Salts of amines

Protonation of an amine gives an amine salt. The amine salt is composed of two types of ions the protonated amine cation (an ammonium ion) and the anion derived from the acid. Simple amine salts are named as the substituted ammonium salts. Salts of complex amines use the names of the amine and the acid that make up the salt. 

Amine salts are ionic, high-melting, nonvolatile solids. They are much more soluble in water than the parent amines, and they are only slightly soluble in nonpolar organic solvents. 

Formation of amine salts can be used to isolate and characterize amines. Most amines containing more than six carbon atoms are relatively insoluble in water. In dilute aqueous acid, these amines form their corresponding ammonium salts, and they dissolve. Formation of a soluble salt is one of the characteristic functional group tests for amines. 

The basicity of an amine can be used for purification. The amine is initially more soluble in ether than in water. Addition of dilute HQ converts it to the water-soluble hydrochloride salt. Neutralization with NaOH regenerates the free amine. 

Ephedrine is the principal ingredient in Ma Huang, an herbal remedy originally used to treat asthma. The remedy is now advertised as a natural way to enhance mood, reduce fatigue, and lose weight, but its stimulating effects on the heart can be fatal. 

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C.H.[0].S.Halogen Aryl sulphonyl chlorides C.H.[0].N.S Salts of amines and nitro- ... 

COj liberated. All acids esters which hydrolyse easily, e.g., methyl oxalate (p. 357) salts of amines nitrophenols. 

Salts of amines are generally soluble in water. Upon treatment with 10 per cent, sodium hydroxide solution, the amine will separate if it is insoluble or sparingly soluble in water if the amine is water-soluble, it can be partially volatilised by gentle warming and its presence will be suggested by a characteristic odour. 

Evaluation of the above route against our initial target objectives for the synthesis of taranabant indicated a high level of success, not just for the primary objectives of removing the tin chemistry and chiral chromatography, but for a number of other process improvements (Table 9.2). Of particular note was that the three crystalline intermediates were key for purification, first the phenethylamine salt 12 for the classical resolution, secondly the HC1 salt of amine 2 allowed for upgrade of diastereomeric purity, and finally the API allowed for upgrade of enantiomeric purity via initial removal of racemic material. 

Interesting data were reported in Reference 98 on the transformation of the sulfuric acid salt of amine under conditions of nitrosation (Scheme 3.37). 

UOP in a joint venture with ChevronTexaco developed an additive technology named Alkad . The additive is based on HF salts of amines, which form liquid onium polyhydrogen fluoride complexes with HF, reducing the vapor pressure of the catalyst 65% to more than 80% aerosol reduction is claimed with this additive. As in the ReVap technology, additional separation columns have to be installed. Both additives are claimed to increase the product octane number, especially when propene, isobutylene, and pentenes are employed in the feedstock. 

Combustion rates of the periodate salts of amines exceed those of the corresponding iodate salts. 

Many nitrate salts of amines are highly crystalline, which encourages their use to isolate amines they are also often explosive, which does not. An industrial explosion consequent upon inadvertent isolation of such in part of a production plant, with subsequent overheating is reported [1]. 

Datta, R. L. et al., J. Chem. Soc., 1919, 115, 1006-1010 Many perchlorate salts of amines explode in the range 215-310°C, and some on impact at ambient temperature. Individually indexed compounds are to be found in the group entries ... 

Cationic Detergents Cationic detergents are quarternary ammonium salts of amines with acetates, chlorides or bromides as anions. Cationic part... 

The fuel selected for use with HAN should be totally compatible and therefore, nitrate salts of amines are the natural choice for this purpose. Based on a study with aliphatic, aromatic and heterocyclic amines, aliphatic amines are considered a better choice and a formulation containing the nitrate salt of triethanolamine (TEA), that is, TEAN [(CH2OHCH2)3 NHNOJ is currently in use. HAN-based propellants consist of HAN, water and TEAN. Some typical formulations of LGP are given in Table 4.2 along with their properties. These three propellants differ from one another only in respect of the amount of water which they contain. 

For salts of amines we also obtain strong bands for both the stretching vibrations and the associated bending modes (Table 3.1). 

Salts of amines with inorganic or organic acids are named as substituted ammonium salts, except when the nitrogen is part of a ring system. Examples are... 

Solutions of dmitramic acid can be used to synthesize dinitramide salts with metal hydroxides, carbonates or oxides, and the salts of amine bases ... 

If present, these modify the functional group(s), e.g., in 3-amino-2-chloro-2-butenoic acid, ethyl ester, hydrochloride. Modifications are used for anhydrides, esters, and salts of acids, oxides, sulfides, and selenides of ring systems containing P and As, hydrazones, and oximes of carbonyl compounds, salts of amines, etc. 

Acid salts of amines (and other basic parents) are indexed at the molecular formulae of the amines. Thus, methanamine hydrochloride appears under CHjN (methanamine) and not under CHgClN. 

Salts of amines are generally named by replacing -amine by -ammonium (or -aniline by -anilinium), and adding the name of the anion chloride, nitrate, sulfate, etc.). For example ... 

Feely, W., Lehn, W. L., Boekelheide, V. Alkaline decomposition of quaternary salts of amine oxides. J. Org. Chem. 1957, 22,1135. 

The reagent has been used for the cleavage of picric acid salts of amines. The finely divided yellow picrate is shaken with a mixture of ether and a concentrated aqueous solution of ethanolamine, and the ether solution is drawn off and extracted repeatedly with ethanolamine solution until it is no longer colored. Hiinig and Baron studied the velocity of splitting of quaternary ammonium salts on refluxing with ethanolamine. ... 

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