DE835147C - Process for the production of phenols - Google Patents

Description

Process for the preparation of phenols The l? Rtindtiiig relates to a process for the preparation of phenols from cyclic compounds belonging to the group consisting of isophorone and its homologues and is specifically directed to a process for the catalytic conversion of isophorone (3, 5, 5- Trimethylcyclohexen-2-one-r) in 3, @ - \ vlenol (3, 5-I) imethylphenol).

The method according to the invention is carried out by applying the (): inoculation of isophorone or a homologue of isophorone at a temperature in the range \ (in about 400 'to about 65o ° with a fixed hatalvsator, which consists of an activated, d. H. : i <lsorl> there is already an activated aluminum oxide Contains aluminum oxide in a predominant amount, should be brought into contact.

The process is applicable to the conversion of isophorone or its homologues, such as the homoisophorone, to the corresponding phenolic compounds. Suitable homologs are e.g. B. Compounds in which one of the methyl groups des Isophorone or several by other alkyl radicals, such as the ethyl, propyl, isopropyl, Butyl, sec. Butyl, isobutyl, tertiary. Butyl, amyl or hexyl radical, substituted are.

Activated alumina has been found to be an excellent catalyst for the above reactions. These activated aluminum oxides consist entirely or predominantly of aluminum oxide-a-monohydrate and hzw. or y -aluminum oxide; they are characterized by their highly active adsorbing properties and can be produced from the so-called y-aluminum oxides of the Haber system. H a be r (Naturwiss. 1 3, 1007 [1925]) divides the different forms of aluminum oxides into two systems and denotes them as y, system and f-system, according to their behavior in the Fitzen. The y -_ @ ltiniiniutnoxyde of the Haher class fication include the actual γ-aluminum oxide ouch! all so-called hydrated - '\ luininiutnoxyde, die i, e, in heating over the, -form in a-aluminum- oxides converted to earth. On the other hand, include the r, '-_ \ lumitiium oxides of the Haber system aluminum uliniunioxyde, like diaspore, which cures when heated can be converted into x -: \ lumiiiiunioxyd without to go over the y shape. This classification the aluminum oxides in; - and / 3 systems 11 al) it must not be confused with the Classification into the fundamental real . \ luminitinioxydformen, which are only used for classification the usual forms of alumina in two lwstinitute (irupl) en serves. The various so-called hydrated aluminum oxides, which form the y-systeine gc @ m: il @ assigned to the Hal) crschen classification are therefore quite different from the real lichen #, - altinium oxides, and diaspore is not "-. \ ltitniniumoxide. 1) ic aluminum oxides, which oil when heated (las; - aluminum oxide converted into a-aluminum oxide tvan (being telt, which means the # system of Hal) sclten classification are assigned and the active fourth or adsorptive _ @ luminitinioxyde include Imw. form. those involved in the procedure rlcr invention as a catalyst hzw. Catalyst- are used are: t. . \ ltiniiniutnoxv (i- x -trihydrate (Gil) 1) sit hz.w. llv (lrargillit): this form is slightly synthetic i # crsMllmr and occurs naturally as a mineral shear chlasite and as a component of various I% uxhe forward. 2.: \ ltltiiiniunioxyd-f-trihydrate (bayerite) is iso- worl) h with Eydrargillit find comes in nature n; clit before, but can be synthetic by suitable Ilnstellung der AusfälhmgAwdiugungeli generated will. 3.: Aluminum oxide-x-motiohydrate (boehmite) becomes by partial dellydratation of one of the above tri h_ydrate formed. ' 1. "-: \ luniiniumoxyd, a meta-stal) iles mass- free oxide, which does not occur in nature, but through carefully controlled dehydration of the three hydrates mentioned above can. ;. ('# El-shaped aluminum oxide. These often occurring aluminum oxide form is freshly fallen "state amorphous, but shows after the Aging lx # i of the X-ray analysis the eliarak- teristic I.itiien von Boehmite. With further aging the precipitation is gradually in Eaverit and finally lich converted into llydrargillite. 6. Bauxite, a mineral with an alternating sanitnetisetzting, that from an extraordinarily fine distributed mixture of two or more of the 1) e- knew aluminum oxides and certain argillites between residues and no whydrates of aluminum oxides, as previously indicated was nrnmnen. A preferred type of activated aluminum oxyden is produced by the dehydration of aluminum oxy (ltrilivdrat.crystallized from alkali aluminate Solutions, made. Irish lwsmiders eligible Material of this kind is (read from k <»upaktem Alti- niinium oxide trihydrate manufactured product, like it z. 11. in U.S. Patents r 868 869 and = 015 593 1) esclirielwn is. Natural aluminum Oxides, like bauxite, are generally not so as effective as synthetic. \ luniitiiunloxv (1e, what in essential to the presence I) more considerable Proportions of iron, silica and other is due to impurities that the selec- reduce the efficiency of the catalysts and desired cleavage reactions 1) selfish. Ge @ t-isse selected bauxites, such as the one called "Porocel" ini Trade 1wEnMiche activated bauxite, range in their clock effectiveness to the synthetic aluminum oxides and can act as a catalyst sator, iiishes special because of their proportionate low cost, 1) your procedure according to the Invention being used. The various hydrated aluminum oxvde, as they are oheil heschi-iel) eil, can be dehydrated to the desired extent, ie activated will. The \ -laxitnutn of Adcorlstionsvernlögens usually corresponds to a water content between approximately ; and about 12 "-o. and on such Water content dehydrated substances are very suitable. 1) he different. \ Lutniniumoxvde can however, it is also made more effective by it further hydration up to a water content from less than about 0 "-o: in this hall the people stand . \ luniinitltnoxy (le mainly from (lern ol) (, n 1) e- srhriel> rnen # _ @ luminiumoxy <l. \\ 'ctm 1) when carrying out the procedure the invention uses a mixed catalyst will. such a catalyst mainly contains an activated _ \ lttniinitinir) xvd and a low- ren, but not insignificant share, in all- common between o.5 and lo ° 'o, preferably between o.3 and io "',). of a catalytically dehydrated effect of sedentary metal or a Metal bracing. Such mixed catalysts. in Genes the activated aluminum oxide by weight, predominates and IA dencu the dehydrogenating metal or the dehydrating (h metal compound of the oil Hächte des _ \ ltintiniutnoxyc? S cinverleil) t is, lwsitzctt the catalytic egg; gensclmhcn loading substances in Connection with the idysical structure and the lwson (iers high porosity: it de: activated aluminum miniunuixvds. The added (lchy (lricren (lc \ Ieta11 or the all-metal extension came to the whole "fil an (read activated _ \ luminit, nu) @y (1 chemically bound: hurries or can only be reached at the O1) Area of the activated = \ uminiunioxyds physically be bound or divorced in the pores al) soap: one o (! (- i- several of these metals ole metal compounds clietnisch asses the active fourth Altiminiunioxyd gel) unden: hurries. while one or more of these Stnffv physically all the surface read aktiviet-tcti: \ lutliitiitililoxvcls bound or in his you are geschiedei al). 1) ie Mhcltkamlysatot-cn. the geniäl. l of the invention dung 1) ei der 1: atalvtisclieli conversion of iso- phoron or its homologue iti aromatic` liy (lroxvlgroup partial connections with the equal number of suspended carbon atoms w-ends will be 1 «iiines, contain apart from the active fourth: \ luniiniumoxvd another dehydrating one Metal or a metal compound, the given if chemically bound to the: \ luniiriiunioxyd is like a 1Ic ° talloxy (l. -sultide, -carbonate, -chromate, -clironiit. -niolyl) clat or - @ volframat. Very active iiatalvsati> reii "are, for example, those who have nickel, iron. Cobalt, manganese, \ -atiaditini, chromium, titanium, zircon, (_cr, osmitiin, zinc, L'ran or tantalum or a 1_erbin (ment of these metals contain, .which Olxi-H; icllc (tes activated aluminum oxide is absorbed. 13c are preferred mixed catalysts (here, w, elclie 2 activated = \ ltitniiiiiimoxyd and a or several iron, cobalt or (their in which (read 'metal in one positive or negative chemical bond can lie. A particularly preferred sub- group of mixed catalysts includes those that activated. \ ltlniiniunioxvd and an oxide or several from I? iseil. Cobalt and / or chromium lialteii. _ \ iidcre very active mixed catalysts hold apart from activated alumina sulphate fide viiii metals dci- left row of the sixth GruIlllv des 1lfriodisclt: @ i1 systems or mixtures this 1letallsulticic finite other 1letallsulfideli, z.13. Wolfrainstilfide and Nickel Sulphide. The 1mixed catalvsators kiiiiiieii z. 13. Be made by linllrägniereii of the activated alumina with an oil, preferably an aqueous solution, ciiier \ "founding of the desired metal and subsequent drying of the mixture. (If desired, the catalyst can be made from active fourth .- \ luminiumoxy <1 can be combined with smaller amounts, e.g. B. i to ioo / o, of alkali metals or t? rdalkalinietall, which preferably are incorporated in Forni ilii-er \ 'erliiudtirigen, z. B. as oxides, MIy (lroxy (le. nitrates, carbonates, sili- cate. Alutninatc, Forniiate and Oxalate. The catalysts can be in any form be used, e.g. l3. in the form of grains, liügelchen, little pieces. Powders of any desired ten "hcilrhengr <il '@ c. The one in the reaction zone, e.g. cillein reaction space or a reaction chamber, ein> rachtc I @ atalvsatar can z. B. by heating \ on ritil.9cn ailf the desired: \ rl> eitsteinperatur gehraclit or be held on this, with (read ketone at the desired space velocity speed (i.e., the number of moles of vapor . \ tisgaiigsmaterials, (here finitely one liter of the catalyst sators per hour are brought into contact) in State of vapor through the reaction zone is sent. The space velocity and the temperature may vary depending on your particular fabric being treated and / or your catalyst used for Achieving high sales at a useful speed speed can be adjusted, being undesirable \ 'el>`#nreahtioneu, like 7replaced with ringspal- tion, essentially to be avoided. Satisfied- The results are generally given with spatial speed ranges from about 2 to 75 obtain. The preferred space velocities, especially in the production of 3,5-lylenol from isophorone, are in the range from about 8 to: 10 at temperatures from about 45o to 55o ".

The preferred temperature range for carrying out the catalytic Conversion according to the invention is between about 400 'and about 65o °. When using of isophorone as the starting material were optimal yields of 3, 5-yylenol Temperatures between about 4oo ° and about 550c obtained. "In general, the Achieving a higher degree of conversion at lower temperatures in the above Range of low space velocities used while at high temperatures To avoid undesirable side reactions, a high level of spatial inclusion is required are.

The process can be carried out at any suitable pressure and batchwise, intermittently or be continuously permeated. Preferably the process is continuous carried out, the starting material in a special chamber or in the evaporated front part of the reaction chamber and then with the desired space velocity is carried out through the reaction zone heated to the reaction temperature. . \ ticli liquid starting material can evaporate in the actual reaction chamber will.

If desired, the process in the presence of an inert Diluents are carried out, e.g. 13. of hydrogen, nitrogen, water vapor or certain hydrocarbons. This can be done to equalize the temperature in the Reaction zone, achieving a uniform reaction, quality, earthiness, limitation the occurrence of undesirable side reactions and also for the purpose of extending the service life of the catalytic converter can be an advantage.

The invention is illustrated by the following examples, which are particular aim at the catalytic conversion of isoplhorone in 3,5-diniethylphenol, further explained.

All attempts were made in an electrically gelieizteti, seamless iron Reaction tube in which the catalyst was housed carried out. The two Ends of the tube were not heated and did not contain any catalyst. The preheated Ketone was in contact with the catalyst kept at a given temperature click through the reaction tube; the reaction products were then carried out passed through the vain water-cooled compressor, and the liquid formed in this way Product was tested to determine the total conversion and the yield of phenols. Example i A catalyst with the surface of activated alumina was used incorporated ferric oxide used; the reaction tube was kept at about 500 °. Preheated isophorone was vaporized through the reaction zone and in contact carried out with the catalyst at a rate of 33; 6. the analysis the result of the reaction products was that about 40 percent by weight of the isophorone reacted and that about 84 percent by weight of the reaction products from phenols, predominantly 3, 5-dimethylllienol, passed.

Example 2 The catalyst and reaction temperature were those of the example i; the space velocity of the isophorone passed through the catalyst has been reduced to 8.4. The conversion increased to about 62 percent by weight of the introduced isophorone. About 75 percent by weight of the isophorone converted were converted to phenols.

In game 3 isophorone was traveling at a space velocity of about 25.2 at about 500 ° via a largely dehydrated activated aluminum oxide, that mainly consists of y aluminum oxide. existed, led. The investigation showed that about 55 percent by weight of the introduced isophorone had reacted; The yield of phenols was about 75%.

Example The catalyst contained activated alumina on the surface incorporated cobalt oxide. This catalyst produced isophorone vapors at 500 ° and sent through at a space velocity of 16.8. Analysis showed that 68 weight percent conversion of isophorone had occurred. the The yield of phenols was about 71%.

Example The catalyst used in this example was that of Examples i and 2. The reaction temperature was also 500 °. Instead of Passing isophorone alone over it was carried out in vapor form along with water sent the catalyst through. The molar ratio of isophorone to water was 8.4 to 24.2; the space velocity of the mixture was about 32.6. It had about 72 percent by weight of the introduced isophorone reacts. The phenol yield was about 82 per cent.

Example 6 The catalyst consisted of activated aluminum oxide, which mainly contained aluminum oxide amonahydrate and only a little γ-aluminum oxide. The catalyst charged to the reaction zone was maintained at about 550 ° and a preheated vapor mixture of isophorone and water (in a mole ratio of 8.4 to 24.2) was passed through the catalyst at a space velocity of about 32.6. About 90 percent by weight of the supplied isophorone had reacted; the yield of phenols was about 63%. 1); e Attalv: e which, according to (1 (211t above example) produced phenols. dali they average from 90 to 92 percentages (3, 5-di- methylphenol) bestatideii. The overall conversion and overall yield of your desired xylenol katitt by returning the not replace isophorones (itircli the reaction zone be liöht. l3 ice 1> ie 1 The catalyst consisted of iron oxide holding activated alumina; he was during the entire conversion reaction aul ' held at a temperature of about 500. Homo- isophoron (made by condensation of Methyl ethyl ketone) was pounded and steamed statatici with a space velocity of about 2o sent through the reaction chamber. Approximately 47% of the homoisol) was converted with phenols. changed. In the same way, a C, 2-ketort, creates four molecules through condensation Acetone, which has a ring of 6 carbon atoms reit only contained a @ing double bond that contained Effect of adsorbed aluminum oxide exposed about 5oo °. Here, too, pheno- generated connections. The in the method according to the invention used catalysts are among the reaction conditions are quite stable and can therefore for a long period of time without significant can be used to reduce their activity. if the catalytic converters after a long period of use gradually show decreased activity, as was found the original activity by oxidizing the carbon deposit practically table can be completely restored, preferably at temperatures that are not around 700 ° significantly exceed. This oxidation can be done without Removal of the exhausted catalyst from the Reaction zone by passing oxygen through. Air or a Geniiscli N-on air and one inert carrier gas, e.g. ] ». Nitrogen, both desired temperature through the regenerative the catalyst can be acidified. example The catalyst consisted of;, -_ @ aluminum oxide. which has already been used for the catalytic dissolution of iso- phoron to essentially from 3, 5-dimethylplienol existing phenols have been developed uni Passing a mixture of air and Nitrogen at about 700 for about i to i1 / 2 Hours had been reactivated. Through this regenerated catalyst were then at about 500 'isophorone vapors with a space velocity speed of about 33.6. The Um- conversion amount about 4t weight percent and the Phenolatisl) utes about 6S '# o. The same fatal saw w-ui-ile then in twelve # ve 1 teren process' iil "eii \ -erN # eiidet. in total a little less than 1 kg iso1ihoron treated became. The catalyst volume was 80 ccm. After every experience, the catalyst was in the manner described ol> eti. nerates. After your last of these proceedings the catalyst was reactivated and then around the catalyst the same reaction conditions used. It was found that even after repeated regeneration of the cat- l @ satt »- still had the same activity that conversion% of isophorone about 42 percent by weight and the yield of phenols was about 70%. Although the reaction product to the recovery the 1'lic-iiole treated in different ways N \ "r- can, \ N ird a @ 'et-faliren is preferred in which the N-liquid role of reaction product with an alkali solution, e.g. K an aqueous sodium hydroxide liisting extracted @ \ ird. The alkaline solution the I'lienole. z. I @. of 3, 5-Diniethv.ll> henol that on this', disfigured, can then be neutralized least, e.g. ii, by III'cililendiox_vd or hydrochloric acid, and the released plienols can, for. B. by iil> liche 1) estillati <»i (xler also by separating the Phases @ ei @ @mnen @@ - earth. For production of practically rc @ inein 3. 5iI) methylphenol can do that product obtained by I) estillati @ m from a suitable coliles \\ asserstottfraktion, z. B. Octanes, be recrystallized. Since isophorone is in a Very good dissolution of the sodium implant enolates l ('islicli is unreacted isophorone in the liquid raw reaction mixture is present, it is advisable to take the alkaline solution of the phenols once or several times with a selective solution medium, such as aromatic hydrocarbons, e.g. B. Benzene or saturated hydrocarbons or ethers, which are able to selectively dissolve the isophorone, ztt extract.

Claims (4)

PATENT CLAIMS: i. Process for the preparation of phenols from isophorone or its homologues, characterized in that these cyclic ketones are brought into contact in the vapor phase at a temperature in the range from 400 to 65o ° 'with a solid catalyst consisting of activated aluminum oxide or predominantly containing activated aluminum oxide . 2. Procedure according to Claim i, characterized in that the activated alumina catalyst includes the catalyst and a minor, but not inconsiderable, amount of a metal or a There is no metal bond with a deliv-erating effect. 3. The method according to claim 2, thereby gel; etinzeichuet. that the clehvdrierende metal, \ - erwind an Ox_vcl of iron. Cobalts or Clironis is. 4. The method according to claim i to 3, characterized characterized in that 3, 5-xylenol by passing isophorone vapors through the catalyst at a space velocity z, # mix about 8 and 40 moles per Liters of catalyst volume and per hour is produced.