Dimethylethanolamine Research Articles

A new catalytic transesterification for the synthesis of N, N-dimethylaminoethyl acrylate with organotin catalyst

A new transesterification method for preparing N, N-dimethylaminoethyl acrylate (DMAEA) from methyl acrylate (MA) and dimethylaminoethanol (DMAE) was carried out in the presence of organotin catalyst. Among the catalysts examined, (C8H17)2Sn(OCOC11H23)2(TD) is the most active one for the reaction. The products were characterized by gas chromatography, IR spectroscopy, NMR spectroscopy and Mass spectroscopy. The effects of various reaction conditions such as the different catalysts, the reactants ratio, the amount of catalyst, the reaction time on the DMAE conversion, the selectivity to DMAEA and the DMAEA yield were investigated. Experimental results indicated that the sort of catalyst is vital to improving DMAEA yield. The reactants ratio could effect on the DMAE conversion, the selectivity to DMAEA and the DMAEA yield. The 96.28% conversion of DMAE was obtained over catalyst TD, the yield of DMAEA could reach 94.65%, the selectivity is 98.68%. A possible catalytic mechanism of transesterification of DMAE and MA with organotin catalysts was also presumed.

A water-soluble polyimide precursor: Synthesis and characterization of poly(amic acid) salt

We have synthesized a water-soluble polyimide precursor, poly(amic acid) amine salt (PAD), from pyromellitic dianhydride (PMDA), 4,4′-oxydianiline, andN,N′-dimethylethanolamine (DMEA) and have investigated in detail its properties with respect to the degree of salt formation (D sf ). The maximum value ofD sf we obtained upon precipitation of the precursor solution into acetone was 79%. We synthesized a PAD having aD sf of 100% (PAD100) by the solid state drying of an organic solution. The precursors showed different solubility depending on theD sf to make up to 4 wt% solutions in water containing a small amount of DMEA. PAD100 is completely soluble in pure water. We investigated the imidization behavior of PAD in aqueous solution using various spectroscopic methods, which revealed that PAD100 has faster imidization kinetics relative to that of the poly(amic acid)-type precursors. The resulting polyimide films prepared from an aqueous precursor solution possess almost similar physical and thermal properties as those prepared from N-methyl-2-pyrrolidone(NMP) solution. Therefore, we have demonstrated that PAD can be used as a water-based precursor of polyimide; this procedure avoids the use of toxic organic solvents, such as NMP.

Highly efficient automated synthesis of [ 11C]choline for multi dose utilization

[ 11C]Choline has been under investigation as a PET ligand for imaging tumor tissue, especially prostate cancer. An improved, automated synthesis of the tracer now was established. [ 11C] Choline was produced by labeling 2-(dimethylamino)-ethanol (DMAE) with [ 11C]CH 3I in a Tefzel ® tube at room temperature without solvent. The product was purified using a cation exchange cartridge. Reaction conditions were optimized with respect to synthesis time and amount of DMAE, resulting in radiochemical yields higher than 80% using 60 μl of DMAE in 20 min, radiochemical purity was >99% and residual DMAE was below 10 ppm. After 11C-production of 1 h at 50 μA [ 11C]choline activities of 30.0±5.6 GBq ( n=29) were obtained in sterile solution ready for intravenous administration.

DMAE contributes to mildness of a facial cleanser designed for sensitive skin

Consumers with hyperirritable skin often sacrifice product aesthetics in order to appease their reactive skin. During the development of a facial cleanser for sensitive skin that provides a luxurious cleansing experience, several prototypes were screened for mildness. Evaluations included skin grading, digital photography and instrumental measurements to establish a winning formula, followed by aesthetics optimization. The cleanser’s mildness was then confirmed in a double-blind clinical study on subjects with mild to moderate rosacea. A dermatologist-recommended, gentle skin cleanser was used as the benchmark for comparison. The anti-inflammatory function of DMAE (dimethylaminoethanol) was evident during prototype screening.

The sea urchin embryo as a model for mammalian developmental neurotoxicity: ontogenesis of the high-affinity choline transporter and its role in cholinergic trophic activity.

Embryonic development in the sea urchin requires trophic actions of the same neurotransmitters that participate in mammalian brain assembly. We evaluated the development of the high-affinity choline transporter, which controls acetylcholine synthesis. A variety of developmental neurotoxicants affect this transporter in mammalian brain. [3H]Hemicholinium-3 binding to the transporter was found in the cell membrane fraction at stages from the unfertilized egg to pluteus, with a binding affinity comparable with that seen in mammalian brain. Over the course of development, the concentration of transporter sites rose more than 3-fold, achieving concentrations comparable with those of cholinergically enriched mammalian brain regions. Dimethylaminoethanol (DMAE), a competitive inhibitor of choline transport, elicited dysmorphology beginning at the mid-blastula stage, with anomalies beginning progressively later as the concentration of DMAE was lowered. Pretreatment, cotreatment, or delayed treatment with acetylcholine or choline prevented the adverse effects of DMAE. Because acetylcholine was protective at a lower threshold, the DMAE-induced defects were most likely mediated by its effects on acetylcholine synthesis. Transient removal of the hyaline layer enabled a charged transport inhibitor, hemicholinium-3, to penetrate sufficiently to elicit similar anomalies, which were again prevented by acetylcholine or choline. These results indicate that the developing sea urchin possesses a high-affinity choline transporter analogous to that found in the mammalian brain, and, as in mammals, the functioning of this transporter plays a key role in the developmental, trophic activity of acetylcholine. The sea urchin model may thus be useful in high-throughput screening of suspected developmental neurotoxicants.

Crystallization of Organic Compounds in Reversed Micelles. III. Solubilization of Aspartame

The artificial sweetener, aspartame, is a dipeptide, consisting of a hydrophobic phenylalanine methyl ester entity and a hydrophilic aspartyl residue. In this work, its solubilization in five different types of water in oil (w/o) microemulsions (MEs) was investigated. The stabilizing surfactants and cosurfactants of the MEs were ME 1, sodium di-2-ethylhexyl sulfosuccinate (AOT) and no cosurfactant; ME 2, maleic anhydride α-olefin copolymer and dimethyl amino ethanol; ME 3, sucrose ester monostearate and n-butanol; ME 4, l-α-phosphatidylcholine and n-butanol; and ME 5, mono- and diglycerides of fatty acids and l-α-phosphatidylcholine. The maximum amount that could be dissolved (boundary concentration) was determined by adding powdered aspartame to a heated ME and cooling to a specified temperature under controlled conditions. The solutions that remained clear for at least 4 days were regarded as stable, and those of the stable solutions with the highest aspartame concentrations were taken as having the boundary concentrations. From the solubility data, the distribution of the aspartame molecules between the w/o interface and the water pools was calculated, and the results were correlated with the molecular structure and ionic state of the surfactant. The results show that aspartame can be solubilized in all the investigated MEs to an extent, exceeding by far its solubility in pure water, and that overall solubilization is most efficient in water/isooctane MEs stabilized with AOT (ME 1). While the aspartame solubility in the water pools was comparable in all the investigated MEs, the aspartame/surfactant molar ratio at the w/o interface was found to decrease with decreasing polarity of the stabilizing surfactant at the interface. In addition to the solubilization studies, the effect of aspartame on some properties of ME 1 was investigated. It was found that aspartame lowers the interfacial tension at the water/isooctane/AOT interface and, under certain conditions, stabilizes unstable mixtures of water, isooctane, and AOT. The results of small-angle X-ray scattering measurements show that the ME droplet sizes increase in the presence of aspartame molecules and their shapes change from near spherical to ellipsoidal. It was concluded that aspartame acts as a cosurfactant in water/isooctane MEs stabilized with AOT.

Studies on the performance of migratory corrosion inhibitors in protection of rebar concrete in Gulf seawater environment

In recent years, migratory corrosion inhibitors (MCI) have been suggested as the possible chemicals for rehabilitating the damaged reinforced concrete structure. The inhibitor migrates through the concrete to the reinforcing steel and protects it from further corrosion by providing a thin, protective coating of MCI-molecules on steel reinforcement. Studies have been carried out to investigate the performance of dimethyl ethanol amine based MCI-A and triethanol amine based MCI-B as surface coatings. Reinforced concrete specimens coated with MCI-A and MCI-B were subjected to exposure tests in salt solutions. The tests were consisted of immersing the specimens in 5% NaCl solutions (laboratory tests) and open seawater or exposing the specimens to high tide (splash zone) for periods ranging from 6 to 12 months. The condition of the exposed specimens was evaluated by physical examination of the rebar and also by carrying out electrochemical measurements. The electrochemical studies were consisted of open circuit potential and polarization measurements. The experimental data from the studies have been analyzed and the usefulness of MCI in protecting the rebar concrete is discussed.

Visual and ocular changes associated with exposure to two tertiary amines

Aims: To determine if exposure to dimethylisopropanolamine (DMIPA) and dimethylaminoethanol (DMAE) in a label printing plant was associated with visual disturbances and/or ocular changes. Methods: Questionnaires, eye examinations (visual acuity,...

Complete corrosion inhibition of lamellar zinc pigment in aqueous alkaline media

Lamellar zinc pigment reacts in aqueous alkaline media (e.g., water-borne paints) with the evolution of hydrogen. This corrosion reaction can be inhibited by 2-nitrophenol (2-NP), 2,4-dinitrophenol (2,4-DNP), 2-hydroxy-3,5-dinitro-benzoic acid (HDNBA) and 2-hydroxy-3-nitro-benzoic acid (2-H-3-NBA) which all have a nitro-group ortho to a hydroxy-group; this structural part of the inhibitors can be considered as a potential chelating group which may explain the corrosion inhibiting effect. As a rule, with triethylamine (TEA) as neutralizing agent corrosion inhibition is slightly better when compared to dimethylethanolamine (DMEA). With TEA there is complete corrosion inhibition with addition of 2,4-DNP at pH 8 and 10; with 2-H-3-NBA there is complete inhibition at pH 10.

New homo- and hetero-alkali metal alkoxide cages; crystal structures of [Me2N(CH2)2OLi]8 and [{Me2N(CH2)2O}12Li8K6

The reaction of N,N′-dimethylaminoethanol (DMAEH), (Me)2N(CH2)2OH, with nBuLi and nBuLi/nBuK respectively results in the formation of the homo- and hetero-metallic alkoxides [Me2N(CH2)2OLi]8, 1, and [{Me2N(CH2)2O}12Li8K6]O, 2, rather than mixed alkyl–alkoxide species. From single crystal X-ray diffraction studies the two complexes are shown to be highly aggregated cage structures. Complex 1 (monoclinic, C2/c) adopts a rare octameric structure constructed from a ring stacked hexamer fused with a (LiO)2 dimer creating a sixteen vertex Li–O cluster. Complex 2, which crystallises (rhombohedral, R) with thf and cyclohexane molecules in the lattice, forms a highly symmetrical, almost spherical, cage with an unprecedented Li ∶ K ratio of 8 ∶ 6.

Thermodynamic transfer functions at infinite dilution and clathrate formation of ethanolamines in water

The ultrasonic velocities and densities of solutions of water in various binary aqueous solutions of ethanolamines were measured over the full range of compositions at 298, 308 and 318 K. The experimental data in the dilute region with mole fraction of water <0.1 was analyzed to determine the partial molar volume and adiabatic compressibilities at infinite dilution. Compressibility isotherms intersect approximately at a common point for triethanolamine (TEA), methyldiethanolamine (MDEA), dimethylethanolamine (DMEA) and diethylethanolamine (DEEA) and this is attributed to the formation of quasi-clathrate-like structures in the liquid solutions. The standard thermodynamic transfer functions were calculated to evaluate the environment of water at infinite dilution in these systems. The transfer functions of water between the various ethanolamines are considerably larger for ethanolamines that differ in their degree of hydrophobicity.

Thermodynamic properties of aqueous diethanolamine (DEA),N,N-dimethylethanolamine (DMEA), and their chloride salts: apparent molar heat capacities and volumes at temperatures from 283.15 to 328.15 K

Apparent molar heat capacities Cp,ϕand apparent molar volumes Vϕfor aqueous diethanolamine (HOC2H4)2NH, diethanolammonium chloride (HOC2H4)2NH2Cl, N,N'-dimethylethanolamine (HOC2H4)(CH3)2N, and N,N'-dimethylethanolammonium chloride (HOC2H4)(CH3)2NHCl were determined from 283.15 to 328.15 K with a Picker flow microcalorimeter and vibrating tube densimeter. The experimental results have been analyzed in terms of Young's Rule with the Guggenheim form of the extended Debye-Hückel equation and appropriate corrections for chemical relaxation effects. These calculations lead to standard partial molar heat capacities and volumes for the neutral amines, (HOC2H4)2NH(aq) and (HOC2H4)(CH3)2N(aq), and the ions (HOC2H4)2NH2+(aq) and (HOC2H4)(CH3)2NH+(aq) over the experimental temperature range. Key words: standard partial molar volumes, standard partial molar heat capacities, diethanolamine, dimethyethanolamine, aqueous alkanolamine ionization.

Thermodynamic properties of aqueous diethanolamine (DEA), &lt;i&gt;N&lt;/i&gt;,&lt;i&gt;N&lt;/i&gt;-dimethylethanolamine (DMEA), and their chloride salts: apparent molar heat capacities and volumes at temperatures from 283.15 to 328.15 K

Thermodynamic properties of aqueous diethanolamine (DEA), &lt;i&gt;N&lt;/i&gt;,&lt;i&gt;N&lt;/i&gt;-dimethylethanolamine (DMEA), and their chloride salts: apparent molar heat capacities and volumes at temperatures from 283.15 to 328.15 K

Synthesis and characterization of novel phthalocyanines with four tridentate NNS substituents and four chloro groups

Two new 4,5-disubstituted phthalonitrile derivatives have been prepared from tridentate amine thiol reactants obtained by reducing directly two different benzothiazolines. Novel metal free phthalocyanines and divalent metal phthalocyanines carrying four tridentate NNS substituents in addition to four chloro groups on peripheral positions have been synthesized from the corresponding phthalonitrile derivatives in the presence of a suitable anhydrous metal salt [Zn(CH3CO2)2 or NiCl2] or 2-(dimethylamino)ethanol. A lutetium(III) bis(phthalocyaninate) complex that is highly soluble in most organic solvents has been synthesized from reaction of one of the phthalonitrile derivatives with anhydrous lutetium(III) acetate in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (dbu) in 1-hexanol. The newly synthesized compounds have been characterized by elemental analyses, IR, 1H, 13C NMR, MS, UV/VIS, ESR, and atomic absorption spectroscopy. Cyclic voltammetric measurements of the novel compounds have been made.

Interactions of N,N′-dimethylaminoethanol with steel surfaces in alkaline and chlorine containing solutions

Formulations based on dilute aqueous solutions of N,N′-dimethylethanolamine (DMEA) are used to protect reinforcement steel bars (‘rebar’) in concrete from corrosion. In a previous paper we discussed the usefulness of X-ray photoelectron spectroscopy (XPS) to detect DMEA adsorbed from solution and the application of secondary neutral mass spectrometry (SNMS) to study migration of DMEA through a cement matrix. In this report we present XPS data of DMEA adsorbed on steel surfaces from alkaline and chlorine containing solutions of variable concentration range and discuss models for the interaction of DMEA with the oxidized steel surface and the mechanism of corrosion inhibition of DMEA. DMEA is strongly bonded to the steel surface and displaces ionic species from the substrate/solution interface hence protecting the ironoxide surface from ionic attack.

ＦＡＢ‐ＭＳと酸分解法を用いる蛋白質・ペプチドのカルボキシ末端配列分析法

We have developed the following unique methods essentially for carboxyl (C)-terminal sequencing of proteins and peptides.The first and important observation was the successive truncation reaction of peptide with the use of 90% pentafluoropropionic acid (PFPA) and heptafluorobutyric acid (HFBA) at 90°C for 4-24 h by FAB and ESI-MS. This observation indicated two informations, one of which was the reaction-intermediate to be the prediction of the oxazolones at respective carboxyl termini of the truncated fragments, and the other was internal bond specific cleavages of carboxyl side of aspartic acid residue (Asp-C) and amino side of serine residue (Ser-N) as the side reactions.The prediction of oxazolone promoted to use perfluorate anhydride. The extensive successive truncation was also carried out even at -20°C within 1 h by the use of the perfluorate anhydride in acetonitrile solution.The side reactions, Asp-C and Ser-N were further studied; 0.2% PFPA aqueous vapor at 60°C for 24 h selectively cleaved Asp-Pro bond (60°C, h) and the same acid vapor at 90°C for 4-8 h cleaved Asp-C. An aqueous 90% PFPA vapor at 25°C for 48 h made N-O peptidyl shift at Ser/Thr. This was reacted with a vapor of 20% acetic anhydride and 1% acetic acid in acetoritrile at 60°C for 1 h. The reaction acetylated the free NH2-group of the Ser/Thr and the shifted peptide fragments. And finally 20% dimethylaminoethanol (DMAE) aqueous solution at 60°C for 30 min cleaved the O-ester peptide fragment off from OH-group of Ser/Thr residue.These two specific cleavages can be used for protein-identification by the aid of “peptide mass databases” made from protein sequence database.The successive truncation accompanied by Asp-C or Ser-N cleavages with 90% PFPA at 90°C for 1, 2, 4, and 8 h yielded multi-C-terminal sequences of protein. The data of several residues at several sites in protein provided information for protein identification again as well as for general gene technology. In the last two methodologies TOF-MS and FAB-MS were efficiently employed.A step wise C-terminal sequence method has been developed from the successive truncation reactions, which composed of the following three reactions; (1) formation of oxazolone and acetylation of the N-terminus with a vapor of acetic anhydride with 10% acetic acid at 60°C for 1 h; (2) cleavage off the C-terminal amino acid from the oxazolone and esterification of the peptide, and liberation of the C-terminal amino acid, with a vapor of 5% PFPA in methanol (ethanol) solution at 5°C for 5 min; and 3) hydrolysis of the peptide ester with 20% DMAE aqueous solution at 60°C for 10 min. And the products is ready to the next step reaction.

Molar heat capacities of alkanolamines from 299.1 to 397.8 K Group additivity and molecular connectivity analyses

Y. Maham, L. G. Hepler, A. E. Mather, A. W. Hakin and R. A. Marriott, J. Chem. Soc., Faraday Trans., 1997, 93, 1747 DOI: 10.1039/A607568A

Characterization of soybean choline kinase cDNAs and their expression in yeast and Escherichia coli.

An expressed sequence tag from Arabidopsis that displayed sequence homology to mammalian and yeast choline kinases was used to isolate choline kinase-like cDNAs from soybean (Glycine max L.). Two distinct cDNAs, designated GmCK1 and GmCK2, were recovered that possessed full-length reading frames, each sharing approximately 32% identity at the predicted amino acid level with the rat choline kinase. A third unique choline kinase-like cDNA, GmCK3, was also identified but was not full length. Heterologous expression of GmCK1 in yeast (Saccharomyces cerevisiae) and GmCK2 in both yeast and Escherichia coli demonstrated that each encodes choline kinase activity. In addition to choline, other potential substrates for the choline kinase enzyme include ethanolamine, monomethylethanolamine (MME), and dimethylethanolamine (DME). Both soybean choline kinase isoforms demonstrated negligible ethanolamine kinase activity. Competitive inhibition assays, however, revealed very distinct differences in their responses to DME and MME. DME effectively inhibited only the GmCK2-encoded choline kinase activity. Although MME failed to effectively inhibit either reaction, an unexpected enhancement of choline kinase activity was observed specifically with the GmCK1-encoded enzyme. These results show that choline kinase is encoded by a small, multigene family in soybean comprising two or more distinct isoforms that exhibit both similarities and differences with regard to substrate specificity.

Synthesis of 2-(dimethylamino)ethanol by the hydrogenolysis of tris(2-hydroxyethyl)amine

A new reaction for the selective hydrogenolysis of tris(2-hydroxyethyl)amine into 2-(dimethylamino)ethanol by molecular hydrogen over metallic palladium catalyst is disclosed.

Benzyldimethylamine(BDMA) and dimethylaminoethanol as the catalysts of choice for epoxy resin embedding media

INTRODUCTION: By long held tradition, many epoxy resin embedding media are catalyzed with 2,4,6-Tri(dimethylaminomethyl)phenol (DMP-30). Embedding media polymerized in this manner are widely-used and produce acceptable results, nevertheless they show high viscosity, a rapid loss in fluidity, and ultimately a shortened useful pot-life necessary for complete specimen infiltration. Perhaps using less viscous catalysts, such as Benzyldimethylamine (BDMA) or Dimethylaminoethanol (DMAE), would yield embedding media with lowered viscosity and prolonged fluidity, both very important characteristics that would ensure complete infiltration and strengthening of tissues subsequent to microtomy and ultrastructural study.MATERIALS &amp; METHODS: The amine catalysts BDMA, DMAE, and DMP-30 were tested for Average Flow Time (AFT) and Volume Flow Rate (VFR) by recording the time necessary for 9 ml of each component to flow from a vertically oriented viscosimeter. Viscosity (cp), which is a relative measure of fluidity and a real correlate of AFT/VFR, then was calculated with the Hagen-Poiseville relation for laminar flow as applied to fluids. Embed 812 and LX112 media were prepared and catalyzed either with BDMA, DMAE, or DMP-30 and their AFT, VFR, and cp similarly determined @ 5, 30, and 60 minute intervals after initial mixing.