US1102827A - Process of producing sulfonic acids. - Google Patents

Description

- A. VAGT. PROCESS 0F PBODUGING SULFONIG ACIDS.

APPLIUATION FILED DB0. 6, 1911.

1,102,827. Patented July 7, 1914.

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NEAR COLOGNE, GERMANY, ASSIGNOR T0 FARBEN- FABRIKEN VORM. FRIEDR. BAYER & C0., 0F ELBERFELD, GERMANY, A fJOIRlPOIRA-v TIGN GERMANY.

PROCESS OF PRODUCING SIULFONIC ACIDS.

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To all whom. 'it may concern Be it known that l, AUGUST VAGT, doctor chemist, citizen of the German Empire, residing at Leverkusen, near Cologne, Germany, have-invented newand useful Improvements in Processes of Producing Sult'onic Acids., of which the following is a specification.

My invention relates to a new and valuable process of splitting off sulfonic groups from aioiiiatic sulfoiiie acids which process consists in bringing the said organic compounds in contact with an amalgam of an alkali-forining metal, e. g., alkaline or earth alkaline metal, that has been produced by electrolysis. 'llie reaction is carried out. 1n a separate chamber being in communication with the electrolyzer by a layer of mercury,l

the latter being kept in circulation.

ln the accompanying drawings which show one Jorm ot' apparatus in which vthe present process can be carried out the chamber (L has in its bottom a layer of mercury into which the cylinder I) dips, the mercury thus forming a seal. The anode c liquid contained in the cylinder Z) and the other connection is obtained by means of the wire ci which extends into the layer of zmercury. A. stirrcr f is provided for the liquid g in the outer chamber. n

1n order 'to illustrateJ my invention the following example is given, the parts being by Weight-0n the bottom of a chamber is a layer of mercury of about 1 to 2 cent1- nieters depth. lnto the mercury the cylinder b dips. ln this cylinder caustic soda lye is decomposed by an electric current which is introduced by the anode c and the isolated thread d. The stirrer f keeps in motion'tlie mercury which absorbs the sodium in Z) and carries the amalgam into g where the reduction takes place. 250 parts ot'- l-naphthylamin-3-8-disulfonic acid (disodium salt) are dissolved in 2000 parts of water and poured into the chamber a. The caustic soda lye in the chamber b is a 25 per cent. lye. 0

The electrolysis is carrled out with an electric current of 10-20 amperes on 100 square centimeters While it is stirred. When in g the quantity of sodium sulfite produced by the sultonic group being split ofi' show s that one group is split oli', the solution 1s Specification. of Letters Patent. Application :tiled December Patented July '7, jlill. semi no. 664,204.

acidulated, boiled and the 1-naplithylamin- --sulfonic acid is filtered off. ln the same ii'ay the following acids can be produced: From anilin--disulfonic acid the anilin-3- inouosulfoiiic acid, from l-naphthylainiiil-.S-disulfonic acid the l-naphthylamin- -t-'sult'onic acid, from Q-naphtliylamin-ldisulfonic acid the Q-naphtliylainin-S-sultonic acid, from Q-Iiaplithylamin5.7disul foiiic acid the Q-naphthylamin-7sulfonic acid, from 1iiaphthylamin-3.51;7-ti'isulfonic acid the 1 naplithylamin 3.7 disulfoiiic acid, from 1naphthylamin-QA-trisulfonic acid the l-naphthylainin-2.(S-disul'tonic acid, Jr'roin 1-naphthylainiii-2.5.7-ti'isulfonic acid the l-naplithylainin2.7disulfonic acid, lroni 1-naphthol3.8disulfonic acid the jl-naphtliol-sulfonic acid, from l-naplitliol2.-t.8 ti'isulfonic acid the 'l-naphthol-2.4disulfonic acid and from 2naphtliol-3.(3.8-trisulfonic acid the Q-naphtliol-l-disulfonic acid.

l claiin:- 1. The. process of Splitting 0E sulfoni groups from aromatic sulfonic acids which comprises continuously producing an amalgam of an alkali-forming metal and .circulating such freshly prepared amalgam into contact with the aromatic sulfonic acids.

2. The process of splitting ofi' sulfonic groups from aromatic sulfonic acids whichy comprises continuously producing` sodium amalgam and circulating such freshly prepared amalgam into contact with the aromatic sulfonic acids. i

3. '.lhe process of splitting off sultonic.v

groups from aromatic sulfonic acids which comprises producing an amalgam of an alkali-forming metal electrolytically, circulatingsuch electrolytically prepared amalgam in contact with the aromatic sulfonic acids, and continuing the electrolytic production of the'am'algam and the reduction of the sulfonic acids by circulating the same amalgam alternately into reactive relation with the electrolytic bath and with'the acidl 4. The process of producing aromatic sulfonic acids from aromatic poly-sulfonic acids containingr a larger number of sulfonic acid groups which comprises circulating in Contact with such acids electrolytically prepared amalgam of an alkali-forming metal in `,which amalgam the alkaliforming metal is replaced vcontinuously as the re-action progresses.

he process of splitting ofi' sulfonic groups from aromatic poly-sulfonic acids and of producing aromatic sulfonic acids containing a smaller number of sulfonic acid groups which comprises producing an amalgam of an alkali-forming metal electrolytically and circulating such freshly prepared 'amalgam into contact-With the aro.- matic. oly-sulfonic acid continuously7 the alkaliorming metal of the amalgam being replaced contlnuously in the amalgam and the strength'of the amalgam being thereby maintained approximately constant.

4 6. The process of splitting off sulfonic groups from aromatic poly-'sulfonic acids and of producing aromatic sulfonic acids containing a smaller number of sulfonic groups which comprises producing sodium amalgam electrolytically and clrculating such freshly prepared amalgam into contact with .the aromatic po1y-sulfonic acid continuously, the sodium of the amalgam being replaced continuously in the amalgam and the strength of the amalgam being thereby maintained v approximately constant.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses. y y

AUGUST VAGT. [L. 5.] Witnesses: v

HnmN NUFER, A. N UFER.

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