Victor Meyer method

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. 

A compound of the empirical formula CHj,0 and with a boiling-point of 19s gives the following data as the result of a determination of the vapor density by the Victor Meyer method. 

Problem 19.—Write equations to illustrate the reactions involved in the Victor Meyer method for the differentiation between I, II and III alcohols. Weyl, p 753 (1911). 

It is interesting that, whereas esterification of duroic acid is not effected by the Victor Meyer method, its vinylog, the enol, underwent etherification under these conditions. Heating with methanol in the presence of hydrogen chloride sufficed to convert it into the methyl ether, which in turn is a vinylog of an ester. The enol ether was saponified by aqueous sodium hydroxide, the salt of the enol being formed. 

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

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. 

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... 

Dinitropropane,4 6 1,4-dinitrobutane,6 7 1,5-dinitropen-tane,6 7 and 1,6-dinitrohexane 7 have been prepared only by the method described here, which is that of Victor Meyer. 

This is similar to the use of chlor formic acid and chloi formamide in the preceding syntheses. The method was first used by Victor Meyer. Sulphonic acids are also the starting point for the synthesis of acids through the intermediate acid nitrile as described next. 

The German chemist Victor Meyer (1848-1897), the successor to Robert Wilhelm Bunsen in Heidelberg, developed a method for the determination of molecular masses via vapor density measurements. A sample of diphenylme-thane always lay on his desk in summer. A colleague asked him why his answer was Diphenylmethane melts at 26°C. So if the sample melts I go swimming with my students". 

Vapour-density Determination at Very High Temperatures.—Victor Meyer was able to extend up to 1700° the method of air displacement discovered by him, and thus to... 

Tin(n) chloride has often been used for reduction of arenediazonium salts in acid solution, a procedure that usually gives the tin double salt of the arylhydrazine hydrochloride, these salts being readily decomposed by alkali. This process is simpler than the sulfite method and is very suitable for laboratory purposes the reduction occurs at a low temperature (about 0°), but it fails with diazonium salts of the anthraquinone series, with / -nitrobenzene-diazonium chloride, and with o-benzenetetrazonium dichloride. Victor Meyer exemplifies the use of tin(n) chloride by the reduction of benzenediazonium chloride to phenylhydrazine.12... 

In the method of Victor Meyer the density is determined by finding the volume of the vapor produced from a known weight of substance. As this can be done more readily than the weight of a known volume of vapor can be determined, the method has largely replaced that of Dumas. 

The Importance ( ) of the salts of a,a -d1n1trocyclanones Is Indicated by their facile conversion In high yield to a,w-d1n1tro-alkanes (eq 5). The method Is superior to the well known Victor Meyer reaction In which halogen compounds are treated with silver nitrite. When the ring opening reaction Is performed In reflux-... 

The determination of Molar Masses and Molar Mass Distributions in Polymers has always been a most difficult problem in polymer science. Initially, suitable methods were simply nonexistent (Victor Meyer s method is for gaseous substances), and all the methods subsequently developed proved... 

Victor Meyer described a new method of introducing a carboxyl group into an aromatic molecule by heating the potassium sulphonate with sodium formate, and showed that salicylic acid and other compounds thought to be meta-derivatives are ortho-derivatives. Meyer and E. Ador showed that sulphanilic acid is a para-derivative and they gave a list of the disubstituted benzoic acids according to whether they are ortho-, meta-, or para-compounds. Meyer showed that camphoric acid is a dicarboxylic acid, but did not give a correct structure for camphor. 

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