Griesheim method

According to the German (Griesheim) method [60] tetryl is manufactured in two stages first dinitromethylaniline is prepared and this is then nitrated. 

Sulphitation of dinitrobenzene (Griesheim method) is carried out in the SMne washing tank. Cold water is run in until the temperature falls to 66°C. Then a solution of sodium sulphite, prepMed by mixing 1000-1100 1. of a 40% solution of sodium hydrogen sulphite with 400-500 kg of 33% sodium hydroxide, is added. 

In the Griesheim method the oxidation of trinitrotoluene is accomplished by means of chromic acid in the presence of sulphuric acid, a temperature 40-50°C being maintained. By diluting the solution with water, trinitrobenzoic acid is precipitated. Boiling the acid in water results in the evolution of C02 and the formation of trinitrobenzene. 

The Griesheim method is generally used for the laboratory preparation of sym-trinitrobenzene. However, it is too expensive to be applied in industry. Trinitrobenzene prepared in this way is much more costly than trinitrotoluene, whereas the gain in explosive power obtained is relatively small. 

According to the Griesheim method of nitration of p- chloronitrobenzene to l-chloro-2,4-dinitrobenzene, 4500 kg of molten p- chloronitrobenzene (m. p. 82.4°C) is introduced into a nitrator, followed by 5700 kg of a nitrating mixture,... 

Nitration with concentrated acid by the Griesheim method is effected in the following way. 

Nitration ofp chIoronitrobenzene to l-chloro-2,4>dinitrobenzene Nitration of chlorobenzene to chlorodinitrobenzene (Griesheim method) Mononitration Dinitration... 

Accdg to USP 422415(1890), Dr Emmens proposed, in order to lower the mp of Emmensite, incorporating some aromatic mononicro-compd, such.as Nitrobenzol. The same method was patented in Germany by the Chemische Fabrik Griesheim (Ref 1, p 256)... 

Preparation from a- trinitrotoluene. In 1893 a patent was granted to the Chemische Fabrik Griesheim [47a] for the manufacture of sym-trinitrobenzene from trinitrotoluene. The method was based on the fact observed by Tiemann [48] Mid by Claus and Becker [49], that trinitrotoluene can be oxidized with nitric acid to trinitrobenzoic acid, the latter being readily decarboxylated to form sym-trinitrobenzene ... 

The Griesheim (I. G. Farbenindustrie) method, described below, may be cited as an example of an industrial method of preparing and separating nitrotoluenes. 

At Griesheim a continuous method of nitrating toluene to nitrotoluenes was also used. The nitration unit consisted of two nitrators connected by their bottom outlets, fed with mixed acid of the same composition as in the batch process. 

The nitration of chlorobenzene was first mentioned in 1862 by Riche [6], Later the reaction was studied by Sokolov [7] and Holleman and de Bruyn [8], Junglleisch [9] was the first to describe the method of preparation of chlorodinitrobenzene from o- or p- chloronitrobenzene. Laubenheimer [10] investigated the products of the nitration of m- chloronitrobenzene, and Ostromyslenskii [11] determined the structure of the products obtained by Jungfleisch, i.e. of 1,2,4- and 1,2,6-chloro-dinitrobenzenes. Finally in 1894 the Griesheim factory reported [12] on a method of preparing chlorotrinitrobenzene by direct nitration of chlorobenzene. 

Gnehm [22] prepared hexanitrodiphenylamine by the nitration of diphenyl-amine with nitric acid, while Mertens [23] used a mixture of anhydrous nitric acid with concentrated sulphuric acid for the purpose. This method was applied in 1910 for the commercial preparation of hexyl. Since the yields obtained were too low (some 60% of the theoretical), during World War I a method patented in 1895 by the Griesheim Works was introduced, the starting materials being chlorodi-nitrobenzene and aniline. The method consists in the preparation of dinitrodi-phenylamine (m. p. 156-167°C) which is then nitrated in two stages, to obtain first tetranitrodiphenylamine (m. p. 199°C) and then hexyl ... 

Membrane for Separation of Xenon from Oxygen and Nitrogen and method of Using Same, Messer Griesheim GmbH, Germany. WOOO/33949. Date of publication 15 June 2000. 

The Griesheim Eldrtron Company use a dosed diaphragm cell for preparing metallic permanganates, which is fitted with tubes for the escape of electrolytic gas. Their method for preparing the calcium salt is as follows The cathode compartment contains caustic potash solution, and the anode compartment is filled with saturated manganate... 

The solubility of carbon dioxide (Messer-Griesheim, 5.0) in polymethylmethacrylate (PMMA) Makrolon 2400 (Bayer AG), cp. Tab. 5.3 and [5.29], and the swelling of the polymer have been measured at T=308 K using the oscillometric-manometric method [5.27]. Results are presented in Figure 5.19. The reduced masses (Q =m -p V ) resulting from manometric measurements, cp. Eq. (5.74), are indicated by ( ). As clearly can be seen, these data increase at low pressures (p < 3.5 MPa) to have a maximum at p = 3.5 MPa, then to decrease and even assume negative values... 

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