DK142357B

DK142357B - Process for the preparation of 2,6-ditert.butyl-4-methylphenol.

Info

Publication number: DK142357B
Application number: DK253476A
Authority: DK
Inventors: Ivan Egorovich Abramov; Felix Borisovich Gershanov; Vladimir Romanovich Dolidze; Nina Vasilievna Zakharova; Alexandr Grigoriev Liakumovich; Jury Ivanovich Michurov; Vasily Dmitrievich Popov; Grigory Iosifovich Rutman; Zoya Stepanovna Shalimova
Original assignee: Sterlitamaxky O Promy Zd Proiz
Priority date: 1976-06-08
Filing date: 1976-06-08
Publication date: 1980-10-20
Also published as: DK142357C; DK253476A

Description

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Den foreliggende opfindelse angår en fremgangsmåde til fremstilling af 2,6-ditert.butyl-4-methylphenol.The present invention relates to a process for the preparation of 2,6-ditert.butyl-4-methylphenol.

2.6- Ditert.butyl-4-methylphenol er et effektivt stabiliseringsmiddel for forskellige typer af syntetisk 5 kautsjuk, det beskytter vulkanisater baseret på naturlig kautsjuk og på butadien-styren-, isopren-, butadien-, butadien-nitril- og chloropren-kautsjukker mod termisk ældning og delvis mod lysældning, og det anvendes også i lyse og farvede kautsjukgenstande. 2,6-Ditert.butyl-4-10 methylphenol anvendes som et termisk stabiliseringsmiddel for polyethylen- og polypropylen-fibre og er også et effektivt stabiliseringsmiddel for næringsmiddelprodukter.2.6- Ditert.butyl-4-methylphenol is an effective stabilizer for various types of synthetic rubber, protecting natural vulcanizates based on natural rubber and butadiene-styrene, isoprene, butadiene, butadiene nitrile and chloroprene rubber sugars thermal aging and partly against light aging, and it is also used in light and colored rubber articles. 2,6-Ditert.butyl-4-10 methylphenol is used as a thermal stabilizer for polyethylene and polypropylene fibers and is also an effective stabilizer for food products.

Pra britisk patentskrift nr. 1.297.088 kendes en 15 fremgangsmåde til fremstilling af 2,6-ditert.butyl-4-methylphenol ved hydrogenolyse af Ν,Ν-dimethyl-(3,5-di-tert.butyl-4-hydroxy-benzyl)-amin i decalin i nærværelse af en katalysator indeholdende Ni, Al og Ti.British Patent No. 1,297,088 discloses a process for the preparation of 2,6-ditert.butyl-4-methylphenol by hydrogenolysis of af, Ν-dimethyl- (3,5-di-tert.butyl-4-hydroxy). benzyl) -amine in decalin in the presence of a catalyst containing Ni, Al and Ti.

Ulempen ved denne kendte fremgangsmåde består i, 20 at der under hydrogenolyse sker en partiel harpiksdannelse af Ν,Ν-dimethyl-(3,5-ditert.butyl-4-hydroxy-benzy3>-amin i decalin. Den isolerede 2,6-ditert.butyl-4-methyl-phenol indeholder ca. 5% harpiksdannelsesprodukter, der bibringer produktet en gul farve.The disadvantage of this known process is that, during hydrogenolysis, a partial resin formation of Ν, Ν-dimethyl- (3,5-ditert.butyl-4-hydroxy-benzyl) -amine in decalin occurs. ditert.butyl-4-methyl-phenol contains about 5% of resin-forming products which give the product a yellow color.

25 Til isolering af 2,6-ditert.butyl-4-methylphenol fra reaktionsblandingen kræves endvidere rektificering af reaktionsblandingen og genvinding'af opløsningsmiddel, hvilket gør fremgangsmåden mere kompliceret og kostbar.Further, for the isolation of 2,6-ditert.butyl-4-methylphenol from the reaction mixture, rectification of the reaction mixture and solvent recovery is required, making the process more complicated and costly.

2.6- Ditert.butyl-4-methylphenol fremstillet ved 30 nævnte fremgangsmåde kan kun anvendes til næringsmiddelprodukter efter en kompliceret rensningsproces, f.eks. ved rektificering eller krystallisation.2.6-Ditert.butyl-4-methylphenol prepared by said process can only be used for food products after a complicated purification process, e.g. by rectification or crystallization.

Den foreliggende opfindelse har til formål at forbedre fremgangsmåden til fremstilling af 2,6-ditert.bu-35 tyl-4-methylphenol ved katalytisk hydrogenolyse af Ν,Ν-dimethyl- (3,5-ditert.butyl-4-hydroxy-benzyl)-amin med henblik på at simplificere processens teknologi, sænke 2 142357 omkostningerne for produktet og forbedre produktets kvalitet.The present invention has for its object to improve the process of preparing 2,6-ditert.butyl-4-methylphenol by catalytic hydrogenolysis of hydrogen, yse-dimethyl- (3,5-ditert.butyl-4-hydroxy-benzyl) ) -amin in order to simplify the technology of the process, lower the cost of the product and improve the quality of the product.

Nævnte formål er nået gennem en fremgangsmåde til fremstilling af 2,6-ditert.butyl-4-methylphenol ved ka-5 talytisk hydrogenolyse af N,N-dimethyl-(3,5-ditert.butyl- 4- hydroxy-benzyl)-amin i nærværelse af en sammensmeltet katalysator indeholdende nikkel, aluminium og titan i et organisk opløsningsmiddel, hvilken fremgangsmåde ifølge opfindelsen er ejendommelig ved, at der som opløsnings-10 middel anvendes 2,6-ditert.butyl-4-methylphenol.Said object has been achieved by a process for the preparation of 2,6-ditert.butyl-4-methylphenol by catalytic hydrogenolysis of N, N-dimethyl- (3,5-ditert.butyl-4-hydroxy-benzyl) - amine in the presence of a fused catalyst containing nickel, aluminum and titanium in an organic solvent, the process of the invention being characterized by the use of 2,6-ditert.butyl-4-methylphenol as the solvent.

Anvendelsen af 2,6-ditert.butyl-4-methylphenol som opløsningsmiddel gør det muligt at simplificere processen til isolering af 2,6-ditert.butyl-4-methylphenol fra reaktionsblandingen ved at eliminere rektificeringen af 15 reaktionsblandingen og genvinding af opløsningsmiddel.The use of 2,6-ditert.butyl-4-methylphenol as a solvent enables the process of isolating 2,6-ditert.butyl-4-methylphenol from the reaction mixture to be simplified by eliminating the rectification of the reaction mixture and solvent recovery.

Endvidere hæmmes under hydrogenolyse i nærværelse af 2,6-ditert.butyl-4-methylphenol sekundære harpiksdannelsesprocesser, således at det bliver muligt at vinde 2,6-ditert.butyl-4-methylphenol af ønsket renhed uden 20 komplicerede rensningstrin.Furthermore, during hydrogenolysis, in the presence of 2,6-ditert.butyl-4-methylphenol, secondary resin formation processes are inhibited so as to obtain 2,6-ditert.butyl-4-methylphenol of desired purity without 20 complicated purification steps.

Denne hæmmende virkning på sekundær harpiksdannelse kan illustreres af følgende hydrogenolyseresultater * opnået ved anvendelse af henholdsvis decalin og 2,6-di-tert.butyl-4-methylphenol som opløsningsmiddel: 25 Temp. Opløsningsmiddel Reaktionstid Harpiksindhold °C_timer_vægt%_ 120 2,6-ditert.butyl- 2,5 intet 4-methylpheno1 140 " 1,5 intet 30 120 decalin 3,0 2,0 140 " 3,0 4,0This inhibitory effect on secondary resin formation can be illustrated by the following hydrogenolysis results * obtained using decaline and 2,6-di-tert-butyl-4-methylphenol as the solvent, respectively: 25 Temp. Solvent Reaction time Resin content ° C_hours_wt% _ 120 2,6-ditert.butyl-2,5 none 4-methylphenol 140 "1.5 nothing 30 120 decalin 3.0 2.0 140" 3.0 4.0

Det fremgår af denne tabel, at 2,6-ditert.butyl-4-methylphenol øjensynligt hindrer dannelsen af quinoide strukturer på en katalysator i fravær af oxygen, hvilket 35 muligvis danner grundlag for forbindelsens hæmmende egenskaber.It can be seen from this table that 2,6-ditert.butyl-4-methylphenol apparently inhibits the formation of quinoid structures on a catalyst in the absence of oxygen, possibly forming the basis of the compound's inhibitory properties.