Methylammonium hydroxide

Stewart TD, Aston JG (1927) The decomposition of quaternary ammonium hydroxides. Alkoxymethyldiethyl-methylammonium hydroxides. J Am Chem Soc 49(7) 1718-1728... 

A diatomaceous earth column was used to separate halcinonide from excipients . The formulation is mixed with column packing material and then is transferred to the top of the column. Steroidal material is eluted with benzene (CAUTION) under a well-ventilated hood and then quantitated using thin layer chromatography60 0r tetra-methylammonium hydroxide l colorimetry. 

Polynitroaromatic compounds were reported to undergo color reactions with numerous bases, such as ammonia in methanol [3] and aqueous solution of tetra-methylammonium hydroxide [10]. 

Note. (1) In a modified procedure8 using triethylene glycol as solvent and benzyltri-methylammonium hydroxide (Triton B ) as the base catalyst, the reaction may be completed in a very short time. 

Filley, T.R. (2003) Assessment of fungal wood decay by lignin analysis using tetra-methylammonium hydroxide (TMAH) and 13-labelled TMAH thermochemolysis. In Wood Deterioration and Preservation Advances in Our Changing World (Goodell, T., Nicholas, A., and Schultz, C., eds.), pp. 119-139, ACSociety, Series 845, American chemical Society, Washington, DC. 

L. Murthy, E. E. Menden, P. M. Eller, H. G. Petering, Atomic absorption determination of zinc, copper, cadmium, and lead in tissues solubilized by aqueous tetra-methylammonium hydroxide, Anal. Biochem., 53 (1973), 365D372. 

Ruthenium compounds have been extensively studied as catalysts for the aerobic oxidation of alcohols [142]. They operate under mild conditions and offer possibilities for both homogeneous and heterogeneous catalysts. The activity of common ruthenium precursors such as RuCl2PPh3, can be increased by the use of ionic liquids as solvents (Fig. 4.58). Tetramethylammoniumhydroxide and aliquat 336 (tricaprylylmethylammonium chloride) were used as solvent and rapid conversion of benzyl alcohol was observed [145]. Moreover the tetra-methylammonium hydroxide/RuCl2(PPh3)3 could be reused after extraction of the product. 

Thermal decomposition of quaternary ammonium salts and bases is most valuable in structural investigations of amines, particularly heterocyclic secondary amines (Hofmann exhaustive methylation). The course of the elimination (A or B) is determined by the nature of the four alkyl groups on the nitrogen atom. The reaction has found little use in the synthesis of pure olefins. The yields are low even when three of the alkyl groups are methyl radicals. Carbon-skeleton rearrangement does not occur. Thus, the only olefin obtained by pyrolysis of pinacolyltri-methylammonium hydroxide, (CHj),CCH(CHj)N(CHj)j OH, is /-butylethylene (50%). ... 

The catalytic solutions were characterized by potentiometric titration of the siloxanolate groups with alcoholic HCl. Titration with acid generally yielded two end points The first end point was attributed to the siloxanolate group, and the second was attributed to the carbonate species. Previous workers (12) have also reported two end points for the titration of tetra-methylammonium hydroxide (TMAH) with HCl, with phenolphthalein and methyl orange as indicators. They attributed the end points to hydroxide and carbonate components, because TMAH readily absorbs carbon dioxide from the air. The carbonate species was reasonably assumed to have no catalytic effect on the siloxane equilibration reactions. 

McKinney D. E., Bortiatynski J. M., Carson D. M., Clifford D. J., de Leeuw J. W., and Hatcher P. G. (1996) Tetra-methylammonium hydroxide (TMAH) thermochemolysis of the aliphatic biopolymer cutan insights into the chemical structure. Org. Geochem. 24, 641-650. 

Archer, D. A. Behavior of quaternary salts under reduced pressure. II. Decomposition of the N-methylammonium hydroxides of benzyl-, dibenzyl-, and diphenylmethylamines. J. Chem. Soc. 0.1971,1329-1331. 

Winterstein esters are easily turned into >-cinnamates by the action of acids (H silica gel) [32]. For preparative purposes the reaction has been carried out using the Hoffmann elimination of the corresponding methylammonium hydroxides [27] or the Cope elimination of the corresponding tf-oxides [SI], The latter procedure is more convenient, since, if the reaction is carried out in THF, elimination of dimethylhydroxylamine takes place spontaneously at room temperature. If only a moderate excess of peracid is employed, the exocyclic double bond at C-4 is not affected [30], The transformation of Winterstein esters into cinnamates can be very useful for separation purposes. Thus, whereas taxine B (2a) and isotaxine B (2b) are difficult to separate by HPLC, their corresponding cinnamates can be separated by column chromatography... 

N,N-dimethylacetamide)tetra-methylammonium hydroxide + butyl iodide theophylline91,98... 

An important application is the preparation, from trimethylamine and DMC, of electronic-grade tetra-methylammonium hydroxide, free from chloride ion, by electrolysis of the hydrogen carbonate. 

Mobile phase MeCN MeOH water acetic acid 30 15 54.5 0.5, containing 10 mM tetra-methylammonium hydroxide... 

Muscarin— c lo,) [n,OH = CsHisXOj—is a substituted tetra-methylammonium hydroxid related to eholin, neurin and ainani-tin, from which it may be obtained by oxidation. 

Ethylene glycol, 2,6-NDA, terephthalic acid (TPA), and IPA are condensed using 10% aqueous tetra-methylammonium hydroxide solution. Antimony trioxide and cobalt acetate are used as catalysts. The reaction is conducted in an inert atmosphere initially under pressure, up to 260 °C, then the pressure is reduced in steps and the temperature is increased up to 274-288 °C. 

For anion analysis, the regenerant must supply a source of hydrogen ions to convert the eluent anions to a less conductive form. The most common regenerant is dilute sulfuric acid, whereas for cation analysis, the most common regenerant is hydroxide (sodium, potassium, or tetra-methylammonium hydroxide). 

The equilibrium constant for the reaction of an amine with water, K, has the following form, illustrated for the reaction of methylamine with water to give methylammonium hydroxide ... 

The detection of sodium ions in the presence of chlorides, nitrates, phosphates, and sulfates and high concentrations of ammonium, lithium, potassium and magnesium salts can be carried out with an aqueous ethanolic solution of a-methoxyphenylacetic acid (I) partially neutralized with tetra-methylammonium hydroxide. 

The reduction of papaverine methiodide has been facilitated by the use of new reagents. Its reduction (or of a similar salt) with sodium borohydride in aqueous methanol is now the best method for the production of racemic laudanosine (167) (Section III, F). If pyridine is employed as a solvent 1,2-dihydro-iV-methylpapaverine also is obtained in good yields (166). The 1,2-dihydro derivative is the main product when lithium aluminum hydride is employed although the tetrahydro compound is probably formed in small amounts (169). Polarographic reduction of papaverine and 3,4-dihydropapaverine in aqueous tetra-methylammonium hydroxide gave half-wave potentials of — 1.92 V and — 1.62 V, respectively (170). 

Filtration only filter washed with MeOH Soxhlet extraction with MeOH SPE on anion exchanger (elution with 95 5 MeOH/con HCl) derivatization further cleanup with alumina, silica, copper SPE on graphitized carbon black (elution with 9 1 CH2Cl2/MeOH,0.01 M in tetra-methylammonium hydroxide) derivatization further cleanup with alumina SPE on graphitized carbon black (elution with 9 1 CH2Cl2/MeOH, 0.02 M in tetra-butylammonium bisulfate) butyl esters formed in GC injection port Liquids. SPE on Cm resin for the lower concentrations and Cm disks for the higher solids MeOH extraction extracts were cleaned up by anion exchange and additional SPE on Cm... 

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