DE1205963B - Process for the preparation of the monosulfonic acid anhydrides from alkylated halogenated aromatic compounds - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN mSWWs PATENT OFFICE

EDITORIAL

Int. α .:

C07c

German class: 12 ο -23/01

Number:
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A39251IVb / 12o
17th January 1962
December 2, 1965

The present invention relates to a process for the preparation of the monosulfonic anhydrides of alkylated haloaromatics by sulfonating the latter with sulfur trioxide, which is characterized is that the sulfonation is carried out in the presence of nitromethane.

There are sulfonation processes in the presence of organic solvents such as nitrobenzene and Chlorinated hydrocarbons are known, but sulfonic acids are obtained. Furthermore is at Sulphonation processes involve the use of agents containing nitro groups as reactants known.

It is also used in sulfonating halogen-substituted aromatic hydrocarbons known, the halogenated hydrocarbon at room temperature to a 10 to 20 ache amount of oleum to add. The sulfonation is achieved by allowing the mixture for some time, normally 24 hours or more. This generally forms the sulfonic acid, which does not precipitate from the reaction mixture and which are difficult to isolate and convert to the anhydride is. In some cases, however, sulfonic anhydride is obtained directly. To isolate this Anhydrides, the reaction mixture is poured onto ice after the sulfonation process has ended The anhydride is separated off by filtration and washed with ice water, acetone and ether. But also in this case the process is flawed because the anhydride is often relatively highly contaminated and must be subjected to further cleaning processes.

It is the aim of the present invention to provide a method of the type mentioned which does it makes it possible to work in a particularly simple manner and without unnecessarily large amounts of liquid must, usually with good yield and a minimum of purification operations, the desired ones Produce sulfonic anhydrides directly in a relatively high yield.

According to the invention, this aim is achieved in that the sulfonation is carried out in the presence of nitromethane performs.

It has been shown that nitromethane easily forms stable solutions with sulfur trioxide. The solution of sulfur trioxide in nitromethane can be kept at a temperature of ⁰ ° C. for at least four hours. Nitromethane also has good dissolving power for water. It is also a good solvent for the halogenated aromatic hydrocarbons in question, where processes for the preparation of the monosulfonic anhydrides of alkylated halogenated aromatic compounds

Applicant:

Atomic Energy Commission, Copenhagen

Representative:

Dipl.-Ing. R. Müller-Borner

and Dipl.-Ing. H.-H. Wey, patent attorneys,

Berlin 33, Podbielskiallee 68

Named as inventor:

Niels Hesselbjerg Christensen,

Himmelev, Roskilde (Denmark)

Claimed priority:

Denmark, January 26, 1961 (350)

against them only little dissolving power with respect to the sulfonic acid anhydrides formed in the reaction demonstrate. The reaction is carried out in a medium which is not very viscous and in which the formation of sulfonic acid is suppressed. In addition, the lack of or poor dissolving power of the nitromethane compared to the formed Sulphonic anhydride causes this to gradually crystallize out of the reaction mixture as a well-crystallized one and therefore relatively pure precipitation is excreted. This deposition is beneficial on the other hand, also the course of the reaction.

Since the desired sulfonic acid anhydrides can be obtained directly and relatively pure with the method according to the invention, the method is particularly suitable when one wants to obtain technically pure sulfonic acid anhydrides for analytical and synthetic purposes. The method is also useful in the microsynthesis field, e.g. B. for the production of compounds containing radioactive isotopes. This provides a process by which ^{sulfonic anhydrides containing 35} S can be produced quickly and with little loss of radioactive sulfur. The ^{sulfonic acid anhydrides containing 35} S are used as trace substances in radiochemistry; z. B. p-iodobenzenesulfonic acid anhydride containing ³⁶ S is used for the detection of small amounts of steroid hormones.

This compound has hitherto been obtained by sulfonating acetanilide with ^{oleum containing 38} S in counter-

509 740/427

wart prepared from acetic acid, whereby ^{p-acetylaminobenzenesulfonic acid containing 35} S is obtained, which was converted into pure p-iodobenzenesulfonic acid anhydride via a series of compounds (p-aminobenzenesulfonic acid, p-iodobenzenesulfonic acid, p-iodobenzenesulfonic acid chloride, p-iodobenzenesulfonic acid).

The invention is explained in more detail below with reference to the following examples.

IO

example 1
p-iodobenzenesulfonic anhydride

500 mg of iodobenzene are dissolved in about 0.5 cm ^{3 of} nitromethane. The solution is cooled in ice water, and 1 cm ^{3 of} a cooled solution of sulfur trioxide in nitromethane which contains 340 mg SO ₃ / cm ^{3 is} added. The mixture is shaken in ice water with further cooling, ao-p-iodobenzenesulfonic anhydride precipitating practically instantaneously. After standing at 0 ° C. for 15 minutes, it is decanted off and the precipitate is washed with about 3 cm ^{3 of} nitromethane and then twice with 3 cm ^{3 of} ether. It is dried over sodium and finally with pentane. The pentane is then driven off with moderate heating by means of a stream of nitrogen which has previously been dried with phosphorus pentoxide. A yield of about 79% is obtained, calculated on iodobenzene. The melting point of the product is 220 to 221 ° C. after repeated recrystallization from nitromethane.

In the same manner using a molar ratio of SO ₃ to hydrocarbon such as 1.7: 1, bromobenzene, m-chlorotoluene, p-chloro-toluene, m-bromotoluene, 1-chloronaphthalene, 1-bromonaphthalene, 2-bromonaphthalene , Chlorobenzene, asymmetrical trichlorobenzene and o-chlorotoluene sulfonated.

In each case, the monosulfonic anhydride of the compound used was obtained. the The yield, the equivalent weight and the melting point of the compounds obtained are based on the following Lineup:

Sulphonated «compound monosulphonic anhydride

Equivalent weight calculated Melting point today found 228 ⁰ C 60 232 198 178.5 to 182 70 195 198 149 to 150 90 199 242 210 to 211 60 237 234 179.5 to 180.5 50 246 278 218.5 to 219 60 285 278 217 to 218 20th 284 184 227 to 229 35 190 253 130 to 141 14th 263 198 not determined 30th 192 148 to 151

Bromobenzene

m-chlorotoluene

p-chlorotoluene

m-bromotoluene

1-chloronaphthalene

1-bromonaphthalene

2-bromonaphthalene

Chlorobenzene

unsymmetrical trichlorobenzene
o-chlorotoluene

Example 2
³⁵ S containing p-iodobenzenesulfonic anhydride

40

5 cm ^{3 of} an aqueous solution of ^{sulfate ions containing 35} S and having a specific activity of about 600 mCurie were brought to a total content of 10 mg SO ₃ by adding sulfuric acid.

The resulting active solution was placed in a 10 cm ³ sample tube with a ground neck. The sample tube was heated ^{to 100 ° C. in a bath;} a slow stream of nitrogen was passed over the surface of the liquid in the sample tube. After the liquid had been concentrated in this way, the bath temperature was ^{increased to 120 °} C. for about 5 minutes until the inner walls of the tube were completely dry. The tube was then closed and placed in ice water.

From a previously prepared solution of sulfur trioxide in nitromethane, which contained 340 mg SO ₃ / cm ³ , 1 cm ^{3 was introduced} into the sample tube with the ³⁵ S-containing material by means of a pipette and the contents were mixed. The tube was then placed back into ice water and, as described in Example 1, 350 mg of iodobenzene, which was dissolved in about 0.5 cm ^{3 of} nitromethane, was added. The reaction mixture was treated and the precipitate was separated off in the same manner as described in Example 1. The precipitate of ^{p-iodobenzenesulfonic acid anhydride containing 35} S thus obtained was purified by repeated recrystallization from nitromethane. The yield of purified ³⁵ S containing p-iodobenzenesulfonic anhydride was about 70% calculated on the iodobenzene. The melting point was 221 to 222 ° C. and the specific activity was about 300 mC / g, corresponding to an activity yield of 25%.

No protection is sought for the production of the ³⁵ S-labeled sulfonant.

Claims (2)

Patent claims: 1. Process for the preparation of the monosulfonic anhydrides of alkylated haloaromatics by sulfonating the latter with sulfur trioxide, characterized in that the Performs sulfonation in the presence of nitromethane. 2. The method according to claim 1, characterized in that one ^{uses a partially marked by 35} S sulfur trioxide. Considered publications: Houben-Weyl, Methods of Organic Chemistry, Vol. IX [1955], p. 502;
Chem. Zentralblatt, 1956, p. 13 091. 509 740/427 11.65 © Bundesdruckerei Berlin