Containers methylamine

Example 1 Due to a small leak, the workplace contains methylamine (CH5N) at a concentration of 13.7 ppm (parts per million, volume) in air. 

Propose a series of steps using ion-exchange resins for the isolation of glucose-6-phosphate from a solution containing methylamine, sodium acetate, glucose, and glucose-6-phosphate. 

Sunvex 100A, 200 and 220 contain methylamine nitrate. Bnergcl MA 7 contains ethanolamtne mononitrate. IRECO explosives are sensitized with Al. 

Caution.—If the ethanol used to extract the methylamine hydrochloride is not absolute, i.e., if it contains traces of water, considerably less than the above suggested quantity will be required for the extraction, because the solubility of the hydrochloride will be markedly increased by the water present. The recrystallised material will now, however, contain traces of ammonium chloride. 

Dimethylaminomethylindole (gramine). Cool 42 5 ml. of aqueous methylamine solution (5 2N ca. 25 per cent, w/v) contained in an 100 ml. flask in an ice bath, add 30 g. of cold acetic acid, followed by 17 -2 g. of cold, 37 per cent, aqueous formaldehyde solution. Pour the solution on to 23 -4 g. of indole use 10 ml. of water to rinse out the flask. Allow the mixture to warm up to room temperature, with occasional shaking as the indole dissolves. Keep the solution at 30-40° overnight and then pour it, with vigorous stirring, into a solution of 40 g. of potassium hydroxide in 300 ml. of water crystals separate. Cool in an ice bath for 2 hours, collect the crystalline solid by suction flltration, wash with three 50 ml. portions of cold water, and dry to constant weight at 50°. The yield of gramine is 34 g. this is quite suitable for conversion into 3-indoleacetic acid. The pure compound may be obtained by recrystaUisation from acetone-hexane m.p. 133-134°. 

PoIya.mines are condensation polymers containing nitrogen they are made by a variety of synthetic routes. Most of the commercial polyamines are made by reaction of epichlorohydrin with amines such as methylamine [25988-97-0] or dimethylamine [39660-17-8] (18,19). Branching can be increased by a dding small amounts of diamines such as ethylenediamine [42751-79-1]. A typical stmcture of this type of polyamine is stmcture (9). 

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). ... 

Dibenzo[d,g][l,5]telluroazocines 65 are the only representatives of Te, N-containing eight-membered heterocycles known thus far. Treatment of bis(2-bromomethylphenyl)tellurium dibromide 66 with methylamine followed by reduction of the reaction mixture with sodium sulfide gives, instead of the expected... 

Methylamine contains an electronegative nitrogen atom with two lone-pair electrons. The dipole moment thus points generally from -CH3 toward NH2. 

Both PS-A and PS-B have a tendency to hydrate like panal, and they also form adducts with methylamine. The adducts, PS-A/MA and PS-B/MA, are prepared by incubating PS-A or PS-B in 75 % methanol containing an excess amount of methylamine hydrochloride plus some sodium acetate to neutralize the HC1, at 45°C for 30 min. The adducts can be purified by HPLC on a PRP-1 column (80% acetonitrile containing 0.05% acetic acid). Their chemical structures have been determined by NMR and mass spectrometry as shown in Fig. 9.8 (p. 288). Both adducts are colorless and show an absorption maximum at 218 nm. 

Purification of the activation products (PMs). The methylamine activation product dissolved in methanol is purified by chromatography, first on a column of silica gel using a mixed solvent of chloroform/ethanol, followed by reversed-phase HPLC on a column of divinylbenzene resin (such as Jordi Reversed-Phase and Hamilton PRP-1) using various solvent systems suitable for the target substance (for example, acetonitrile/water containing 0.15% acetic acid). 

In a 2-1. flask provided with a mechanical stirrer, separatory funnel, and thermometer, are placed 189 g. (2 moles) of chloro-acetic acid and 150 cc. of water. The flask is cooled in ice water, and a cold solution of 160 g. (4 moles) of sodium hydroxide in 500 cc. of water is added, with stirring, at such a rate that the temperature does not exceed 30° (Note 1). AfLer all the alkali has been added, the cooling bath is removed, and an aqueous solution (Note 2) containing 31 g. (1 mole) of methylamine is added slowly. The reaction is exothermic, and the temperature is kept below 50° by occasional immersion of the flask in ice water. After all the methylamine has been added, the solution is allowed to stand for two hours to complete the reaction. 

The decomposition of a number of perchlorates containing substituted ammonium groups (various methylamines, guanadine etc.) [935—939] resemble the mechanism proposed for AP decomposition in that proton transfer is identified as the initial step. 

Conversion of methanol into formaldehyde by methanol dehydrogenase. A complex array of genes is involved in this oxidation and the dehydrogenase contains pyrroloquinoline quinone (PQQ) as a cofactor (references in Ramamoorthi and Lidstrom 1995). Details of its function must, however, differ from that of methylamine dehydrogenase that also contains a quinoprotein—tryptophan tryptophylquinone (TTQ). 

Methylamine hydrochloride method. Place 100 g. of 24 per cent, methyl-amine solution (6) in a tared 500 ml. flask and add concentrated hydrochloric acid (about 78 ml.) until the solution is acid to methyl red. Add water to bring the total weight to 250 g., then introduce l50 g. of m%a, and boil the solution gently under reflux for two and three-quarter hours, and then vigorously for 15 minutes. Cool the solution to room tempara-ture, dissolve 55 g. of 95 per cent, sodium nitrite in it, and cool to 0°. Prepare a mixture of 300 g. of crushed ice and 50 g. of concentrated sulphiuic acid in a 1500 ml. beaker surrounded by a bath of ice and salt, and add the cold methylurea - nitrite solution slowly and with mechanical stirring and at such a rate (about 1 hour) that the temperature does not rise above 0°. It is recommended that the stem of the funnel containing the methylurea - nitrite solution dip below the siu ace of the acid solution. The nitrosomethylurea rises to the siuface as a crystalline foamy precipitate. Filter at once at the pump, and drain well. Stir the crystals into a paste with about 50 ml. of cold water, suck as dry as possible, and dry in a vacuum desiccator to constant weight. The yield is 55 g. (5). 

Oxime carbamates have high polarity and solubility in water and are relatively chemically and thermally unstable. They are relatively stable in weakly acidic to neutral media (pH 4-6) but unstable in strongly acidic and basic media. Rapid hydrolysis occurs in strongly basic aqueous solutions (pH > 9) to form the parent oxime/alcohol and methylamine, which is enhanced at elevated temperature. Additionally, oxime carbamates are, generally, stable in most organic solvents and readily soluble in acetone, methanol, acetonitrile, and ethyl acetate, with the exception of aliphatic hydrocarbons. Furthermore, most oxime carbamates contain an active -alkyl (methyl) moiety that can be easily oxidized to form the corresponding sulfoxide or sulfone metabolites. 

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