Übersetzung für "Nitriersäure" in Englisch

Step 2, the nitration step, is carried out with nitrating acid.

The 3-fluorobenzoic alkyl ester dissolved in sulfuric acid is then treated with nitrating acid.

During the reaction with nitrating acid, excessive temperatures should be avoided.

Concentrated nitric acid or nitrating acid are preferably used.

Using nitrating acid, the aromatic rings could be nitrated at least partially.

Separate introduction of the toluene and of the nitrating acid is likewise possible.

Benzene is metered into this nitrating acid.

Add 1 ml benzene to the cooled off nitrating acid.

One can dispose of the nitrating acid as halogene-free organic waste.

The elemental halogen, the customary halogenation catalysts as well as the nitrating acid are common chemicals.

1 ml 100 percent nitrating acid is then added by drops and it is stirred for 17 hours at room temperature.

The nitrating acid used contains 11.1% by weight of nitric acid, 68.5% by weight of sulfuric acid, and 20.4% of water.

Nitric acid and nitrating acid are preferably suitable as nitrating agents for carrying out the preparation process (b).

The dinitration is preferably carried out using a mixture of sulfuric acid and nitric acid (nitrating acid).

The toluene is preferably dispersed in the nitrating acid by means of a dispersing element such as, e.g., a jet disperser.

There, the organic phases containing mononitrotoluene (stream 26 + 31) are reacted with nitrating acid there to form dinitrotoluene.

The nitrating acid as well as the 2-ethyl-1-hexanol had been cooled down to 20° C. before being mixed.

The first route according to the invention for the preparation of those compounds according to the invention of general formula I, wherein R signifies the methanesulphonyl or nicotinoyl radical, consists in that the corresponding 1.4;3.6-dianhydrohexitol is esterified with nitric acid, nitrating acid or with a mixture of nitric acid and acetic anhydride/acetic acid, possibly in the presence of urea, whereby, in each case, a mixture of the corresponding mononitrate or mononitrates and of the dinitrate result.

According to this second process according to the invention, starting, for example, from 1.4;3.6-dianhydro-D-glucitol, by reaction with methanesulphonic acid chloride there is first prepared 1.4;3.6-dianhydro-D-glucitol 5-methanesulphonate and the latter reacted with nitric acid, nitrating acid or with a mixture of nitric acid, glacial acetic acid and acetic anhydride to give 1.4;3.6-dianhydro-D-glucitol 2-nitrate 5-methanesulphonate.

This free hydroxyl group is esterified with nitric acid, nitrating acid or with a mixture of nitric acid and glacial acetic acid/acetic anhydride in the presence of urea at a reduced temperature, preferably at -20° to 0° C., to give the corresponding aminodesoxy-1.4;3.6-dianhydrohexitol mononitrate, whereby, instead of the aminodesoxy-1.4;3.6-dianhydrohexitol in the form of the free base, a suitable acid-addition salt, for example the corresponding salt of methanesulphonic acid, nitric acid or sulphuric acid, can also be used for the esterification.

Nitrosation agent(s), contained as by-products in nitrated aromatic compounds after nitration with nitric acid or nitration acid, are removed by a water treatment, wherein the water is distilled off at least partially in vapor form, advantageously under reduced pressure.

The further working up of the reactive intermediate products according to the invention to give the end products, thus the corresponding mononitrates, takes place in such a manner that the free hydroxyl group of the corresponding possibly N-substituted aminodesoxy-1.4;3.6-dianhydrohexitol (R3 =H), which is possibly previously obtained by alkaline hydrolysis of the corresponding mesylate or tosylate (R3 =methanesulphonyl, toluenesulphonyl), is esterified with nitric acid, nitrating acid or with a mixture of nitric acid and glacial acetic acid/acetic anhydride, possibly in the presence of urea, to give the corresponding aminodesoxy-1.4;3.6-dianhydrohexitol nitrate.

This nitration acid is used in a quantity such that at least 0.1 mole, preferably from 0.1 to 2.1 moles, and most preferably from 0.2 to 1.2 moles of nitric acid are available for each mole of dinitro compound. When used in such quantities, at least 0.1, preferably from 0.1 to 1 more nitro group (on a statistical average) is introduced into the dinitro compound during nitration, thereby increasing the NO2 -functionality to more than 2, preferably from 2.1 to 3, and most preferably from 2.2 to 2.7.

The nitration reaction may be carried out in the presence of a suitable solvent, such as methylene chloride, using "nitration acid", i.e., a mixture of concentrated sulfuric acid and nitric acid (preferably highly concentrated, approximately 98% nitric acid).

The temperature is then adjusted to the reaction temperaure and the nitrating acid, which is in an amount about 5% above the stoichiometric amount necessary for mononitration of the reaction substrates employed, is then run in, while keeping the temperature in the same range.

Other electrophilic reagents which can be used are sulphuryl chloride, phosphorus oxychloride/dimethylformamide, nitrating acid and other substances customarily used for electrophilic substitutions.

Water can be incorporated into nitrocellulose via centrifuge technology, nitrating acid from the nitrocellulose preparation being displaced by water in a centrifuge by spraying, on water (c.f. K. Fabel, Nitrocellulose, p. 100 et seq. and US-PS-3 063 981).