CH227705A - Process for the preparation of diphosphoric acid esters of nucleus alkylated derivatives of hydroquinones. - Google Patents

Description

  

  Process for the preparation of diphosphoric acid esters of aluminum ethylated lobes of hydroclinones. The action of phosphorus oxyhalides on phenols gives dihalides of phosphoric ester acids. Such halides are generally easy to isolate in one form, since they can be distilled under reduced pressure.

    To obtain the free arylphosphoric acids from arylphosphoric acid halides, ground the halides with water. If the free phosphoric acids are easily soluble in water, they are difficult to prepare in pure form because the aqueous solution still contains hydrohalic acid. The hydrohalogen acid can be removed by evaporation.

   In doing so, however, the phosphoric ester acids are kept under the influence of the halogenated hydrochloric acid for a long time. ii as usually leads to an often extensive deterioration of the ester acid ...

   If iarcizi neutralizes the aqueous solution, which contains both the aryl phosphoric acid and the hydrogen halide, y acid is avoided. a saponification of the aryl phosphoric acid, but the end products sought have to be separated from the likewise soluble halogen alkali salts, which can only be carried out with considerable losses.

   A separation of the aryl phosphoric acids after the decomposition of their halides with water from the hydrohalic acid has already been achieved by extracting the arylphophosphoric acid from the aqueous solution by shaking it out with ether. This measure only achieves the goal if the phosphoric acid ester of a monohydric phenol is present,

       respectively only one phosphoric acid residue is present in the molecule. To isolate diphosphoric acid esters of hydroquinones or their nucleus-alkylated derivatives, which, as is already known, are obtained by decomposition of the phosphoric acid ester halides with water, this procedure is not possible because. these diphosphoric acid esters cannot be removed from the aqueous solution with ether.



  As has now been found, the difficulties can thereby be eliminated. that the aqueous solutions of the phosphoric ester acids are extracted with an alcohol which is sparingly soluble or insoluble in water and which has 4 to 12 carbon atoms in its molecule. For example, the following can be used: butyl alcohol, amyl alcohol, octyl alcohol. Do; decyl alcohol, benzyl alcohol, cyclohexanol, etc.

   When the alcohol is removed, suitably under reduced pressure, the diphosphoric ester remains in the pure state. It can be converted into the corresponding salt in the usual way by adding the calculated amount of a base.



  The diphosphoric acid, nucleus-alkylated derivatives of the hydroquinones are used as pharmaceuticals.



  <I> Example 1: </I> The distilled by dissolving 10 parts of 2-methyl-1,4-naphthohydroehinone - diphosphory 1 cblorid (Swiss. Patent No. 218523) in 10 parts of ether and adding 10 parts The mixture obtained is separated in a separatory funnel. The watery layer is repeated several times. Ether washed out. All ether extracts are discarded. The aqueous solution is then extracted one after the other with 5 parts each of isobutylcarbinol until the aqueous layer is, so to speak, colorless.

   The combined Isobutylca.rbino@lauszüge are dried. The crystalline residue is almost pure diphosphoric acid ester of 2-bfetliyl-1,4-naphthohydroquinone.



  <I> Example 2: </I> The aqueous layer is separated off from the mixture obtained by dissolving? 0 parts of trimethylhydroquinone-dipho @ sphoryl chloride in? 0 parts of ether and adding 20 parts of distilled N # @ Tasser, with further Extracted small amounts of ether, separated again and then one after the other with 5 parts each.

       Benzyl alcohol extracted until the benzylallzoliolisclie solution is colorless. The benzyl alcoholic solution is dried by shaking over '2 \ Tatrium: sulfate, filtered and evaporated in vacuo. The residue is, so to speak, pure trimethylhydroquinone dipliosplioic acid ester.



       Example: The mixture obtained by dissolving 2 parts of thi - mohydroquinone-diphosphoryl chloride (represented by thymolyl droquinone and phosphorus oxychloride in pyridine solution) in 4 parts of ether and adding 8 parts of water - the almost colorless layer is separated and discarded. The aqueous layer is extracted twice more with 4 parts of ether.



  The aqueous layer in which the phosphoric ester acid is dissolved is then shaken with 8 parts of amyl alcohol until the extracts are colorless. The amyl alcohol extracts are combined and evaporated in vacuo. The extract is almost pure diphosphorus: stearic acid from thymoquinone.



       Be; sla; el i: From the solution of 1 part of 2-ethyl -1., 4-naplithohy drochinon-dipliosphory 1-chloride (prepared from 2-.3thy1-l., 4-nap @ tho-hydroquinone and phosphoroxyliloride in pyridine solution)

      The solution obtained in 2 parts of ether and the addition of 4 parts of water, the aqueous layer in which the phosphoric ester acid is now dissolved is separated, shaken twice with ether and then exhaustively extracted with cytlohexanol.

   When the cyclohexanol solution is concentrated, the extract obtained is the phosphorous ester acid of 2-ethyl-1,4-naphthohydroquinone. It's a viscous, oily liquid.

 

Claims (1)

PATENT CLAIM: Process for the preparation of diphosphoric acid esters of nucleus alkylated derivatives of hydroquinones from the solutions obtained by treating their phosphoric acid ester halides with water, characterized in that the aqueous solutions are treated with alcohols which in their b'Iole- kül 4-12 have carbon breaths, drawn off and the alcohol is distilled off from the extract obtained in this way.