CH164737A

CH164737A - Process for the preparation of a halogen derivative of 2-aminonaphthalene-1-sulfonic acid.

Info

Publication number: CH164737A
Authority: CH
Inventors: Aktiengesellsc Farbenindustrie
Original assignee: Ig Farbenindustrie Ag
Priority date: 1931-06-15
Filing date: 1932-06-10
Publication date: 1933-10-15

Description

  

      Verfahren    zur     Darstellung        eines        Halogenderivates    der     2-Aminonaphtaliii-          1-sulfosäure.            Clegenstand    des vorliegenden Zusatz  patentes ist ein Verfahren zur Darstellung  eines Halogenderivates der     2-Aminonaph-          thalin-l-sulfosäure,    welches dadurch gekenn  zeichnet ist, dass man     7-chlor-2-oxynaph-          thalin-l-sulfosaures    Natrium mit Ammoniak       iii    Gegenwart eines     8ulfites    in einem ge  schlossenen Gefäss längere Zeit erhitzt.

           Beispiel:     156 Gewichtsteile technisches     7-chlor-2-          oxynaphthalin-l-sulfosaures    Natrium, wel  che     140    Gewichtsteile     100%igem    Produkt  entsprechen, werden mit 200 Gewichtsteilen       25%igem    wässerigem Ammoniak, 60 Ge  wichtsteilen     Ammoniumsulfit    und 100 Ge  wichtsteilen Wasser im     geschlossenen    Gefäss       etwa    30 Stunden auf     etwa   <B>150'</B> erhitzt.

   Das  Reaktionsprodukt wird mit Wasser     auf-          ,genommen,    das Ammoniak     abdestilliert,    die       #$ung    eventuell von Verunreinigungen fil-         triert    und aus dem Filtrat das neue Produkt  durch Zusatz von Kochsalz abgeschieden.       Das        Natriumsalz    der so erhaltenen     7-Chlor-          2-aminonaphthalin-l-sulfosäure    löst sich in  kaltem Wasser im Verhältnis 1 :20. Aus  sehr viel Alkohol kristallisiert es in weissen,  glänzenden Blättchen.

   Aus der wässerigen  Lösung des     Natriumsalzes    fällt auf Zusatz  von     Mineralsäure    die freie Säure in weissen  Flocken aus, die sich unter dem Mikroskop.  als dünne Nadeln     zeigen.    Sie schmilzt bei  sehr hoher Temperatur unter Zersetzung, ist  in Wasser schwer löslich und gibt eine gelb  liche,     schwerlösliche        Diazoverbindung.  



      Process for the preparation of a halogen derivative of 2-aminonaphthalene-1-sulfonic acid. The status of the present additional patent is a process for the preparation of a halogen derivative of 2-aminonaphthalene-1-sulfonic acid, which is characterized in that 7-chloro-2-oxynaphthalene-1-sulfonic acid is sodium with ammonia in the presence of a 8ulfites heated in a closed vessel for a long time.

           Example: 156 parts by weight of technical 7-chloro-2-oxynaphthalene-l-sulphonic acid sodium, which correspond to 140 parts by weight of 100% product, are mixed with 200 parts by weight of 25% aqueous ammonia, 60 parts by weight of ammonium sulphite and 100 parts by weight of water in a closed vessel Heated to about <B> 150 '</B> for about 30 hours.

   The reaction product is taken up with water, the ammonia is distilled off, the impurities are possibly filtered out and the new product is separated from the filtrate by adding common salt. The sodium salt of the 7-chloro-2-aminonaphthalene-1-sulfonic acid thus obtained dissolves in cold water in a ratio of 1:20. From a great deal of alcohol it crystallizes in white, shiny flakes.

   From the aqueous solution of the sodium salt, the addition of mineral acid precipitates the free acid in white flakes, which can be seen under the microscope. show as thin needles. It melts at a very high temperature with decomposition, is sparingly soluble in water and gives a yellowish, sparingly soluble diazo compound.

Claims

PATENT CLAIM: Process for the preparation of a halogen derivative of 2 - aminonaphthalene-l-sulfonic acid, characterized in that 7 - chlorine - 2 - oxynaphthalene-l-sulfonic acid sodium with ammonia in the presence of a sulfite in a closed vessel for a longer time :heated. The sodium salt of the 7-chloro-2-aminonaphthalene-1-sulfonic acid thus obtained dissolves in cold water in a ratio of 1:20.

From a great deal of alcohol it crystallizes in white, shiny flakes. From the aqueous solution of the sodium salt, the addition of mineral acid precipitates the free acid in white flakes, which appear as thin needles under the microscope. It melts at a very high temperature with decomposition, is sparingly soluble in water and gives a yellowish, sparingly soluble diazo compound. SUBCLAIMS: 1.

Method according to claim, characterized in that the ammonia is used as aqueous ammonia. 2. The method according to claim, characterized in that ammonium sulfite is used as the sulfite. Process according to patent claim, characterized in that the reaction is effected by heating for about 30 hours at a temperature of about 150 C in a closed vessel.