Methylamine buffer

Cyanoamidines such as (10) are converted into the more useful 2-formyl-A-norsteroids (11) by reduction with lithium in methylamine (buffered with ammonium acetate) followed by hydrolysis on hydrated alumina. This yields a mixture containing approximately 5 parts of the 2j5-aldehyde and 3 parts of the 2a-aldehyde (11). Both aldehydes are smoothly dehydrogenated by 2,3-dichloro-5,6-dicyanobenzoquinone in the presence of acid to the 2-formyl--A-iiorsteroids (12). ... 

You are planning to carry out a reaction that produces protons. The reaction will be buffered at pH = 10.5. Would it be better to use a protonated methylamine/methylamine buffer or a protonated ethylamine/ethylamine buffer (pJ a of protonated methylamine = 10.7 p f, of protonated ethylamine = 11.0)... 

Khan, M.N., Ohayagha, J.E. Kinetic studies on the cleavage of phthahmide in methylamine buffers. React. Kinet. Catal. Lett. 1996, 58(1), 97-103. 

The Values of Observed Absorbance (Ao, ) at 300 nm as a Function of Reaction Time (t) of a Reaction Mixture Containing Phthalimide (PTH) and 0.08-M Methylamine Buffer of pH 10.93... 

Schopf and Lehmann found that lobelanine could be synthesised by keeping at 25° a mixture of glutardialdehyde, methylamine hydrochloride and benzoylacetic acid in a buffered solution. The best yield was obtained at pH 4-5, and appeared to be complete in forty hours. At pH 7 or 9, 11 or 13, the yield was very small. This synthesis under physiological conditions is represented as occurring in accordance with the following scheme —... 

Methylamine (CH3NH2) is a gas at room temperature and very soluble in water. An aqueous solution of methylamine has Kb = 4.2 X 10-4. How many liters of methylamine at 27°C and a pressure of 1.2 atm should be bubbled into 0.750 Lofa solution that is 0.588 M in the methylammonium ion (CH3NH3+) so that a buffer of pH 9.80 is obtained Assume no volume changes after methylamine is bubbled into the solution and ignore the vapor pressure of water. 

Briefly, liposomes (10mM) were incubated for 30minutes at 37°C for egg phosphatidylcholine (EPC) and at 60°C for HSPC-based liposomes with 50 X 10 dpm of methylamine (1 x 10 dpm/mole). At the end of incubation an aliquot of this mixture was passed down a Sephadex G-50 minispin column equilibrated in 10 mM histidine-sucrose buffer 10%, pH 6.7 buffer. Liposomes were eluted at the column void volume and separated from the unencapsulated methylamine. The concentration of liposomes in the original liposomal dispersion and in the void volume fraction was determined from the organic phosphorus (phospholipid) concentration (see section Lipid Quantification and Chemical Stability above) (10,49,53). 

Some commonly used buffers, such as sodium and potassium phosphate, are incompatible with ELSD, but there are ready alternatives. For example, ammonium acetate has similar buffering properties to potassium phosphate, and ammonium carbonate, ammonium formate, pyridinium acetate, and pyridinium formate are options for different pH ranges. Typical mobile phase modifiers that do not meet the volatility criteria can be replaced by a wide variety of more volatile alternates. For example, phosphoric acid, commonly used as an acid modifier fo control pH and ionization, can be replaced by trifluoroacetic acid other acids that are sufficiently volatile for use with FLSD include, acetic, carbonic, and formic acids. Triethylamine, commonly used as a base modifier, is compatible with FLSD other base modifiers that can be used are ethylamine, methylamine, and ammonium hydroxide [78]. 

Condensation reactions of aniline and of other bases with aromatic aldehydes to give Schiff s bases are accelerated by ultraviolet light in buffered media. For example, o-phenylenediamine reacts with formic acid to yield benzimidazole and acetylacetone reacts with guanidine to form 2-amino-4,6-dimethylpyrimidine.162 Similarly, lobelanine is formed by the photocondensation of glutaraldehyde, benzoylacetic acid, and methylamine hydrochloride.163... 

It has been shown that 3 is biotransformed in a reaction catalysed by monoamine oxidase B to species that cause the selective degeneration of nigrostriatal neurons, giving rise to a Parkinsonian syndrome in man and other primates. Studies of this process have shown that the pyridinium salts 4 and 5 are involved, and that 4 undergoes spontaneous disproportionation to 5 and 3 5 is the putative ultimate neurotoxin. More recent studies have shown that 4 undergoes a spontaneous reaction in pH 7.4 buffer to give methylamine and a product identified as 6. 

The weakest acid has the highest pK it is protonated methylamine (CH3NH3+). Phosphates are intracellular, whereas bicarbonate and H2C03 are extracellular buffers. 

Resuspend the dried protein in 50 yuL of fresh 8 M urea-80 mM methylamine-0.5 M ammonium bicarbonate. Avoid heating this buffer during preparation. Heat increases the formation of cyanate in the urea that can lead to the carbamylation of the e-amino group of lysine residues. Meth-ylamine helps eliminate cyanate in urea. 

Hydroxyapatite. This can be obtained from many sources (hydrox-ylapatite, BDH Chemicals Ltd., Poole, Dorset, U. K. BioGel HT, Bio-Rad Laboratories, Richmond, California), or it can be prepared in the laboratory. Our experience is limited to hydroxylapatite from BDH Chemicals, which is supplied in 50 mM phosphate buffer, pH 7.0. Before use, it was resuspended in 5 mM phosphate buffer, pH 7.0, or in Trisfhy-droxymethyl)methylamine-hydrochloric acid (Tris-HCl) buffer, pH 7.5, at a concentration of approximately 1 g/ml. It can also be used as an acetone-dried powder in a similar fashion to that described for Florisil. ... 

Robinson s classical synthesis of tropinone was achieved by condensation of succindialdehyde and methylamine with acetonedicarboxylic acid. Schbpf later carried out the reaction in a solution buffered to pH 5 and at room temperature and... 

Suppose that you have a solution that is 0.50 M in methylamine, CH3NH2, and 0.00050 M in the salt methyl-ammonium chloride, CH3NH3CI. Would you expect this to be an effective buffer solution Why or why not ... 

The conditions which favor the production of high yields of fine quality products are as follows. There should be a small amount of formic acid in the reaction mixture, because it acts as a catalyst. It should be buffered by the presence of some free methylamine, to prevent the pH of the reaction mixture from falling too low (becoming too acidic). The presence of water in the reaction mixture is to be avoided at all costs, because this really messes up the reaction. It prevents the phenylacetone from dissolving in the N-methylformamide, leading to low yields of... 

The second synthesis of pseudopelletierine involves throughout only conditions approximating those which could exist in the plant. An aqueous, buffered solution of glutardialdehyde, methylamine hydrochloride and acetonedicarboxylic acid is kept at 25° for 8 days. The ether extract of this solution gives a 72% yield of pseudopelletierine which crystallizes readily. Good yields of the alkaloid are obtained at pH 3-13 but the best yields are produced at pH 5-7 (244). 

The synthesis of lobelanine has also been achieved by an elegant method which affords a beautiful example of a synthesis carried out under so-called physiological conditions (491). A mixture of glutaric dialdehyde, methylamine hydrochloride and benzoylacetic acid kept in a buffered solution at pH 4 and 25° for 8 hours gives a 90% yield of lobelanine thus ... 

CAS 77-86-1 25149-07-9 108195-86-4 EINECS/ELINCS 201-064-4 Synonyms 2-Amino-2-(hydroxymethyl)-1,3-propanediol Aminotrimethylol-methane Aminotris(hydroxymethyl) methane THAM Tris Trisamine Tris Buffer Tris (hydroxymethyl) methanamine Tris (hydroxymethyl) methylamine 1,1,1-Tris (hydroxymethyl) methylamine Trometamol ... 

Uses Solubilizer solvent for many org. and inorg. compds., plastic films dye solvent, dye assistant for textiles mfg. of methylamine denaturing alcohol In organic synthesis drug intermediate in mfg. of ampicillin, cephaclor, etc. solder flux ingred. plasticizer in leather, cloth films, coatings stabilizer humectant in paper accelerator buffer in lacquers, explosives, cosmetics prep, of hypnotics photochemicals biocides cryoscopy vehicle in pharmaceuticals antidote... 

Trisamine Tris Buffer Tris (hydroxymethyl) methanamine Tris (hydroxymethyl) methylamine 1,1,1-Tris (hydroxymethyl) methylamine... 

On-capillary derivatization Quaternary ammonium surfactants (CTAB) catalyzing the thermal decomposition of W-methyl carbamates to liberate methylamine Separation buffer contains the derivatizing components o-phthaldialdehyde/ 2-mercaptoethanol W-methylcarbamates o-Phthaldialdehyde is the most popular fluorescence reactant An Intact capillary can serve consecutively as chamber for separation, decomposition, derivatization, and detection... 

On the other hand, derivatization procedures intended to employ LIE detection of nonfluorescent pollutants are numerous. Thus, various schemes for pesticide derivatization have been successfully used in order to determine carbamates (e.g., on-capillary derivatization with quaternary ammonium surfactants that catalyze their thermal decomposition to yield methylamine and use of a separation buffer containing o-phthaldehyde/2-mercaptoethanol) and phenoxy acid herbicides, pyrethroid insecticides, or anilines (e.g., using precolumn derivatization with different fluorescent tags). 

Ming Li and Sang Hak Lee have reported a CE system integrated with ECL method in the absence of an electric field decoupler for the determination of tri-methylamine (TMA) in fish. ECL from the reaction of analyte and in sim generated Ru(bpy)3 at electrode surface could be produced in the presence of TMA. For ECL detection, a Pt working electrode biased at 1.23 V (vs. Ag/AgCl) potential was employed in a 10 mmol L sodium borate buffer solution, pH 9.2,... 

Figure 18 shows typical cyclic voltammetric i-E curves for 1.0 mM (A) cadaverine (CAD), (B) putrescine (PUT), (C) spermidine (SPMD), and (D) 0.8 mM spermine (SPM) in borax buffer pH 11 (BBpHll) at a microcrystalline diamond thin film deposited from a 0.5% CH4/H2 ratio and 10 ppm B2H6. Similarly shaped curves were observed for several other amines and polyamines (e.g., methylamine, ethylamine, propylamine, ethylenediamine, 1,3-diaminopropane, 1,6-hexamethylenediamine, and... 

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