DE151134C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

As from the treatises by H ilk enkamp (Ann. 95, 92), Carius (annual report on el. Fortschr. D. Chemistry 1861, 634) and R. Smit. (Ber. D. The former Ges. 8, 1442)

.5 shows, the nitrobenzene suffers from prolonged boiling with absolute alcohol and neutral ammonium sulfite with the addition of ammonium carbonate a conversion into other substances. Regarding the conversion products, which in the former Treatises are insufficiently characterized, it is stated by Smit that he Phenylsulfanilsaüres received ammonium, which according to the formula established by him would be identical to phenylsulfamic acid ammonium. He referred to the yield as small amount. How insignificant it is is best seen from the fact that it is an end sees itself compelled to an analysis, the products of three differently directed To mix operations from 60 g of nitrobenzene each.

It is obvious that in this process the main reaction is in another Senses proceeds and the formation of phenylsulfanilic acid ammonium, its identity with the phenylsulfamic acid salt, by the way

., not proven, just a side reaction represents. Aveniger can speak of a technically feasible process, than the absolute alcohol and the neutral ammonium sulfite, which is technically hardly accessible their application for the preparation of intermediate products, which by their nature are only low are allowed to appear in the price.

On the other hand, it can be derived from such information that it relates to absolute alcohol. Solutions and relate neutral ammonium sulfite, no conclusion on the possibility and the course of similar Derive reactions in aqueous solution, as from a comparison of the information in / Patent 92082 with the results the Piria reaction (Ann. 78, 32) emerges.

In fact, the information already available regarding the effect differs from Sulphites on nitrobenzene and nitrotoluene in aqueous liquid of those mentioned at the beginning Results.

R. Nietzki states in patent specification 86097, “Nitrobenzene is different from alkali metal sulfite not attacked «; J. Walter also reports in the patent specification 109487, “There is p-nitrotoluene (with alkali sulfites) not the sulfonic acid, but p-toluidine «. As for the rest Nothing is known of homologues.

In view of this information and the fact that the reduction in nitrohydrocarbons has dealt with researchers to a great extent in recent years, was a different and commercially viable result not to be expected.

The surprising observation has now been made that nitrobenzene and his Homologues quickly and smoothly reduced by the action of aqueous solutions of acidic sulphites with predominantly sulfamine

acid salts are formed and amidosulfonic acids are obtained in minor amounts can. The amount of sulfamic acid salts obtained increases with the number of in the Benzene ring entering alkyl groups and is z. B. at a techn. Nitroxylene against 95 percent of the theory; Increase alkyls occurring in the position parallel to the nitro group the yield of sulfamic acid is slightly more than the corresponding substituents in the ortho position.

This behavior is different from the behavior

those substitution products of the nitro '

. benzene, which so far have been shown to be reducible by sulfites, completely from, insofar as in the latter cases only amidosulfonic acids are obtained (Patent 86097 and 109487, also 123115). The formation of sulfamic acids Salts from alkyl substitution products of nitrobenzene were therefore to a high degree unlikely and unpredictable. While also in the patent 86097 is stated, “This reaction takes place most easily with the use of neutral Alkali sulphite «, this reagent fails almost completely for the preparation of sulphamic acids.

In fact, nitrobenzene will, accordingly

the information from Nietzki, from neutral Sulfites attacked only very badly; but there is no trace of sulfamic acid and the process goes in a completely different direction; they are even more resilient Nitrotoluenes against neutral sulfites (at least at the boiling point in an open vessel); the end 14 parts of nitrotoluene could after 12 hours Boil with 3 molecules of neutral sulfite to get 13 parts back unchanged will. Traces of sulfamic acid are then formed, while J. Walter (loc. Cit. whether with neutral or acid sulfites is not specified) have received toluidine want. From all of this, however, it emerges anew that not only the possibility of reduction of nitrobenzene etc. is subject to certain conditions that cannot be regarded as given in advance, but that the products of such sulphite reactions are also very different can, so that also know in advance the direction of any reaction that may occur nothing can be determined.

As a substitute for those that come into consideration for the preparation of sulfamic acids Acid sulphites can be used as mixtures of neutral sulphites with weak acids, such as Acetic acid, or the sulphites of alkaline earths and other metals such as magnesium, Zinc, manganese, etc., with simultaneous passage of sulfur dioxide. '

The use of lime (or the resulting calcium sulfite) and sulfur dioxide , probably with the cheapest materials that are technically used a very cheap production of sulfamic acids respectively. of their conversion products.

When sodium bisulnt is used, the reaction proceeds in the sense of the following equations :

i. Ar - NO ₂ + 3 NaHSO ₃ == Ar - N ( ¹ Zr, "+ 2 JVa H SO ₁

N / A

2.2 Na H SO ₄ + 2 Na H _{5O 3} = .2 JViT ₂ SO ₄ + 2 H ₂ O + 2 5O ₂ . Ar = C ₆ H ₅ etc.

If only the amount of bisulfite corresponding to equation 1 is used, the result is some sulfur due to the action of the acid sulphate on the sulphamic acid salt. Amine. The amount of bisulfite corresponding to equation 2 can be replaced by 1 molecule neutral sulphite or acetate.

Mixtures of acidic and neutral sulphites should react according to the following equations

Ar-

Ar - N0. ₂ + 3 NaHSO., = 2NaH SO

^N \ S0 ₃ Na

2. 2 Na HSO _4. + 2Na ₂ SO ₃ =

2 Na ₂ SO ₄ + 2 Na H.SO ₃ .

This results from addition

3. Ar-NO ₂ + NaHSO _n

Ar

/H

2Na ₂ SO ₃ =

In reality, however, that of the equation is sufficient 3 insufficient amount of bisulfite to carry out the reaction.

Of course, you can also use pressure, in a closed vessel or under Adding alcohol to work. But these are only complications that do not result in any Result in advantages.

The reaction proceeds faster in dilute than in concentrated bisulfite solution, and it is also delayed by adding other salts. Nitrobenzene is z. B. reduced from 10 percent bisulfite solution when boiling in about ³ J ₄ hours, with 40 percent bisulfite solution but only in about 10 hours. The reduction products are the same in both cases. The nitrotoluenes are even more difficult to attack by concentrated bisulfite solution. Perhaps for this reason the reaction has so far eluded observation.

The sodium salts of sulfamic acids can be made from sufficiently concentrated, best

Separate weakly acidic solution with common salt almost quantitatively.

Sulphamic acids of the benzene hydrocarbons have so far been obtained in an undoubted manner by processes (W _1. Traube, Ber. Dd former Ges. 23, 1656; Paal and Jänicke, ibid. 28, 3162; Bamberger and. Hindermann, ibid. 30, 654; Michaelis and Petou, ibid. 31, 984; Junghahn, ibid. 31, 1234), who rule out the fact that these substances cannot easily be converted into ortho- and para-amido sulfonic acids and into aromatic amines for the technical production of these body classes.

The made possible by the method described, very cheap production of the sulfamic acid salts thus fills a previously existing gap.

The sulfamic acids of the alkyl-substituted benzenes formed in high yield should be used for the production of aromatic amines.

But they should all be used mainly for the preparation of sulfonic acids. The rearrangement of the sulfamic acids into the sulfonic acids takes place quickly and smoothly in the most varied of ways, be it by heating the salts by themselves or with the addition of Y ₂ molecules or less concentrated sulfuric acid or other concentrated acids with or without the passage of a gas stream.

The known transferability of the SuIf-

It crystallize out 95 percent alcohol Water resp. Saline solution Sodium salt of phenylsulfamine
40 ^acid Fine parallelepiped
Crystals next to microcrystalline
powder Microcrystalline excretion Sodium salt of, o-tolylsulfamine
acid Leaflets Diamond-shaped crystals 45 sodium salt of p-tolylsulfamine
acid Crystals of the shape, wider
, Lancets Well-formed rhombuses alongside
microcrystalline aggregates
(the latter from the cooled solution) Sodium salt of xylylsulfamic acid
from techn. Nitroxylene Well-trained needles Crooked needles Sodium salt of xylylsulfamic acid
1-3-4 the same the same

amino acids into the otherwise more difficult to access orthosulfonic acids of the non-para-substituted amines (Bamberger and Kunz, Ber. dd. Ges. 30, 2274) have already been mentioned. _;

The sulfamic acids which are alkyl-substituted in the para position give only orthoamidosulfonic acids during the rearrangement. The latter can also from the corresponding nitro hydrocarbons directly next to the sulfamic acids in minor amount can be obtained.

In this case they are not the rearrangement products of the latter, because their quantity increases do not interfere with prolonged boiling or the passage of sulfur dioxide. ,She are apparently not as such in the reducing liquid, but presumably as They contain sulfamine sulfonic acids, because their alkali salts cannot be left out with salt precipitate after the reduction liquid made alkaline, but after its previous decomposition with mineral acid (after removal of the sulphamic acid produced in this process arom. amines).

Some of the properties of the sulfamic acid salts are known (loc. Cit.). The sodium salts of the sulfamic acids can all be easily recrystallized from 95 percent alcohol and in this way the salts of phenyl and o-tolylsulfamic acid, which are very readily soluble in water, can also be obtained free of common salt. .

The sulphamic acids are quite resistant to dilute mineral acids in the cold; in the heat they invariably decompose with the formation of amine salts. The sulfamic acids, which are sparingly soluble in dilute hydrochloric acid and which correspond to p-toluidine and xylidines, can be separated from the aqueous solution of the salts by adding sufficient hydrochloric acid. The melting point of a xylylsulfamic acid from techn. Nitroxylene was found starting at 15 5 ⁰ against 200 ⁰ ; that of 1 · 3 · 4-xylylsulfamic acid against 200 ⁰ . It depends very much on the type of heating, if you warm up slowly you will notice significant sintering beforehand. ·: ··

Claims (1)

Example I. 14 parts of p-nitrotoluene are percent with 130 parts of 40 bisulfite solution (or 100 parts of bisulfite solution, was about '/ ₃ to' / neutralized ₂ before the.) Or crystallized with 75 parts of neutr. Sulphite with addition of 45 parts of 40 percent acetic acid and 250 to 300 parts of water on the reflux condenser until boiling (or only to 80 to 90 ⁰ ) heated. The triggering takes place at the boiling point within approximately one hour. You can then precipitate the p-tolylsulfamic acid sodium bicarbonate directly with table salt, but it is more expedient to evaporate a little beforehand and to let most of the Glauber's salt crystallize out and only then to salt it out. The sulfamic acid salt which has separated out is filtered off with suction and dried at water bath temperature. The yield is 80 percent of theory. To obtain the incidentally available ι ·. 4 · 5 -toluene amido sulfonic acid is added the mother liquor of the sulfamic acid salt with excess mineral acid and heated to simmer. It is then supersaturated with soda and any p-toluidine that appears is removed If the water vapor flows, the sodium salt of the acid crystallizes out on cooling. In the above example, the p-nitrotoluene can be replaced by equivalent amounts of Nitrobenzene, o-nitrotoluene, nitroxylenes or Mingle these bodies. The reduction of the techn. Nitroxylene runs more slowly and takes about 5 to 6 hours. The process for obtaining the sulfamic acid salts both "and" the sulphonic acids formed in the process remain, for the rest the same. -., '... _. Example. II. 12.5 parts of Nitro.be.nzol are mixed with 36 parts of calcium sulfite and 20.0 parts of water or the equivalent. A lot of milk of lime is heated to the boil (or only to 70 to 80 °) while passing sulfur dioxide through it, until no more nitrobenzene is noticeable. When using a finely powdered calcium sulphite and the corresponding addition of sulfur dioxide, the reaction at the boiling point is approximately ^:! / ₄ hours finished. The plaster of paris is filtered off and the phenylsulphamic acid is salted out either directly or after the solution has been previously concentrated. Ρλ τ ε ν τ - A ν s ρ r υ c η: Process for the preparation of salts of the sulfamic acids of benzene as well as its homologues, characterized in that the corresponding mononitro derivatives in aqueous solution lets acidic sulphites act with or without the addition of neutral sulphites.