By Their Attorney 7.54 Patented Feb
Total Page：16
File Type：pdf, Size：1020Kb
Feb. 19, 1952 D. B. LUTEN, JR., ETAL 2,586,070 PROCESS FOR PRODUCING PHENOLIC DERIWATIVES Filed Nov. 3, 1947 Aromatic Mixture of A and 5 Recycle. Additament and/6r Portion of Product Addition Product AC Admixed with B b separator Desired Derivative A inventors: Daniel B. Luter, Jr. Aldo DeBenedicts by their Attorney 7.54 Patented Feb. 19, 1952 2,586,070 UNITED STATES PATENT OFFICE 2,586,070 PROCESS FOR PRODUCING PHENOLC - DERVATIVES Daniel B. Luten, Jr., and Aldo De Benedictis, Berkeley, Calif., assignors to Shell Develop ment Company, San Francisco, Calif., a corpo ration of Delaware Application November 3, 1947, Serial No. 783,832 13 Claims. (CI. 260-624) 2 This invention relates to a novel process for divided, part being recycled to produce more of the production of derivatives of aromatic organic the addition product, and part being taken as compounds, and to novel compounds produced by the final product. - Said process. Another preferred embodiment of the present In general, aromatic compounds are easily invention contemplates the formation of an ad obtainable from natural or synthetic sources as dition product wherein one component thereof components of mixtures of closely related com is the aromatic compound from which the desired pounds, such as mixtures of isomers. In order derivative may be prepared, while the other com to prepare derivatives from an aromatic com ponent is a material which emerges from the pound contained in such a mixture, it is cus O process substantially unchanged, and, after Sep tomary first to separate the aromatic compound aration of the desired derivative, may be re from the mixture and then to treat or react it cycled in the process. to form the desired derivative. An alternative A still further preferred embodiment of the method is to treat or react the mixture of ma present invention contemplates the formation of terials to form the desired derivative, which is 5 an addition product wherein one component then separated from the reaction mixture. Both thereof is again the aromatic Compound from of these processes, however, in some instances which the desired derivative may be prepared, are extremely difficult and uneconomical. In while the other component is a material which the first method, for example, it may be prac also forms a valuable derivative during the re tically impossible to separate the aromatic com 20 action. ponent, at least by ordinary procedures, while in The present invention is especially advanta the latter method, compounds other than the de geous where the aromatic compound, from which sired derivative are usually produced, which con the desired derivative may be prepared, is a com Sumes the reactants to no advantage and fre ponent of a mixture of materials from which it quently leaves a difficult problem of separation of 25 cannot be separated except by difficult, laborious the desired derivative. As illustrative of aro and uneconomical methods. For example, if it matic mixtures wherein the Separation of the is desired to prepare 2,4-dimethyl-6-tertiary components presents unusual difficulties are mix butylphenol from 2,4-xylenol, which is usually tures of the isomers of cresols, xylenols, xylenes, a component of a multi-component System of dimethyl naphthalenes, toluidines, xylidines and 30 phenols containing 2,4-xylenol, 2,5-Xylenol and picolines. 2,3-xylenol, it has heretofore been necessary to It has now been found that aromatic deriva separate the 2,4-xylenol and to subsequently tives may be produced economically, convenient butylate the separated 2,4-xylenol, or to butylate ly, and in good yield from multi-component SyS the mixture of materials and then recover the tems containing as a component thereof the aro desired product from the reaction mixture. matic compound to be treated to form the de These methods are difficult and uneconomical. sired aromatic derivative, by mixing said multi In the first method, it is practically impossible component system" with a material capable of to separate 2,4-xylenol from the mixture of ma forming an addition compound with said aro terials by ordinary methods because the boiling matic compound, separating the resulting addis 40 points of the various components are identical, tion product from the other substances of the or practically identical, and therefore it is nec admixture, treating or reacting the addition essary to resort to unusual, difficult and uneco product so as to prepare the desired derivative nomical processes. In the second method, where of the aromatic compound, and recovering said the mixture of xylenols is butylated prior to Sep aromatic derivative. aration, a mixture of products is obtained, where A preferred embodiment of the present inven by a major portion of the butylating agent, such tion contemplates the formation of an addition as isobutylene, may be wasted by the formation product wherein one component thereof is iden of by-products, and the separation of the desired tical with the desired aromatic derivative, and product from the mixture remains difficult. Ac the other component is the aromatic compound cording to the present invention, these difficulties to be treated to form the desired derivative there are overcome in this instance by adding 2,4-di of, separating the addition product from the re methyl-6-tertiary-butylphenol to the mixture of action mixture, and treating the addition prod xylenos and forming an addition product of 2,4- uct to produce the desired aromatic derivative dimethyl-6-tertiary-butylphenol with 2,4-xylenol, in substantially pure form. The product may be as hereinafter described, separating the addition 2,586,070 3 4. product from the remaining mixture, and treat therewith. After mixing the 2,4-dimethyl-6- ing the addition product under alkylating con tertiary-butylphenol with the mixture contain ditions with a butylating agent, thereby butylat ing 2,4-xylenol, the admixture preferably is heat ing the 2,4-xylenol content of the addition prod ed to above the melting point of the addition uct to obtain substantially pure 2,4-dimethyl product, in this instance to above about 46° C., 6-tertiary-butylphenol. Part of the product may and the mixture then cooled, or allowed to cool, be recycled to produce more addition product and whereupon a solid addition product separates, part taken as the final product. This process, which may be filtered or removed by any con which illustrates a preferred embodiment of the venient means. In some instances it is unneces present invention and which is more fully de 10 sary to heat the mixture, cooling being sufficient scribed hereinafter, provides a simple and eco to cause crystal formation, but it is generally nomical process for the production of aromatic preferable to first heat since the resulting crys derivatives from multi-component systems in tals may be more readily filterable. In general, cluding as a constituent thereof the aromatic the System consists of a homogeneous liquid phase compound to be treated, which process obviates until formation of the addition product com the objections to heretofore known methods, as mences. It is sometimes desirable to add a small above-described. quantity of seed crystals of the addition com The existence of addition products between pound to the mixture to aid crystal formation. different aromatic compounds, and between aros The presence of an inert liquid diluent may in matic compounds and other materials, such as 20 the addition products of phenol and alpha naph Somequent instancesseparation aid from crystal the formation system. andOf course,subse thylamine, phenol and para toluidine, and the materials may be heated before mixing, foll phenol and meta cresol has been recognized here lowed by mixing and cooling, as described. The tofore. Such compounds (i. e., compounds of separated addition product, consisting of 2,4- asSociation) or adducts may be considered as 25 dimethyl-6-tertiary-butylphenol and 2,4-xylenol, products of physical association between mole may then be butylated to produce essentially pure cules, as contrasted to the compounds formed 2,4-dimethyl-6- tertiary - butylphenol. Butyla by chemical reaction wherein the identities of the tion may be accomplished by any convenient reactants are lost in the formation of the new means, such as by melting the addition product product. Such addition products, however, have 30 and reacting with isobutylene preferably in the heretofore largely been considered merely as presence of a small amount of an alkylation laboratory curiosities, being prepared usually catalyst such as sulfuric acid, or by dissolving from the two pure components, or from simple the addition product in an inert solvent and mixtures, and their use restricted to simply the butylating. The product is essentially pure 2,4- separation of the addition product and recovery dimethyl-6-tertiary-butylphenol, and may be of the two components therefrom. divided, part being taken as the product and part In many instances, the formation and separa being recycled to form more addition product tion of addition products in accordance with the with 2,4-Xylenol. Similarly, 2,4-xylenol may be present invention provides new compositions of converted to a desired 2,4-dimethyl-6-alkyl matter which are useful and novel per se, but phenol by first forming an addition product the principal object of the invention, in addition thereof with a portion of such desired 2,4-di to the production and separation of addition methyl-6-alkyl-phenol, separating from other products, is the treatment or reaction of the ad dition products to form a desired derivative of materials, and then alkylating with an alkylating the aromatic component or components of the agent corresponding to the alkyl radical of said addition product. This procedure, as provided desired 2,4-dimethyl-6-alkyl-phenol.