formation of cross-condensation products is favored by increased basicity of the amino nitrogen atom in the salt and of the solvent.

Sustainable synthesis of thioimidazoles via carbohydrate-based multicomponent reactions.

The synthesis of diversely functionalized thioimidazoles through a modern variant of the Marckwald reaction is presented. This new protocol utilizes unprotected carbohydrates as well as simple amine salts as sustainable and biorenewable starting materials. Importantly it was discovered that a bifurcated reaction pathway results from using aldoses and ketoses respectively, yielding distinct reaction products in a highly selective manner.

Design and evaluation of a novel transdermal patch containing diclofenac and teriflunomide for rheumatoid arthritis therapy

The aim of this study was to design a compound transdermal patch containing diclofenac (DA) and teriflunomide (TEF) for the treatment of rheumatoid arthritis (RA). The various organic amines salts of DA were prepared and their forming was confirmed using DSC and FTIR. The percutaneous permeation of organic amines salt of DA was investigated in vitro using a two-chamber diffusion cell with excised rabbit skin as transdermal barrier. The formulation of the patch was optimized in terms of the concentration of percutaneous permeation enhancer and the loading dose of drugs. The pharmacokinetic behavior of the optimal formulation was studies in rabbits and the anti-inflammatory and analgesic effects of the optimal patch were evaluated with the adjuvant arthritis model in rats and the pain model in mice, respectively. The result showed that skin penetration of diclofenac-triethylamine (DA-TEtA) salt was better than other organic amine salts. Based on previous study of our laboratory, teriflunomide-triethylamine (TEF-TEtA) significantly enhanced the skin permeation of TEF. 10% of azone (AZ) was the best enhancer for the two drugs. The optimal patch formulation was composed of 2% of TEF-TEtA, 6% of DA-TEtA and 10% of AZ. The cumulative permeated amount of DA-TEtA in vitro was comparable with that of the commercial diclofenac-diethylamine (DA-DEtA) patch. The absolute bioavailability of TEF-TEtA was 42%, which could achieve the therapeutic drug levels. In animal study, the optimized compound patch containing DA-TEtA and TEF-TEtA displayed significant anti-inflammatory and analgesic effect, which indicated the potential of the compound patch.

Water‐Promoted Ring‐Opening Reactions of N‐Substituted Saccharins and Phthalimides by Amines

AbstractThe reactions of N‐substituted saccharins and phthalimides with amines were promoted by water. Various o‐sulfamoyl benzamides and N,N′‐disubstituted phthalamides were prepared in moderate to good yields. These reactions have prominent advantages, such as short reaction time, less by‐products and simple isolation of the products. Water can probably stabilize the reaction intermediates and facilitate precipitation of the ring‐opening products. When steric hindrance arose, hydrolytic compounds, either free acid or salts of the acids, were obtained. Possible reason for the formation of amine salts of o‐sulfamoyl benzoic acids was proposed.

Proposed chemical mechanisms leading to secondary organic aerosol in the reactions of aliphatic amines with hydroxyl and nitrate radicals

The presence and importance of amines in the atmosphere, including aliphatic amines, continues to gain more attention. The atmospheric reaction mechanisms of these amines with key atmospheric radicals are important to predict both daytime and nighttime atmospheric chemistry. While previous studies have focused on the production of amine salts, this analysis looks at the importance of peroxy radical reactions to the formation of secondary organic aerosol. Atmospheric oxidation mechanisms are presented to explain the observed chemistry. A series of environmental chamber experiments were conducted in which aliphatic tertiary and secondary amines were reacted with either hydroxyl radical (OH) or nitrate radical (NO3). Chemical composition of the aerosol products was obtained with a High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and a Particle Into Liquid Sampler Time of Flight Mass Spectrometer (PILS-ToF-MS), while the chemical composition of the gas-phase products was obtained with a Selected Ion Flow Tube Mass Spectrometer (SIFT-MS). A number of aerosol-phase mass spectra showed highly oxidized fragments at a much higher molecular weight (MW) than the amine precursor. It is proposed that these larger compounds are oligomers formed through peroxy radical reactions with hydrogen rearrangement. Another reaction pathway observed was the formation of amine salts. The relative importance of each pathway to the overall production of aerosol is found to be dependent on the type of amine and oxidant. For example, the oligomers were observed in the tertiary methyl amines, while the formation of amine salts was more prevalent in the secondary and tertiary ethyl amines.

Cloud condensation nuclei (CCN) activity of aliphatic amine secondary aerosol

Abstract. Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g., hydroxyl radical and nitrate radical). The particle can contain both secondary organic aerosol (SOA) and inorganic salts. The ratio of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN) activity. SOA formed from trimethylamine (TMA) and butylamine (BA) reactions with hydroxyl radical (OH) is composed of organic material of low hygroscopicity (single hygroscopicity parameter, κ, ≤ 0.25). Secondary aerosol formed from the tertiary aliphatic amine (TMA) with N2O5 (source of nitrate radical, NO3) contains less volatile compounds than the primary aliphatic amine (BA) aerosol. As relative humidity (RH) increases, inorganic amine salts are formed as a result of acid–base reactions. The CCN activity of the humid TMA–N2O5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR) ideal mixing rules. The humid BA + N2O5 aerosol products were found to be very sensitive to the temperature at which the measurements were made within the streamwise continuous-flow thermal gradient CCN counter; κ ranges from 0.4 to 0.7 dependent on the instrument supersaturation (ss) settings. The variance of the measured aerosol κ values indicates that simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems' κ ranges within 0.2 < κ < 0.7. This work indicates that aerosols formed via nighttime reactions with amines are likely to produce hygroscopic and volatile aerosol, whereas photochemical reactions with OH produce secondary organic aerosol of lower CCN activity. The contributions of semivolatile secondary organic and inorganic material from aliphatic amines must be considered for accurate hygroscopicity and CCN predictions from aliphatic amine systems.

Use of portable analytical methods to determine the stoichiometry of reaction for hexahydrotriazine-based hydrogen sulfide scavenger operations.

During the reaction between 1,3,5-tris(2-hydroxyethyl)hexahydro-s-triazine and hydrogen sulphide, the principle by-product is the organic sulphide 5-(2-hydroxyethyl)dithiazine. It can be determined by a novel, portable, field-capable ion mobility spectrometry method described herein and enables the "degree spent" to be determined. Dependant upon the level of carbon dioxide in the produced gas, a mixture of ethanolaminium bicarbonate and ethanolamine bisulphide is also produced. Using a field capable spectrophotometric method the level of inorganic sulphide can be determined, thus allowing the ethanolaminium bisulphide concentration to be calculated. Provided the fluid is only partially spent, and there is some unreacted 1,3,5-tris(2-hydroxyethyl)hexahydro-s-triazine remaining; the only source of inorganic sulphide is the amine salt. From a knowledge of the original fluid concentration, the combination of these two methods allows the effective stoichiometry, or observed molar reaction proportions between 1,3,5-tris(2-hydroxyethyl)hexahydro-s-triazine and hydrogen sulphide, to be measured for a specific field location.

Volatile corrosion inhibitors Part II: amine salts and amine adsorbed cation-exchangers

Amine salts and amine adsorbed cation-exchanger have been examined to ascertain their vapour phase inhibition property for protection of metals against corrosion.The investigation has shown that amine adsorbed cation-exchangers are efficient inhibitors. They can be conveniently handled unlike free amines, are less harmful to non-ferrous metals and possess a longer life. Amine nitrites and carbonates which are well known volatile corrosion inhibitors, have shown good results. Amine benzoate's and stearates have been found to provide good inhibition under milder test conditions but failed in severe exposure conditions.

Effect of ammonium salts on the properties of poly(piperazineamide) thin film composite nanofiltration membrane

Interfacial polymerization (IP) is most commonly used to fabricate thin film composite (TFC) nanofiltration (NF) membranes. The separation performance of the top thin film layer is affected by many factors such as type of monomers, surfactant, and reaction time during the IP process. This paper presents a systematic investigation on the effect of ammonium salts added in aqueous phase. Six amine salts with different molecular structures, molecular weights and size, including symmetrical and asymmetrical cationic amine group were incorporated into piperazine (PIP) solution. The formed piperazine-amide (PA) polymer layer was supported on a polyethersulfone (PES) ultrafiltation (UF) membrane. The membranes were characterized by scanning electronic microscopy (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and atomic force microscopy (AFM). The permeate and rejections of NaCl and MgSO4 were also evaluated. The NaCl rejection changed from 27.7% to 46%. It was found that ammonium salt acted as a catalyst during the IP process, transporting multi-amine monomer molecular into organic solution. It also indicated that the ammonium salt containing larger-size steric configuration cationic amine group could result in a better performance and a rougher surface. The solubility and water sorption properties of ammonium salt in organic solution are supposed to play a significant effect on membrane performance.

ChemInform Abstract: A Convenient Method to Synthesize 1,3‐Selenazolidin‐2‐ones from 2‐Chloroethyl Amine Salts by Se/CO System under Atmospheric Pressure and Temperature.

AbstractA new method for the synthesis of title compounds (III) under atmospheric pressure and at ambient temperature is presented.

Nano-indium oxide: An efficient catalyst for one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-ones with a greener prospect

Nano-In2O3 is found to be a remarkable efficient catalyst for the one-pot three-component condensation of isatoic anhydride, primary amine or ammonium salts and aromatic aldehydes for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones in aqueous media. In2O3 nanoparticles are easily recyclable without the significant loss of catalytic activities.

Isolation and Characterization of Abietic Acid

Abietic acid was isolated by means of isomerization and amination reaction-crystallization coupled with ultrasonic wave. Isomerization rosin and ethanolamine were used as raw materials, 95% ethanol as recrystallization solvent, the effects of reaction temperature, reaction time, agitating velocity, ultrasound intensity and recrystallization times on the purity and yield of abietic acid were investigated. The suitable isolation conditions were obtained as follow: reaction temperature 30 °C, reaction time 40 min, agitating velocity 400 rpm, ultrasound intensity 300 W and freeze crystallization of amine salt three times. The purity and yield of abietic acid were 98.52% and 54.93% when the suitable conditions were used. And it was then characterization by its melting point, specific rotation, UV, FTIR and NMR, all evidence indicated that the purification product was abietic acid.

Magnetic CuFe2O4 nanoparticles: a retrievable catalyst for oxidative amidation of aldehydes with amine hydrochloride salts

The application of magnetic CuFe2O4 nanoparticles for the oxidative amidation of aldehydes with amine hydrochloride salts is described. A wide range of amides have been synthesized in good to excellent yields under mild conditions. Chiral amide also synthesized from its corresponding chiral amine salt with retention of the stereochemistry. In particular, the performance of the magnetic separation of the catalyst was very efficient and an alternative to time, solvent and energy-consuming separation procedures. The catalytic activity of the catalyst remains unaltered after five consecutive cycles, making it environmentally benign and widely applicable due to its efficiency, ease of handling and cost effectiveness.

Hydrocarbon-soluble metal corrosion inhibitors. II. Physicochemical aspects of inhibitor action. Amides and salts of carboxylic acids

Some molecular aspects of protective action and specific behavior of hydrocarbon-soluble amides and salts of certain amines and morpholine with carboxylic acids in aqueousorganic environments are considered. The electron densities on those heteroatoms which are presumably responsible for adsorption and inhibition, as well as the Hansch -constants have been calculated. Hypothetical adsorption models have been suggested for tridecanoic acid amides with hexylamine, cyclohexylamine, piperidine, piperazine, morpholine and the cyclohexylamine quaternary salt. Hypothetical adsorption schemes and the probable inhibitor efficiency of the products have been analyzed with consideration for data on the electronic charges and hydrophobicity of the molecules.

The tribological behaviour and tribochemical study of B–N type borate esters in rapeseed oil—compound versus salt

Two novel borate ester additives, (2-(2-(bis(2-hydroxyethyl)amino)ethoxy)-1,3,2-dioxaborolan-4-yl)methyl oleate and a tris(2-hydroxyethyl)amine salt of (2-hydroxy-1,3,2-dioxaborolan-4-yl)methyl oleate were prepared and used as anti-wear and extreme pressure agents in rapeseed oil. The tribological performance was evaluated using a four-ball machine. The results show that the additives possess high anti-wear and extreme pressure properties. XANES, XPS and AFM were used to analyse the composition and structure of boundary films at the worn surfaces. The results for the compound and salt of borate esters are compared, and it is shown that the boundary films formed by compound or salt are similar and mainly composed of B2O3.

Effects of amine, amine salt and amide on the behaviour of carbon dioxide absorption into calcium hydroxide suspension to precipitate calcium carbonate

The amount of carbon dioxide (CO2) absorption and calcium ion (Ca2+) concentration besides the pH of aqueous solution were observed during the CO2 absorption to precipitate calcium carbonate (CaCO3) from calcium hydroxide (Ca(OH)2). A reaction rate-limiting effect of an amount of CO2 absorption without any organic additives in the early stage of the precipitation was observed, which was attributed to an interruption effect of bicarbonate ion (HCO−3) on the precipitation of CaCO3. The improvement for the reaction rate was achieved not only by amine additives but also by neutral additives such as ε-caprolactam or amine salt. When the hexamethylene diamine was dissolved in the solution, successive change of crystal forms of CaCO3 aragonite to calcite in aqueous suspensions, confirmed by Ca2+ concentration change and X-ray diffraction, was concluded that a local environment around the amine group in aqueous solution and an interaction of the diamine with precipitated CaCO3 particles were important factors for these reactions.

Masked Thiol Sugars: Chemical Behavior and Synthetic Applications of S‐Glycopyranosyl‐N‐monoalkyl Dithiocarbamates

The chemical behavior of S-glycopyranosyl-N-monoalkyl dithiocarbamates (DTCs) as masked 1-glycosyl thiols, easily prepared by the nucleophilic displacement of 1-halo sugars with dithiocarbamate salts of primary amines, has been studied and synthetically exploited. This behavior relies on the abstraction of the proton of the carbamate functionality that allows controlled access to thiolate sugar intermediates. The basic character of the DTC salts used as reagents leads to thiolates that evolve in situ to symmetrical diglycosyldisulfides (DGDSs) when long reaction times are allowed. Alternatively, controlled unmasking of the thiolate function can be efficiently attained by treatment with an external base of isolated anomeric glycosyl DTCs, the formation of which is prevalent when using short reaction times. In this manner, a second methodology for the preparation of symmetrical DGDSs and a chemical protocol for the S-glycosylation of any electrophilic substrate are established. The applications of this last strategy for the preparation of thioglycosyl vinyl sulfones, thiodisaccharides, and S-linked homo- and heterodivalent neoglycoconjugates are described as a proof-of-concept of the great potential of the sugar DTCs in any chemical scenario in which the covalent attachment of a thiol sugar is required. The evaluation of the biological functionality of some divalent sulfurated sugar systems is also described.

A Convenient Method to Synthesize 1,3‐Selenazolidin‐2‐ones from 2‐Chloroethyl Amine Salts by Se/CO System under Atmospheric Pressure and Temperature

ABSTRACT1,3‐Selenazolidin‐2‐ones were successfully synthesized by the reaction of 2‐chloroethyl amine salts with the Se/CO system via selenation and carbonylation in the presence of NaOH under atmospheric pressure and temperature, and were characterized by gas chromatography–mass spectrometry and nuclear magnetic resonance.

Functional status of neutrophils at 2,4-dichlorophenoxyacetic acid amine salt intoxication

Aim. To study the influence of 2,4-dichlorophenoxyacetic acid amine salt subacute intoxication on the functional status of neutrophils. Methods. 2,4-dichlorophenoxyacetic acid amine salt (42 mg/kg) was administered intragastrically during 28 days. The number of leukocytes, neutrophils and lymphocytes in peripheral blood, intensity of oxygen-dependent metabolism (spontaneous and induced tetrazolium test), absorbency, microbicidal activity of neutrophils in conditions of oxygen-dependent microbicidal factors functioning and sodium azide mediated blockade, the level of myeloperoxidase and cation proteins in neutrophils were registered at days 7th and 14th after the toxicant administration discontinuation. Results. Subacute 2,4-dichlorophenoxyacetic acid amine salt intoxication resulted in leucopenia due to neutropenia, accompanied by inhibition of oxygen-dependent neutrophils killing as the result of peroxidase-independent microbicidal mechanisms suppression (reduced synthesis of oxygen active forms). A reduced activity of oxygen-independent killing mechanisms correlating with a decrease of cation proteins levels was also registered. On the 14 day, leucopenia was replaced by leukocytosis due to elevated numbers of neutrophils and lymphocytes in the peripheral blood. At the same time, the activity of both oxidative peroxidase-dependent and oxygen-independent microbicidal mechanisms in neutrophils continued to decrease, accompanied by reduction of mieloperoxidase activity, neutrophil absorbency and cation proteins levels. Conclusion. Subacute intoxication with 2,4-dichlorophenoxyacetic acid amine salt leaded to quantitative and functional disorders in neutrophils that persisted by the 14 day of follow-up, indicating a need for further study of of 2,4-dichlorophenoxyacetic acid amine salt immunotoxic action to find the possible opportunities for its pharmacological correction.

Efficiency of tactivin and tocopherol for 2,4-dichlorophenoxyacetic acid amine salt hepatotoxicity correction

Aim. To study the efficiency of individual and combined use of thymus extract (tactivin) and vitamine E (tocopherol) for 2,4-dichlorophenoxyacetic acid amine salt hepatotoxicity correction. Methods. Experiments were carried out on 75 white non-imbred mature rats. Animals were distributed to 5 groups 15 animals each: controls, receiving 2,4-dichlorophenoxyacetic acid amine salt, receiving 2,4-dichlorophenoxyacetic acid amine salt and tactivin, receiving 2,4-dichlorophenoxyacetic acid amine salt and tocopherol, receiving 2,4-dichlorophenoxyacetic acid amine salt and both tactivin and tocopherol. 2,4-Dichlorophenoxyacetic acid amine salt (42 mg/kg) was introduced into the stomach during 28 days. Tocopherol (50 mg/ kg) and Tactivin (0,25 mg/kg) were injected from day 1 to day 6 after the discontinuation of toxin administration. Serum levels of alanine aminotransferase, aspartate transaminase, total and direct bilirubin were examined. The liver morphological state was assessed by microscopy of the liver tissue slices stained with hematoxylin and eosin, electron microscopy was also performed.The results were registered on the 7th day after the toxin discontinuation. Results. 2,4-Dichlorophenoxyacetic acid amine salt led to alanine aminotransferase, aspartate transaminase, total and direct bilirubin levels increase. Hemodynamic alterations, reduced number of mitoses, increased number of necrotic hepatocytes, fiber tissue scarring were observed morphologically. The use of tactivin reduced the severity of morphological changes, and decreased, but did not normalized the level of transaminases and bilirubin. The use of tocopherol normalized the level of transaminases, bilirubin, there were morphological signs of the regeneration processes and hepatocyte mitotic activity intensification. The combined use of tactivin and tocopherol normalized alanine aminotransferase, aspartate transaminase bilirubin levels. Morphologically, signs of regenerative processes and protein synthesis activation were observed in hepatocytes. Conclusion. Tocopherol and Tactivin effectively compensate the hepatotoxic effect of 2,4-dichlorophenoxyacetic acid amine salt, the best result was obtained when both of the drugs used in combination.