124-40-3 Dimethylamine

The acute oral and dermal toxicity of cyclohexylamine was moderate in test subjects. The toxic effects include nausea, vomiting, and degenerative changes in the brain, liver, and kidney. Inhalation of its vapors at high concentrations may cause a narcotic effect. 

LD50 value, oral (rats) 156 mg/kg LD50 value, skin (rabbits) 277 mg/klg 

There is no evidence of carcinogenicity in animals or humans caused by cyclohexylamine. 

Flammable liquid flash point (open cup) 32°C (90°F) autoignition temperature 293°C (560°F) vapor density 2.4 (air =1) the vapor is heavier than air and can travel a considerable distance to a source of ignition 

Cyclohexylamine vapors form explosive mixtures with air explosive limits data are not available. Vigorous reactions may occur when the amine is mixed with strong acids or oxidizers. 

Trimethylamine is a colorless, flammable, easily condensible gas with a pungent, ammoniocal odor. The commercial product is on aqueous solution containing 25% by weight of trimethylamine. It is very soluble in water and is used os a warning agent in bottled gas, as on insect attroclont, and in organic synthesis. 

Boiling point Critical temperature Critical pressure Decomposition temperature Dielectric constant at 4 C. Electrical conductivity 

Heot of evoporization at BP Melting point Specific grovily ot -5 C. Surfoce tension ot -4 C. Solubility In water ot 19 C. 

1 liter of aqueous saturated solution contoins 410 g. of amine 3.208 millipoises Not more than 0.2% by wt. of solution 

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Colourless solid m.p. 132-134 C. An important intermediate for preparing indole derivatives, produced by treating indole under Mannich reaction conditions with methanal and dimethylamine. 

CH3)2N]3P0. M.p. 4°C, b.p. 232"C, dielectric constant 30 at 25 C. Can be prepared from dimethylamine and phosphorus oxychloride. Used as an aprotic solvent, similar to liquid ammonia in solvent power but easier to handle. Solvent for organolithium compounds, Grignard reagents and the metals lithium, sodium and potassium (the latter metals give blue solutions). 

Dimeihylamine, C2H7N, (CH3)2NH. Colourless, inflammable liquid with an ammoniacal odour, mp -96" C, b.p. 7°C. Occurs naturally in herring brine. Prepared in the laboratory by treating nitrosodimetbyl-aniline with a hot solution of sodium hydroxide. Dimethylamine is largely used in the manufacture of other chemicals. These include the solvents dimethylacetamide and dimethyl-formamide, the rocket propellant unsym-metrical dimethylhydrazine, surface-active agents, herbicides, fungicides and rubber accelerators. 

It reduces to 4-aminodimethylaniline and gives dimethylamine with hot sodium hydroxide solution. It is prepared by the action of nitrous acid upon dimethylaniline at 0 C. 

Place about i g. of the base in a test-tube, and cover with concentrated (about 20%) sodium hydroxide solution. Bring the mixture gently to the boil, keeping the test-tube lightly closed with the finger meanwhile to prevent undue escape of vapour.. A.s the solution boils a strong fishy odour of dimethylamine is detected, and white fumes form when the test-tube is held near an open bottle of concentrated... 

The Mannich Reaction involves the condensation of formaldehyde with ammonia or a primary or secondary amine and with a third compound containing a reactive methylene group these compounds are most frequently those in which the methylene group is activated by a neighbouring keto group. Thus when acetophenone is boiled in ethanolic solution with paraformaldehyde and dimethylamine hydrochloride, condensation occurs readily with the formation of... 

Note. Dimethylamine hydrochloride is a deliquescent substance the sample if damp must be dried in a vacuum desiccator and then rapidly weighed before use. 

Add 5 ml. (5 g.) of acetophenone, 1-25 g. of finely powdered paraformaldehyde, and 3 5 g. of dry dimethylamine hydrochloride to 8 ml. of absolute ethanol, and then boil the mixture under reflux for 1-5 hours. Filter the solution (which is now almost entirely clear) through a preheated filter-funnel, and cool the filtrate in ice-water with stirring. The propiophenone hydrochloride rapidly separates as white crystals filter oflF the crystals at the pump and recrystallise from a small quantity of ethanol m.p. 155-156°. Yield, 2 5 g. 

If the metlijlainiiie hydrochloride in solution from the previous re.action be heated with a further quantity of formalin at 115° dimethylamine hydrochloride (dimethylammonium chloride) may be isolated ... 

The p-substituted amino ketones can be reduced readily to the more stable P-dialkylamino alcohols, many of which are useful local anaesthetics. Thus the local anaesthetic Tutocaine is made from the Mannich base derived from formaldehyde, methyl ethyl ketone and dimethylamine, followed by reduction and conversion into the p-aminobenzoate ... 

Benzoylpropionitrile. To a mixture of 21 4 g. of p dimethylamino propiophenone hydrochloride, 13 0 g. of potassium cyanide in a 500 ml. flask, add 260 ml. of boiling water heat the heterogeneous mixture under reflux for 30 minutes. Part of the dimethylamine, which is eliminated in the reaction, distils collect this in dilute hydrochloric acid. Cool the reaction mixture in ice the oil sohdifies and crystals form from the aqueous layer. Collect the solid (crude p benzoylpropiouitrile, 10-5 g.) by suction filtration and recrystallise it from benzene - light petroleum (b.p. 40-60°) it separates as almost colourless blades, m.p. 76°. 

Indole (I) condenses with formaldehyde and dimethylamine in the presence of acetie acid (Mannich reaction see Section VI,20) largely in the 3-position to give 3 dimethylaminomethylindole or gramine (II). The latter reaets in hot aqueous ethanol with sodium cyanide to give the nitrile (III) upon boiling the reaction mixture, the nitrile undergoes hydrolysis to yield 3-indoleaeet-amide (IV), part of which is further hydrolysed to 3-indoleacetic acid (V, as sodium salt). The product is a readily separable mixture of 20 per cent, of (IV) and 80 per cent, of (V). 

Transfer the filtrate to a ceramic evaporating dish and heat on a water bath until a crystalline scum forms on the top. Cool the dish quickly then filter the mess on the vacuum Buchner to yield 96g of Methylamine Hydrochloride. Concentrate the filtrate once again to obtain a second crop of crystals, -IQg. Concentrate the filtrate a third time as far as possible using the water bath, then store the dish in a vacuum dessicator loaded with Sodium Hydroxide in the bottom for 24 hours. Add Chloroform to the residue left in the crucible to dissolve out Dimethylamine Hydrochloride (distill off the Chloroform to recover - good stuff) then filter on the venerable old vacuum Buchner funnel to yield an additional 20g of Methylamine Hydrochloride, washing the crystals in the funnel with a small poiiion of Chloroform ( 10mL). 

In the flask were placed 60 g of powdered paraformaldehyde, 100 ml of dioxane and 3 g of copper(II) acetate and 0.3 mol of liquid dimethylamine was added at -20 C. The temperature was allowed to rise gradually to 40-45°C with occasional cooling and when the reaction had subsided, the mixture was cooled to 20°C and a second portion of 0.3 mol of the amine was added. When this had reacted, the remainder of the 2.0 mol of dimethylamine was added in the same way. The mixture... 

The 7V-methylbenzo[( e]quinoline 426 was prepared by trapping the insertion product of an internal alkyne with a tertiary dimethylamine. One methyl group is eliminated. The dimethylaminonaphthalene-Pd complex 427 is an active catalyst and other Pd compounds are inactive[290a]. 

Naming a Coordination Compound. To name a coordination compound, the names of the ligands are attached directly in front of the name of the central atom. The ligands are listed in alphabetical order regardless of the number of each and with the name of a ligand treated as a unit. Thus diammine is listed under a and dimethylamine under d. The oxidation number of the central atom is stated last by either the oxidation number or charge number. 

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