US2047396A - Synthetic production of alcohols - Google Patents

Description

Patented July 14, 1936 PATENT OFFICE SYNTHETIC PRODUCTION OF ALCOHOLS Ernst T. Theimer, Newark, N. 1., assignor to van Ameringen-Haebler, Inc., New York, N. Y., a corporation of New York 1 No Drawing. Application August 29, 1933, Serial No. 687,317

23 Claim.

This invention. relates to the synthetic production of. alcohols. It is particularly concerned with an improvement in that process of producing alcohols in which the formation of alcohols is brought about by the condensation of alkylene oxides, or substances which are capable of forming alkylene oxides, with hydrocarbons or substituted hydrocarbons in the presence of anhydrous metal halides.

The present application is a continuation in part of myco-pending application Serial No. 645,-

753, filed December 5, 1932, for Manufacture of aromatic alcohols.

In the prior art, the process above referred to was carried out by the direct addition of the alkylene oxide to the suspension of metal halide in the hydrocarbon. As thus carried out, the process has a relatively low yield, the reason being that the alkylene oxide comes into contact with the metal halide in a concentrated state so that it reacts with itself, forming undesirable byproducts rather than with the hydrocarbon, form ing the desired alcohol. According to the present invention, this disadvantage is overcome by forming a more or less dilute solution of the alkylene oxide in the hydrocarbon or in an inert solvent and running this solution into a suspension of the metal halide in another quantity of the hydrocarbon or in a solution of the hydrocarbon in an inert solvent. The quantity of hydrocarbon used should be such that, when a molecule of alkylene oxide comes in contact with the metal halide, it is surrounded by a great number of molecules of the hydrocarbon, the latter being present in excess, so that it is disposed to react with these molecules rather than with another molecule of itself. The yield of the alcohol, therefore, is much higher as compared to the yield in the above described processes of the prior art.

The greater the excess of hydrocarbon in the solvent used both for dissolving the ethylene oxide and for suspending the aluminum chloride, the higher the yield will be.

Suitable hydrocarbons are any of the paraflin hydrocarbon series, for example, hexane, heptane, dodecane, octadecane, etc. Also, the cyclo-paraflins, for instance, cyclopentane and cyclohexane. Then the aromatic hydrocarbons, such, as, benzol, toluol, cymene, naphthalene, etc, and also any of these hydrocarbons which have substituted chlorine or bromine atoms, for instance,

. monochlor benzene or monobrom benzene, or the like. Any mixtures'of these hydrocarbons may be used just as well. They may occur naturally,

or may be mixed artificially. For instance, gasoline or petroleum fractions or coal tar products, etc. may be used. Heterocyclic compounds such as pyridine, quinoline or thiophene may be used also. Nitro derivatives, ethers and esters of the aromatic hydrocarbons are also suitable. It will be noted that all the materials specified in this paragraph are materials capable of undergoing a Fricdel-Crafts condensation with an alkylene oxide or substance capable of forming such oxide. .In the appended claims these materials will be referred to generally as Friedal-Crafts reactants.

Examples of the alklyene oxides are ethylene oxide, trimethylene oxide, propylene oxide, isobutylene oxide and'the like. Substances which form alkaline oxides by elimination of hydrochloric or hydrobromic acid, as, for example, ethylene chlorhydrin and propylene bromhydrin, may also be used. The term alkylene oxide is used in the appended claims is intended to include both alphylene oxides and aryline oxides in accordance with the Geneva nomenclature, and is intended also to include substances, as specified above, capable of forming such oxides.

Examples of metal halides which may be used are anhydrous aluminum halides, such as aluminum chloride and aluminum bromide, anhydrous ferric chloride and boron fluoride.

The method of the present invention consists in bringing about a reaction of an alkylene oxide with a substantial excess of Friedel-Crafts reactant in the presence of an anhydrous metal halide. In case the Friedel-Crafts reactant is capable of dissolving the alkylene oxide the process is preferably/carried out by first forming the solution of the alkylene oxide in an excess of Friedel- Crafts reactant and then bringing about a reaction between this solution and a suspension of the metal halide, preferably in another quantity of the F'riedel-Crafts reactant. The temperature at which this reaction is caused to take place should be low enough to prevent as much as possible of the alcohol which is first formed from undergoing a secondary reaction, namely, of combining with another molecule of hydrocarbon and forming undesired hydrocarbons.

For example, for the synthetic production of betaphenyl ethyl alcohol the ethylene oxide or a substance capable of forming ethylene oxide,-

such as ethylene chlorhydrin or ethylene bromhydrin, is dissolved in dry benzol or a mixture of dry benzol and some inert solvent, such as petrolic ether, at a temperature low enough to prevent volatilization of the ethylene oxide (or thehydrocarbon solvent for that matter,) and this solution is caused to react with a suspension of metal halide in benzol or a mixture of benzol with some inert solvent, such as carbon bisulphide. at a temperature above the freezing point of the solvent mixture, and low enough to prevent the formation of appreciable amounts of dibenzyl. The lower temperature limit in the case of benzol alone as a solvent will obviously be the freezing point of benzol, which is about 3 to 6 C., depending upon the purity of the benzol. In the case of mixtures of benzol with inert solvents the lower temperature limit will depend on the freezing point of the mixture. Temperatures much above 60 C. will lead to. the formation of an appreciable amount of dibenzyl with a consequent lowering of the yield of betaphenyl ethyl alcohol.

A specific example of the synthetic production of betaphenyl ethyl alcohol according to the present method is as follows:

50 lbs. of anhydrous aluminum chloride are suspended in 120 lbs. of dried benzol. In another kettle, 16 lbs. of ethylene oxide are dissolved in 240 lbs. of dried benzol at a temperature between 5 and C. The ethylene oxide solution thus formed is then run into the suspension 0! aluminum chloride in benzol at a temperature of 6 to 10" (3., he mixture being stirred and kept at this temperature in any desired manner, as by cooling by brine circulation. After all the ethylene oxide solution has thus been added, the mass is stirred for an additional A hour and 400 lbs. of water are thereupon added, the temperature being kept between zero and 10 C. The water layer is then separated and the benzol layer is washed once with 50 lbs. of 2% sodium carbonate solution after which the benzol is recovered and the phenyl ethyl alcohol is vacuum distilled. In the above specific example it will be noted that a large excess of benzol over ethylene oxide has been used. While a still greater excess of benzol might be employed to produce a greater yield of phenyl-ethyl alcohol based on the amount of ethylene oxide used, the proportions above given have been found by me to be the most desirable for ordinary commercial purposes.

The process of the present invention as concerned with the synthetic production of hydratropyl alcohol is carried out in exactly the same manner as the above described process for the production of betaphenyl ethyl alcohol, except that propylene oxide is employed instead of ethyl-' ene oxide. Because of the higher molecular weight of propylene oxide, it will be necessary to use 21 lbs. of this in place of the 16 lbs. of ethylene oxide used in the previous example. I have described what I believe to be the best manner of practicing my invention. I do not wish, however, to be confined to the process as described, but what I desire to cover by Letters Patent is set forth in the appended claims.

The relative proportions of reagents used in the previous two examples will give a yield of about forty per cent of theory. The present invention may be applied to the production of 2-methyl, 5- isopropyl, hydratropyl alcohol by substituting dried distilled para-cymene for dried benzol, in the above example relating to the production ofhydratropyl alcohol.

Similarly, tolyl ethyl alcohol may be produced by substituting dried toluol for dried benzol in the process described in connection with beta-phenyl ethyl alcohol. Likewise, xylyl ethyl alcohol can be obtained by substituting ordinary commercial dried xylol for benzol in the example pertaining to the production of betaphenyl ethyl alcohol.

Similarly. by substituting dried monobrom benzene for benzol in the example relating to betaphenyl ethyl alcohol, a yield of about ten per cent 01 theory of brom phenyl ethyl alcohol is obtained.

It will be then seen that many other alcohols may be produced in accordance with the present invention, by carrying the same out with other combinations of hydrocarbons and alkeylene oxides.

I have described what I believe to be the best manner of carrying out my invention. I do not wish, however, to be confined to the examples given, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. The process for the synthetic production of alcohols, which consists in forming a solution of an alkylene oxide in a Friedel-Craits reactant forming a suspension of an anhydrous metal halide in such reactant and causing said solution and suspension to react with each other.

2. The process for the synthetic production of alcohols, which consists in forming a solution of an alkylene oxide in a Friedel-Crafts reactant forming a suspension of an anhydrous metal halide in such reactant and causing said solution and suspension to react with each other at a temperature below that at which the alcohol first formed reacts with the Friedel-Crafts reactant present under the influence of the anhydrous metal halide.

3. The process for the synthetic production of betaphenyl ethyl alcohol, which consists in dissolving ethylene oxide in dry benzol, and causing this solution to react with a suspension of an anhydrous metal halide in dry benzol.

4. The process for the synthetic production of beta-phenyl ethyl alcohol, which consists in dissolving ethylene oxide in dry benzol, and causing this solution to react with a suspension of a metal halide in dry benzol at a temperature between approximately 5 C. and 60 C.

5. The process for the synthetic production of beta-phenyl ethyl alcohol, which consists in dissolving ethylene oxide in dry benzol, and causing this solution to react with a suspension of an anhydrous metal halide in dry benzol at a temperature below approximately 60 C.

6. The process for the synthetic production of hydratropyl alcohol which consists in dissolving propylene oxide in dry benzol, and causing this solution to react with a suspension of metal halide in dry benzol.

7. The process for the synthetic production of alcohols, which consists in bringing about a reaction of an alkylene oxide with a substantial excess of a'Friedel-Crafts reactant in the presence of an anhydrous metal halide, the molar ratio of Friedel-Crafts reactant to alkylene oxide being greater than approximately 10:1.

8. The process for the synthetic production of alcohols, which consists in forming a solution of alkylene oxide in a substantial excess of Friedel- Crafts reactant and then bringing about a reaction between this solution and a suspension of an anhydrous metal halide.

9. The process for the synthetic production of alcohols, which consists in forming a solution of alkylene oxide in a substantial excess of Friedel- Crafts reactant and then bringing about a reaction between this solution and a suspension of an anhydrous metal halide, in another quantity of the Friedel-Craits reactant.

10. The process for the synthetic production of 7 Crai'ts reactant to alkylene oxide being greater than approximately 10: 1.

12. The process for the synthetic'production of alcohols, which consists in bringing about a reaction of ethylene oxide with a substantial excess of a Friedel-Crafts reactant in the presence of an anhydrous metal halide, the molar ratio of Friedel-Crafts reactant to ethylene oxide being greater than approximately 10:1.

13. The process for the synthetic production of alcohols, which consists in bringing about a reaction of ethylene oxide with a substantial excess of aromatic hydrocarbon in the presence of an anhydrous metal halide, the molar ratio of Friedel-Crafts reactant to ethylene oxide being greater than approximately 10: 1.

14. The process for the synthetic production of betaphenyl ethyl alcohol, which consists in bringing about a reaction of ethylene oxide with a substantial excess of dry benzol in the presence of an anhydrous metal halide, the molar ratio 01' Friedel-Crafts reactant to ethylene oxide being greater than approximately 10: 1.

15. The process for the synthetic production of betaphenyl ethyl alcohol, which consists in bringing about a reaction of ethylene oxide with a substantial excess of dry benzol in the presence of an anhydrous aluminum chloride, the molar ratio of Friedel-Crafts reactant to ethylene oxide being greater than approximately 10:1.

16. The process for the synthetic production of betaphenyl ethyl alcohol, which consists in bringing about a reaction of ethylene oxide with a substantial excess of dry benzol in the presence of an anhydrous metal, halide at a temperature between approximately 5 C. and 0., the molar ratio of Friedel-Crafts reactant to ethylene oxide being greater than approximately 10:1.

17. The process for the synthetic production of betaphenyl ethyl alcohol, which consists in bringing about a reaction of ethylene oxide with a substantial excess of dry benzol in the presence or an anhydrous metal halide at a temperature of approximately 10 0., the molar ratio of Friedel-Crafts reactant to ethylene oxide being greater than approximately 10:1.

18. The process for the synthetic production of betaphenyl ethyl alcohol, which consists in bringing about a reaction of ethylene oxide with a substantial excess of dry benzol in the presence of anhydrous aluminum chloride at a temperature between approximately 5 C. and 60 C., the molar ratio of Friedel-Crafts reactant to ethylene oxide being greater than approximate- 19. The process for the synthetic production of betaphenyl ethyl alcohol, which consists in bringing about a reaction of ethylene oxide with a substantial excess of dry benzol in the presenceof anhydrous aluminum chloride at a temperature of. approximately 10 C., the molar ratio of Friedel-Crafts reactant to ethylene oxide being greater than approximately 10:1.

20. The process for the synthetic production of betaphenyl ethyl alcohol, which consists in bringing about a reaction of ethylene chlorhydrin with a substantialexcess of dry benzol in the presence of an anhydrous metal halide.

21. The process herein described comprising suspending anhydrous aluminum chloride in dried benzol, dissolving ethylene oxide in dried benzol at a temperaure of between 5 and 10 C., and running the ethylene oxide solution thus formed into the suspension of aluminum chloride in benzol at a temperature of between approximately 6 to 10 C.

22. The process herein described comprising suspending anhydrous aluminum chloride in dried benzol, dissolving ethylene oxide in dried benzol at a temperature of between 5 and 10 C., and running the ethylene oxide solution thus formed into the suspension of aluminum chloride in benzol at a temperature of between approximately 6 to 10 C. and adding water, holding the temperature of the mass at between 0 and-10 C. approximately.

23. The process herein described comprising suspending anhydrous aluminum halide in dried benzol, dissolving ethylene oxide in'dried benzol at a temperature of between approximately 5 and 10 C., and causing the ethylene oxide to react with the suspension of aluminum halide in benzol at a temperature sufflciently low that the predominant product of the reaction will be betaphenyl ethyl alcohol as distinguished from di-benzyl. ERNST T. THEIMER.