Amines trimethylamine

The nitroso-group in the p-position has a remarkable influence in making possible the hydrolytic removal of the dimethylamino group from the benzene ring. The reaction is used technically for the preparation of secondary amines. (Trimethylamine is obtained by heating ammonium chloride with formaldehyde.)... 

Strong Base Anion Exchangers. As in the synthesis of weak base anion exchangers, strong base resins are manufactured from styrenic as well as acrylic copolymers. Those based on copolymers of styrene and divinylbenzene are chloromethylated and then aminated. These reactions are the same as for the styrenic weakbase resins. The essential difference is the amine used for amination. Trimethylamine [75-50-3], N(CH3)3, and A/,A/-dimethylethanolamine [108-01-0], (CH3)2NCH2CH2OH, are most commonly used. Both form quaternary ammonium functional groups similar to (8). 

In 1851, A.W. Hofmann discovered that when trimethylpropylammonium hydroxide is heated, it decomposes to form a tertiary amine (trimethylamine), an olefin (propene), and water. Widespread use of this transformation did not occur until 1881, when Hofmann applied this method to the study of the structure of piperidines and nitrogen-containing natural products (e.g., alkaloids). " The pyrolytic degradation of quaternary ammonium hydroxides to give a tertiary amine, an olefin and water is known as the Hofmann elimination. The process involves three steps 1) exhaustive methylation of the primary, secondary or tertiary amine with excess methyl iodide to yield the... 

The reaction of trifluoroacetic anhydride on the A(-oxides of 3)5-dimethytamino-steroids (51) (e.g., iV-methyl-5a-dihydroparavallarine) leads to the immonium salts (52) and (53), which can be hydrolysed to the 3-keto- or the 3-methylamino-steroid, respectively. " This reaction is generally applicable to other amines trimethylamine oxide is converted into iViV-dimethylformaldimmonium tri-fluoroacetate (54), which is an excellent Mannich reagent. ... 

Displacement of halides can be catalysed by amines - trimethylamine, pyridine and DABCO have been used. Mechanistically, the catalysis involves formation of an intermediate quaternary ammonium salt that is more reactive towards nucleophiles than the starting halide. The intermediate quaternary salts can be isolated, if required. Trimethylamine gives the most reactive quaternary salt, but DABCO can be more convenient. The relative reactivities for nucleophilic displacement at C-6 are trimethylamine DABCO chlorine = 100 10 1. Cyano and fluorine are amongst the groups that have been introduced in this way. 

The catalysts for the alkoxylation of bisphenol A are alkali hydroxides (KOH, NaOH) and tertiary amines (trimethylamine, dimethylaminoethanol, dimethylcyclohexylamine). Of course, the polyether diols obtained in KOH catalysis must be purified by removing the potassium ions, using conventional procedures. 

Figure 5.39 Change in transport numbers of bromide, nitrate and sulfate ions relative to chloride ions in anion exchange membranes reacted with various amines. ( ) trimethylamine (H) ethylenediamine and then trimethylamine until electrical resistance of the membrane attained was ca. 10 Qcm2 (2 h) (3) tetraethyle-nepentamine and then trimethylamine until the resistance attained was ca. 10 Qcm2 (32 h) ( ) polyethyleneimine and then trimethylamine until the resistance attained was ca. 10 Qcm2 (64 h). The membranes were immersed in 1.0 N hydrochloric acid solution for 2 h before electrodialysis and PaA was measured by electrodialysis of 1 1 mixed salt solutions (concentration of sodium ions 0.04 N) at 1.0 mA cm 2 at 25.0 °Cfor 60 min.

The tertiary amines, trimethylamine and triethylamine, and the secondary amines, dimethyl, diethyl, and dipropyl, react with zirconium tetrachloride to form 1 2 addition compounds, whereas primary amines undergo ammonolysis reactions (151). 

The potential use of amine concentration as a criteria to assess freshness in finfish and shellfish has been discussed by many researchers. The volatile amines trimethylamine (TMA) and dimethylamine (DMA) have been widely used as indicator of heshness of marine fish (Castell et al, 1971). Tables X and XI give the concentration of TMA and DMA in herring and... 

Karpas, Z. Litvin, O. Cohen, G. Mishin, J. Atweh, E. Burlakov, A., The reduced mobility of the biogenic amines trimethylamine, putrescine, cadaverine, spermidine and spermine, Int. J. Ion Mobil. Spectrom. 2011, 14, 3-6. 

Fig. 3. Comparison of gas and aqueous basicity of amines. AG for same reactions as in Figure 2. O ammonia, methyl amine, C dimethyl amine,, trimethylamine.

The compound formed here is dimethylamine. Further reaction with bro-momethane produces the tertiary amine, trimethylamine. 

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