CH220962A - Process for the preparation of a lower carboxylic acid ester of tocopherol. - Google Patents

Description

  

  Process for the preparation of a lower carboxylic acid ester of toeopherol. d, 1-Tocopherols (synthetic vitamin E) can be produced by condensation of trimethyl hydroquinone or dimethyl hydroquinones with phytol or phytyl halides. These tocopherols are gradually destroyed when exposed to oxygen, moisture and light. Esterification makes them durable.



  It has now been found that lower carboxylic acid esters of d, 1-tocopherols can be obtained by esterifying the condensation products of trimethylhydroquinone or dimethylhydroquinones with phytol or phytyl halides without prior purification with the lower carboxylic acids and esterifying the resulting esters in be cleaned in the usual way. Purification is advantageously carried out by distillation in a high vacuum.

   The process delivers very good yields in a short and gentle way. .- The subject of the present patent is a process for the production of a lower carboxylic acid ester of tocopherol, which is characterized in that the crude condensation product of trimethylhydroquinone and phytol is treated in acidic solution with an acetylating agent and the resulting ester is purified. The ester is advantageously worked up by distillation in a high vacuum.



  The hitherto unknown d, 1-acetyl-a-tocopherol is a pale yellow, viscous oil which boils at 224 ° at 0.3 mm pressure; the refraction exponent n; is 1.4967. It is stable and in methyl alcoholic solution does not reduce silver nitrate and Tollen's reagent only gradually. By saponification, e.g.

   B. with methyl alcoholic potassium hydroxide in the absence of air, the free tocopherol can easily be recovered. The d, l-acetyl-a-tocopherol should be used as a drug.

             Example: The solution of the condensation product of 200 parts of phytol, 100 parts of trimethylhydroquinone in 500 parts of ether and 1000 parts of benzene in the presence of 50 parts of zinc chloride and a rapid stream of dried hydrochloric acid gas at 50 is after the zinc chloride has been extracted by washing with water dried and evaporated. The residue is then heated in a carbonic acid atmosphere with 300 parts of acetic anhydride in an oil bath to <B> 150 '</B> for 2 hours and then distilled in vacuo.

   After removing the acetic anhydride, the distillation is carried out in a high vacuum and 215 parts of pure d, 1-a-tocopherol acetate are obtained.

 

Claims (1)

PATENT CLAIM: A process for the production of a lower carboxylic acid ester of tocopherol, characterized in that the crude condensation product of trimethylhydroquinone and phytol is treated in acidic solution with an acetylating agent and the resulting ester is purified. The hitherto unknown d, l-acetyl-a-tocopherol is a light yellow, viscous oil, which at 0.3 mm pressure boils at 224 °; the refraction exponent n "" is 1.4967. It is stable and in methyl alcoholic solution does not reduce silver nitrate and Tollen's reagent only gradually. By saponification, e.g. B. with methyl alcoholic potassium hydroxide in the absence of air, the free tocopherol can easily be recovered. SUBSTANTIAL CLAIM: Process according to patent claim, characterized in that the ester is distilled in a high vacuum.