Meyer, Victor

Molecular Weight Determinations by Physical Methods. Vapour Density. Victor Meyer s Method. 

Note. The above represents the simplest form of Victor Meyer s apparatus. The following modifications may however be applied ... 

In the examples, a nitro group is substituted for a hydrogen atom, and water is a by-product. Nitro groups may, however, be substituted for other atoms or groups of atoms. In Victor Meyer reactions which use silver nitrite, the nitro group replaces a hahde atom, eg, I or Br. In a modification of this method, sodium nitrite dissolved in dimethyl formamide or other suitable solvent is used instead of silver nitrite (1). Nitro compounds can also be produced by addition reactions, eg, the reaction of nitric acid or nitrogen dioxide with unsaturated compounds such as olefins or acetylenes. 

Nitromethane [75-52-5] is produced in China. Presumably a modified Victor Meyer method is being employed. Nitromethane is transported in dmms or smaller containers. Two tank cars of nitromethane exploded in separate incidents in the 1950s. Both explosions occurred in the switching yard of a railroad station. In both cases, essentially adiabatic vapor compression of the nitromethane—air mixture in the gas space of the tank car resulted in the detonation of the Hquid nitromethane. Other nitroparaffins do not, however, detonate in this manner. 

I. A Victor Meyer Apparatus as shown in Fig. 27. It consists of an elongated glass bulb with a narrow stem, and a capillaiy side-tube. It is provided with a wellfitting rubber cork, which can be pressed easily and tightly into the open end... 

In the development of thiophene chemistry three periods can be clearly distinguished the Victor Meyer era, the Steinkopf period, and the modem development starting with the discovery of the synthesis of thiophene from butane and sulfur, making thiophene potentially available in unlimited amounts. Hartough in his well-known monograph, has reviewed the intense and hectic thiophene research toward the end of the 1940 s carried out mainly at the Socony-Vacuum laboratories, but also at many academic institutions. An article by Nord et al. appeared in 1955 in which the research work in thiophene chemistry at Fordham University, as well as progress in general up to 1954, was reviewed. 

Historical. NMe was First prepd by Victor Meyer who treated Me iodide with Ag nitrite and obtained a 90% yield (Ref 2). This proc came to be known as the Victor Meyer reaction (Ref 50). It has also been prepd by the action of Me sulfate on K nitrite (Ref 3). In the Victor Meyer reaction the ratio of NMe to Me nitrite obtained was found to be dependent upon solv, temp, and the reagents used (Ref 5)... 

In exptl work, indirect methods of introducing nitro groups find wide application as, for example, the replacement of a halogen (iodine or bromine in an alkyl iodide or bromide) by the nitro group, by means of silver nitrite (the Victor Meyer reaction)... 

The reaction of alkyl halides with metal nitrites is one of the most important methods for the preparation of nitroalkanes. As a metal nitrite, silver nitrite (Victor-Meyer reaction), potassium nitrite, or sodium nitrite (Kornblum reaction) have been frequently used. The products are usually a mixture of nitroalkanes and alkyl nitrites, which are readily separated by distillation (Eq. 2.47). The synthesis of nitro compounds by this process is well documented in the reviews, and some typical cases are listed in Table 2.3.92a Primary and secondary alkyl iodides and bromides as well as sulfonate esters give the corresponding nitro compounds in 50-70% yields on treatment with NaN02 in DMF or DMSO. Some of them are described precisely in vol 4 of Organic Synthesis. For example, 1,4-dinitrobutane is prepared in 41 -46% yield by the reaction of 1,4-diiodobutane with silver nitrite in diethyl ether.92b 1-Nitrooctane is prepared by the reaction with silver nitrite in 75-80% yield. The reaction of silver nitrite with secondary halides gives yields of nitroalkanes of about 15%, whereas with tertiary halides the yields are 0-5%.92c Ethyl a-nitrobutyrate is prepared by the reaction of ethyl a-bromobutyrate in 68-75% yield with sodium nitrite in DMF.92d Sodium nitrite is considerably more soluble in DMSO than in DMF as a consequence, with DMSO, much more concentrated solutions can be employed and this makes shorter reaction times possible.926... 

This reagent appears quite frequently in the older literature it was used by Victor Meyer in his classic synthesis of thiophene from disodium succinate. It appears that it is (or was) a mixture, with phosphorus heptasulfide (P4S7) being a major component. Louis and Mary Fieser126 quote, with obvious relish, an out-of-doors preparation from red phosphorus and sulfur which often gives an excellent display of fireworks. A standard preparation of 3-methylthiophene uses the heptasulfide.127... 

Quoting R. Demuth and Victor Meyer, in Russell, History of Valency, 166. 

At an early stage it was found that the nitro group had the power of activating the hydrogen atom(s) on the carbon to which the NO2 is attached. Victor Meyer found that primary and secondary (but not tertiary) nitro compounds dissolve slowly in alkali and if alcohol is added an alkali metal salt of the nitro compound is precipitated. Thus the activation of CH by NO2 was associated with incipient acidity and the behaviour of the group in this way was similar to that of certain other groups such as CN, COMe and COOEt6. It was more than twenty years, however, before the incipient acidity of CH adjacent to NO2 was correctly formulated in terms of the tautomerism of nitro and isonitro or aci forms. 

Victor Meyer also discovered the reactions of aliphatic nitro compounds with nitrous acid, which likewise depend on the activation of CH by NO221. Primary nitro compounds give nitrolic acids RC(N02) N0H, secondary nitro compounds give pseudo-nitroles R2C(N0)N02 and tertiary nitro compounds, having no activated CH, do not react. 

Zelinsky, N. A. Ber. Dtsch. Chem. Ges. 1887, 20, 2026. Nikolai D. Zelinsky (1861-1953) was bom in Tyaspol, Russia. He smdied at Gottingen under Victor Meyer, receiving his Ph.D. in 1889. Zelinsky returned to Russia and became a professor at the University of Moscow. On his ninetieth birthday in 1951, he was awarded... 

Sandmeyer, T. Ber. Dtsch. Chem. Ges. 1884, 17, 1633. Traugott Sandmeyer (1854—1922) was bom in Wettingen, Switzerland. He apprenticed under Victor Meyer and Arthur Hantzsch although he never took a doctorate. He later spent 31 years at the firm J. R. Geigy, which is now part of Novartis. 

Primary alkyl iodides and bromides are excellent substrates for the Victor Meyer reaction, providing a route to both substituted and unsubstituted nitroalkanes (Table i. i).63,65,70,7i formation of the corresponding nitrite ester is a side-reaction and so the nitroalkane is usually isolated by distillation when possible. The reaction of primary alkyl chlorides with silver nitrite is too slow to be synthetically useful. Secondary alkyl halides and substrates with branching on... 

Synthesis of nitroalkanes and their derivatives from the reaction of alkyl halides with silver nitrite under the Victor Meyer conditions... 

The synthesis of aliphatic nitro compounds from the reaction of alkyl halides with alkali metal nitrites was discovered by Kornblum and co-workers and is known as the modified Victor Meyer reaction or the Kornblum modification. The choice of solvent in these reactions is crucial when sodium nitrite is used as the nitrite soiuce. Both alkyl halide and nitrite anion must be in solution to react, and the higher the concentration of nitrite anion, the faster the reaction. For this reason, both DMF and DMSO are widely used as solvents, with both able to dissolve appreciable amounts of sodium nitrite. Although sodium nitrite is more soluble in DMSO than DMF the former can react with some halide substrates.Urea is occasionally added to DMF solutions of sodium nitrite to increase the solubility of this salt and hence increase reaction rates. Other alkali metal nitrites can be used in these reactions, like lithium nitrite,which is more soluble in DMF than sodium nitrite but is also less widely available. 

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