Fused organic salts. VII. System tetra-n-pentylammonium nitrate-silver nitrate. Melt stability. Silver nitrate-carbon tetrachloride

Gordon, John E.; Varughese, P.

doi:10.1021/jo00961a015

Cited by 5 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A chemical reaction between carbon tetrachloride and silver nitrate in molten tetrapentylammonium nitrate was reported by Gordon and Varughese to produce a nitrating agent which was capable of reacting with tertiary aliphatic amines to produce N-nitrosamines (10).…”

Section: Applicationsmentioning

confidence: 99%

Quarternary ammonia salts: Some recent applications in organic synthesis

Varughese¹

1977

J. Chem. Educ.

Self Cite

View full text Add to dashboard Cite

Some recent applications in organic synthesisMost undergraduate organic textbooks give only a passing reference to the unique class of compounds called quaternary ammonium salts. They are often referred to merely as the final products of exhaustive alkylation of primary amines. A student may get the erroneous impression that they are of no particular use in chemistry and that, being ionic, they are all soluble in water. Many textbooks make unqualified statements about their thermal stability.In the last ten years there has been a great upsurge of interest in the chemistry of quaternary ammonium salts. As a result, a number of interesting applications of molten quaternary ammonium salts have resulted (1-5). More recently, Starks reported that a small amount of quaternary ammonium salt added to certain two-phase organic reaction mixtures would catalyze these reactions to a remarkable extent (6). This phenomenon of phase-transfer catalysis has spurred considerable study in the United States, Europe, and Japan as evidenced by the large number of papers published in this area during the past four years.Part of the attractiveness of this area of research stems from the fact that it is within the scope and reach of most institutions where undergraduate research in chemistry is encouraged. No expensive and sophisticated instruments are required, and most of the chemicals needed are relatively inexpensive. Quaternary Ammonium SaltsQuaternary ammonium salts are compounds of the general formula R4N+X_ where R is alkyl, aryl, or aralkyl group and X is any anion. The R groups could be identical or different.These organic salts are ionic compounds which are made from primary, secondary or tertiary amines and an appropriate alkyl halide, sulfate, or some other similar compound carrying an excellent leaving group. Synthesis from a primary amine involves treatment with an excess of alkyl halide in methanol, acetonitrile, ethyl acetate, or benzene solution in the presence of a mild base. The last alkylation step is recognized as the Menshutkin reactionMany of these salts are crystalline solids at room temperature and are stable at their melting points for short periods of time. Low-melting salts may not crystallize easily at room temperature and a few salts are liquids at laboratory temperature (6-9). Their melting points depend on molecular weight, symmetry of the cation, and the nature of the anion. Thermal stability is related to the nucleophilicity of the anion. Strongly nucleophilic anions promote reverse Menschutkin reaction. Elimination products will also be obtained if the tertiary amine formed in the reverse Menschutkin reaction is not promptly removed from the reaction mixture. Hygroscopic properties vary in poorly defined fashion.Low-molecular weight salts up to Cg-salts are highly soluble in water, but beyond that the solubility in water decreases rapidly. However, incorporation of ether linkages in one or more of the alkyl groups tends to increase the solubility in water remarkably. Quaternary ammonium salts are gener...

show abstract

Section: Applicationsmentioning

confidence: 99%