CH209578A - Process for the preparation of a quinhydron. - Google Patents

Description

  

  <B> Additional patent </B> to main patent no. <B> 207513. </B> Process for the production of a quinhydron. It is generally known that benzoquinone and various other simply composed quinones can be converted into quinhydrons.

   These quinhydrons are mostly found as molecular compounds between the quinone and the corresponding hydroquinone, i.e. H. the compound in which both keto groups of the quinone are reduced to hydroxyl groups.

   These quinhydrones could, for example, by reacting quinones with hydroquinones, in some cases also by partial reduction of the quinones or partial oxidation of the hydroquinones, ie. H. can generally be obtained by partially changing the oxidation state of the component contained in the quinhydrons.

   It can always be assumed here that one component is formed as an intermediate from the other and then reacts with it.



  The view has also been taken that quinhydrones are not molecular compounds, but rather intermediate stages present in monomolecular form between the compound containing at least two keto groups and the compound in which the geto groups up to hydroxyl groups are reduced.

       Irrespective of the particular way quinhydrons are interpreted, the ways in which they can be produced are always the same.



  It has now been found @that a new and valuable quinhydrone from. the corre sponding quinone can be produced if you choose flavanthrone as the quinone and the leuco compound of the dye mentioned can act on the dye.



  The new quinhydron is a brown, sandy powder that dissolves in concentrated sulfuric acid with an olive green color and dyes cotton from a dark blue-violet vat in yellow tones. It is very easy to shred.



  The effect of the luco compound of the flavanthrone on the flavanthrone can in the presence of organic solutions or. Diluents, such as, for example, alcohol, are carried out, but expediently in an aqueous medium at a lower or preferably elevated temperature, for example at about 30-80 ° C., advantageously in an alkaline medium.



       Example: 21 parts of flavanthrone (Schultz, dyestuff tables, 7th edition, No. 1241) are suspended in a mixture of 700 parts of alcohol, 150 parts of water and 50 parts of 10% sodium hydroxide solution and, in the presence of a nickel catalyst, for so long with hydrogen shaken until the uptake per 1 mole of flavanthrone is 1 mole of hydrogen.

   After the catalyst has been removed by filtration at 35-40 'under hydrogen, a dye paste prepared by grinding 10 parts of flavanthrone with 100 parts of alcohol is added to the deep violet-blue solution of the dihydroflavanthrone, whereupon the suspension is added for 1/2 hour Stir at 70-75, cool to 40-45 ', suction under hydrogen, wash with plenty of air-free water and dry at <B> 80-100' </B>.

   21 parts of brown quinhydrone are obtained in the filtrate in addition to unchanged, unreacted dihydroflavanthrone.

 

Claims (1)

PATENT CLAIM: Process for the production of a quinhydron, characterized in that the leuco compound of the flavanthrone is allowed to act on the flavanthrone. The new quinhydrone is a brown, sandy powder that dissolves in concentrated sulfuric acid with an olive-green color and dyes cotton from a dark blue-violet vat in yellow tones. It is very easy to shred.