US2033548A - Mixed furyl-alkyl ketones - Google Patents

Description

Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE MIXED FURYL-ALKYL KETONES Anderson W. Ralston and Carl W. Christensen,

Chi Ill., assignors to Armour and Company, Chicago, 111., a corporation of Illinois 4 Claims.

This invention relates to mixed ketones and it comprises, .as new compounds, ketones having the generic structure n-o-rr ll wherein R is a furyl radical and R, is an alkyl radical having five or more carbon atoms.

The higher fatty acids, and by that we mean those fatty acids derived from vegetable and .animal oils and fats are extremely abundant materials and can be obtained at little expense. They have never, however, been used to any great extent as raw materials for the synthesis of more valuable substances. These fatty acids have been used almost exclusively in the soap industry, for making candles, etc, and in but relatively few instances have they been used as raw materials in what might be termed the fine organic chemical field.

We have now discovered a new class of compounds which can be made from the higher fatty acids and which have chemical and physical "properties of marked technical and commercial interest. We have discovered that the higher fatty acid chlorides, such as stearyl chloride, myristyl chloride, lauryl chlorides, caproyl chloride and other acid chlorides derived from, and corresponding to the higher fatty acids, can be made to react with furane, or substituted furanes, to give mixed ketones having valuable properties which suit them for use in many technical applications. Many of these mixed ketones are waxy solids and can be crystallized from organic solvents such as benzene, alcohol and others, to give pure ketones. The crystalline products, when melted and allowed to cool, yield substances of clearly defined waxy character, appearance and feel. Others are very high boiling liquids. We have discovered that they are excellent dielectrics and can be used in electrical insulation. We have also discovered that these new substances are desirable constituents in waxing .and polishing compounds. When added to lubricating oils, the ketones of the present invention confer beneficial properties on the oil.

In its broad aspects, our invention comprises new products having the generic formula wherein R is a furyl radical which may be substituted or not, and R is an alkyl radical containing the alkyl residue of a higher fatty acid.

Thus, as an example, one of the new products falling within the scope of our invention is furyl heptadecyl ketone, which can be written structurally as follows:

)CC17 a5 I0 In this case the Cl'7H35, or heptadecyl radical, is the alkyl residue of stearic acid, CriHssCOOH. 10 This particular ketone has a melting point of 525-54" C.

Other typical ketones falling within the scope of our invention are: furyl undecyl ketone, boiling at -167 C. at 5 mm. pressure, and methyl furyl heptadecyl ketone melting at (SS-69 C. and having the formula:

ore-i 0 i ofl11., 20

The dibenzofuryl compounds are especially interesting and valuable materials. Dibenzofuryl heptadecyl ketone melts at 83-84" C. and 25 has the formula:

CC11Ha5 30 o a;

The corresponding undecyl compound melts .at 74-75 C.

All of the ketones of our invention can be made by the Friedel-Craits reaction or by the Grignard synthesis. We find that the Friedel-Craits gives high yields.

Thus, for example, when we wish to make dibenzofuryl heptadecyl ketone, we start with. 40 dibenzofurane and stearyl chloride. The stearyl chloride can be made in any of the known ways from stearic acid. Generally the stearic acid is reacted with phosphorous pentachloride or other chlorinating agent commonly used for converting aliphatic carboxylic acids to their corresponding acid chlorides. We then prepare a mixture containing about 29 parts by weight of stearyl chloride, 16 parts by weight of dibenzoiurane and about 200 parts by weight of carbon disul- 50 phide. This mixture is cooled in an ice bath and about 26 parts of aluminum chloride (dry) are slowly added with stirring until there is no further evolution of hydrochloric acid. The reaction mixture is then poured into a mixture of 55 ice and dilute hydrochloric acid to hydrolyze the complex aluminum compound formed in the reaction. Finally the resulting acid mixture is placed in a flask and subjected to steam distillation. This removes carbon disulphide and any excess of dibenzofurane. During the steam distillation, the dibenzofuryl heptadecyl ketone separates from the aqueous reaction mixture in the distillation flask as an oily supernatant liquid. It does not distil over with the carbon disulphide and can be separated from the aqueous solution of aluminum chloride in the distilling flask by simple decantation. It is then taken up in acetone, carbon tetrachloride or other organic solvent and crystallized therefrom.

In a similar manner we can start with furane, alkyl-substituted furanes and other substitution products. Likewise, as stated, we can start with any acid chloride of the higher fatty acids. Generally we start with the acid chlorides of fatty acids having twelve or more carbon atoms since these fatty acids are readily available and cheap. Our invention is therefore not limited to the specific compounds described above, since we are the first to describe mixed ketones in which one radical attached to carbonyl is a furyl radical.

wherein R is a dibenzofuryl radical and R is an alkyl radical having at least 5 carbon atoms.

2. Mixed ketones having the structural formula R$|l-R wherein R is a dibenzofuryl radical and R. is an alkyl radical having at least 11 carbon atoms.

3. A dibenzofuryl heptadecyl ketone.

4. A dibenzofuryl undecyl ketone.

ANDERSON W. RALSTON. CARL W. CHRISTENSEN.