US1870858A - Method for the production of ethylene glycols and ethylene hydrocarbons - Google Patents

Description

.. No Drawing. Original application filed May 18, 1926, Seria1 No. 109,961, now Patent No. 1,752,0l6, dated March 25, 1930.v Divided and this application filed. October 16,- 1929. seriai'umeooaoi latentecl Aug. 9, 1932 res v PATENT" OFFNJE;

ALEXANDER T. MAXIMOIF, or "vnnonnnr, ITALY, ASSIGNOR TO Eli-IE neuea'rucx CHEMICAL COMPANY; v NECTICUT OF NAUG-ATUGK, CONNECTICUT, A CORPORATION OF CON?- M THOD FOR THE PRODUCTION or ETVHYLENE eLYooLs Ann ETI-IYLENE :ezrnnocannoivs I l This case is a division of my application Serial No. 109,961, filed May 18, 1926, now Patent No. 1,7 52,016, issued March 25, 1930.

The present invention relates to the production of homologues of ethylene glycol and ethylene hydrocarbons, and to the production of pinacone from acetone. More particularly the invention relates to the activation of an aluminum reagent by the formation of a thin'layer of an active amalgam upon the surface of the aluminum.-

The ordinary method of amalgamating aluminum for use in the reduction of organic num activated by th usual methods.

compounds does not impart to it suflicierit' activity. According to the present invention the introduction of a third metal into the amalgam greatly increases the activity therereactions which are impossible with -alumi The metal introduced into the ordinary aluminum-mercury amalgam is preferably zinc.

b Other metals, such; as cadmium may also be employed. While the invention is not limited to any particular method of forming the reagent, the following may serve asillustrations. The amalgam may be conducted by the use of soluble salts ofmercury and of the third metal, these salts being precipitated upon aluminum which is immersed or suspended in the solution of these salts. Another 'method of forming the amalgam of this invention is to melt the aluminum and third metal together thus forming an alloy which may then be ground to any desired degree and subsequently amalgamated on its surface by treatment with the mercury salts.

lVhen acetone and other ketones and derivatives thereof are treated with the improved reagent it will be found that the nature of the reaction is dependent upon the amount of third metal present in the amalgam.

hen ketones are treated with aluminum,

num glycolates according to the following general reaction If the glycolate thus ob'tained be treated With water, a' glycol and aluminum hydroxide are obtained: l

lVhen acetone is treated with the improved reagent the end product will-be ethylenevglycol or pinacol. v 1

If the amount of third metal be increased to from 7 to 30% by weight of the aluminum,

ethylene hydrocarbons are produced when ketones are treated. For example acetone will yield propylene: i 3CH ;CO.CH +2Al= l v v The above equations describe reactions which take place in a non-aqueousmedium.- If'water be introduced into the reacting mi); ture, nascent hydrogen is evolved. This tetr amethyl' nascent hydrogen will lead to the formation of a series of reduction products; Under such conditions ketones will produce secondaryalcohols ornooern+an;ornxnaor-rcnn The improved activated aluminum reagent may be prepared by amalgamating an alloy of aluminum and another metal,.preferably zinc. In this instance the amalgam is prepared-according to the standard practiceof forming mercury amalgams of metals.

Afmalgams made with mercury and purealuminum are subject tothe disadvantagevv that the layer of amalgam is rather easily de-. tached during the reaction and frequently the reaction stops as the result of this. With T 1 zinc present in the amalgam layer a viscous tacky material is formed in which, the zinc may act as a cementing substance to keep the aluminum and mercury together. By increasing the percentage of zinc, say up to in the aluminum zinc alloy, a large percentage of propylene will appear in the reaction when acetone is used as the starting material. Vhen an alloy contains 7%01 zinc, propylene continues to appear in large quantities in this reaction. When the amount of zinc is reduced to 2% or less, very little propylene will appear, and pinacone is obtained as the main product. a

The same results may be obtained by'using mixtures of zinc and mercuric salts with aluminum inthe preparation of the amalgam.

For instance if amalgamation of the aluminum 'is carried out by using a solution of 5% oflzinc chloride and 10% mercuric chloride,

the treatment of acetone with such amalgamated aluminum. yields pinacone in large quantities, and relatively free; from propylene and other products. I

The advantage gained by the present invention is that any kind ofaluminum may be employed, and thealuminum may be used .in the form of filings or even in the iform of rough shavings. Moreover it has been the experience of organic chemists that not all makes of pure aluminum may be employed in carrying out these catalytic reactions. Indeed it is the general experience that there is but one kind of aluminum a product made in Germany which'will yield pinacone as the product of the reaction of acetone. By practicing the present invention, however, any kind of aluminum may beemployed and even better results obtained than with the above mentioned foreign product. The percent-age of zinc present in the alloy may be varied withinwide limits, depending upon the product desired. For the production of pinacone the percentage of zinc is figured to metallic zinc. If a zinc compound is employed, calculations' are made accordingly. For example serve as illustrations of some of the uses to which the improved aluminum amalgam may be put. It will be understood, however that the reagent may be variously employed in reduction reactions in the presence of water, as well as in reactions where the aluminum forms a compound with all or part of the reacting material. The claims are therefore to. be interpreted broadly. The expres sions metallic element, metal and zinc as used in the claims, are descriptive of these materials as single elements, or where, they are available as such for the purpose of the invention, and the percentages given in'the claims refer to percentages of the metal, not

ofits salt. It is to be understood therefore that salts of zinc and the other metals which may beemployed are comprehended by the claims.

Having thus described my invention, what I claim and desire to ent' is: r

In the production of ethylene glycols from ketones, the step of treating said ketones protect by Letters Patwith an aluminum amalgam containing" a small percentage of a metallic element selectedfrom the. group consisting of zinc and cadmium.

2. In the production of pinacone from acetone, the step of treating said acetone with an aluminum amalgam containing not more than approximately 3% of a third metallic element selected from the group consistin of zinc and cadmium.

a 8. n the production of pinacone from acetone, the step of treating said acetone with an aluminum amalgam containing not more than approximately 3% of zinc, said zinc having the properties of increasing the reactivity of the amalgam, and holding the components of the amalgam together.

Signed at Milan, Italy, this 27th day of September, 1929.

ALEXANDER T. MAXIMOFF.

zinc chloride: will analyze a little less than possessesthe advantage thatanytype of aluminum can be employed and that it is not