Übersetzung für "Anhydrous ammonia" in Deutsch

Particular preference is given to using anhydrous ammonia or anhydrous amines.

Anhydrous ammonia or anhydrous amines are particularly preferably used.

Anhydrous ammonia or aqueous or aqueous-organic ammonia solutions can be used for the reaction according to the invention.

The anhydrous ammonia vapor is liquefied in a condenser 8 by a water-cooled coil 9.

In water free operation there can be used alcoholates, especially sodium methylate or sodium ethylate or anhydrous ammonia.

Potassium azide (containing 2%-6% potassium nitrate) can be applied in anhydrous ammonia.

The bases most commonly used in the olefin synthesis are aqueous or anhydrous alkali metal hydroxides and alkaline earth metal hydroxides, and aqueous or anhydrous ammonia, the alkali metal carbonates and alkaline earth metal carbonates, preferably sodium carbonate and potassium carbonate, and basic magnesium carbonate and calcium carbonate.

300 ml (12 mols) of anhydrous ammonia are pumped into the autoclave at this temperature, the pressure increasing to 70 bars.

Anhydrous ammonia is introduced into a solution of 2.0 g (5.9 mmol) "GPAA" methyl ester (formula (3), the product of Example 2, supra), in 16 ml methanol, at 0° C., until saturation with ammonia occurs.

The suspension obtained in this manner is transferred into a 5 l agitated autoclave, combined with 1250 ml methanol and 0.45 l anhydrous ammonia and hydrogenated in the presence of 35 g Raney nickel and 12.5 g nickel chloride hexahydrate at 110° C. and 100 bars hydrogen pressure.

To avoid the formation of undesirable quantities of water, the reaction mixture is neutralized by addition to the medium of gaseous ammonia, anhydrous amines or alkali alcoholates, such as the glycolic alkali alcoholates or alkali metals.

It has now been found that 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNS) and salts thereof can surprisingly be prepared in high yields without the abovementioned disadvantages by oxidation of 4-nitrotoluene2-sulfonic acid with an oxidizing agent by performing the oxidation in liquid, anhydrous ammonia, in an alkyl derivative thereof in the presence or absence of water and/or mixtures of these solvents in one another.

Accordingly, this application provides a process for the preparation of 4,4'-dinitrostilbene-2,2'-disulfonic acid and salts thereof of the formula ##STR1## in which M is hydrogen, an alkali metal cation or an ammonium cation, by oxidation of 4-nitrotoluene-2-sulfonic acid or salts thereof with an oxidizing agent, which comprises performing the oxidation in liquid, anhydrous ammonia, in an alkyl derivative thereof in the absence or presence of water and/or mixtures of these solvents in one another and in the presence of strong bases and in the absence or presence of catalysts.

Liquid, anhydrous ammonia, an alkyl derivative thereof in the absence or presence of water and/or mixtures of these solvents in one another, which are used as reaction solvents in the present process according to the invention, are to be understood as meaning in particular the following solvents or combinations:

However, it is also possible to operate under water free (anhydrous) conditions if one starts from the liquid esters and employs anhydrous ammonia as the HCl-acceptor.

Also used for producing the copolymers employed for the coating is preferably maleic anhydride, it being then possible to convert the anhydride groups contained in the copolymer, depending on the method to be used to apply the coating to the reinforcing fibres, into monosodium, monopotassium, monocalcium or monoammonium salts, amides, carboxyl groups or half-esters, the degree of esterification being able to extend from 1 to 100%, by adding to the copolymers containing the anhydride groups, for example in the benzolic suspension, anhydrous ammonia or sodium hydroxide, potassium hydroxide or calcium hydroxide.

The residue was chromatographed on silica gel with a solution of anhydrous ammonia in ether, the medium pressure flash chromatography method being used and the pressure being produced with nitrogen gas.