US3278614A - Production of primary straight chain alkyl halides - Google Patents

Description

United States Patent 3,278,614 PRODUCTION OF PRIMARY STRAIGHT CHAIN ALKYL HALIDES Pierre P. H. J. F. Michel, Biviers-Isere, France, assignor, by mesne assignments, to Jadwiga Z. Kubik, Rome, Italy No Drawing. Filed Oct. 24, 1963, Ser. No. 318,486 Claims. (Cl. 260-658) This application is a continuation-in-part of the co-pending application Serial No. 221,441, filed September 5, 1962, now abandoned, entitled Production of Primary Straight Chain Alkyl Halides. The entire disclosure of this co-pending application is incorporated herein by reference.

This invention pertains to the production of primary straight chain alkyl halides.

The production of primary straight chain alkyl halides is of importance at the present time because of certain problems in the field of synthetic detergents. These detergents have commonly been referred to as syndets; they are being used in greater and greater quantities. As their use increases, various problems caused by them become more and more serious. To a certain extent these syndets tend to cause corrosion of equipment and piping. They are well known to interfere with the operation of conventional types of sewage disposal systems. Frequently, these syndets lead to the presence of foams on various bodies of water where sewage effluents are discharged. In addition, more and more concern is being displayed as to the effect of these syndets on the ever present problem of obtaining portable water supplies.

It is known that synthetic detergents can be manufactured from straight chain aliphatic alcohols and/ or various straight chain alkylbenzenes, and that detergents formed from such compounds are capable of biochemical deterioration in conventional sewage systems and hence do not lead to various problems in sewage plant operation, in sewage efiluent foaming and in maintaining satisfactory water supplies as are briefly indicated in the preceding. Thus, various synthetic detergents based upon straight chain alkyl alcohols or alkylben zenes are capable of being decomposed by action of the type achieved in common trickling filter, activated sludge and other sewage disposal systems. It is believed that they are also capable of being decomposed under naturally occurring conditions through bacteriological and other action. Unfortunately, the use of straight chain aliphatic alkyl halides in synthetic detergents has been limited by the relative availability of these compounds at a competitive cost. This is because any synthetic detergent to be acceptable in the present commercial market must be priced at a comparatively nominal cost.

The present invention has for one of its objectives the production of various straight chain alkyl halides from compounds of the type X(CH CX in which X is a halogen atom. Compounds falling within the range of this structural formula can be easily and conveniently manufactured at a comparatively nominal cost at the present time. A closely related objective is to provide a process for the production of intermediate compounds of this type which can be carried out at a comparatively nominal cost without any significant or unusual production problems utilizing conventional type chemical equipment.

By way of summary it can be indicated that the present invention is primarily concerned with the hydrogenation of compounds of the type X(CH CX in which X is a halogen so as to replace the halide atoms in the terminal trihalomethane group with hydrogen without placing the halogen atom at the other end of the linear aliphatic molecule. Such hydrogenation can be carried out using a conventional hydrogenation catalyst such as nickel, plati- "ice num or palladium or halides or oxides thereof. The effectiveness of these catalysts can be increased by various expedients known to the field of chemistry. This hydrogenation should preferably be carried out in the absence of air.

Compounds falling within the preceding structural formula can be formed at a comparatively nominal cost by the telomerization of ethylene in the presence of a carbon tetrahalide such as carbon tetrachloride. The telomerization of ethylene to produce these compounds is well known at the present time and is described in the text, Telomerization and New Synthetic Materials, Freidlina et al., Pergamon Press, New York, N.Y. (1961). By appropriate variation in reaction conditions and in the relative quantities of the reaction ingredients supplied the length of the linear aliphatic chain of compounds falling within the structural formula as shown by the value of n in this formula can be varied over comparatively wide limits.

It is presently considered that in practising the present invention It should fall within the range of from 4 to 24 inclusive, since with shorter chain molecules it is not believed to be possible to manufacture satisfactory synthetic detergents, and since with longer chain molecules various solubility problems effectively preclude the formation of a desired type of synthetic detergents.

The catalysts used with the present invention are convention hydrogenation catalysts. Because of this it is not considered necessary to set forth in this specification a detailed description of these catalysts and of various factors concerning them. A catalyst used in carrying out this invention should, of course, be used in such a form as to provide as much surface area as is reasonably possible in order to promote catalyst activity. Thus, for example, a nickel catalyst used in carrying out the present invention may conveniently take the form of conventional Raney or extremely finely divided nickel. Platinum and palladium should, of course, be used in a similar form. These metals can all be disposed on an inert matrix.

It is not normally preferred to utilize as catalysts oxides of platinum and palladium, although if desired they can be used. It is acceptable to use with this invention a nickel oxide catalyst of a conventional variety. The various halides of the metals nickel, platinum and palladium such as the dichlorides of these metals or the tetrachlorides of platinum and palladium can be employed in practising this invention. In general, other halides such as the corresponding bromides, fluorides and iodides are not used in practicing this invention because of the availability considerations.

In practicing the present invention, a compound falling within the preceding structural formula is charged into a conventional autoclave formed of an inert material with a restricted amount of an inert solvent. Suitable solvents are saturated hydrocarbon such as cyclohexane, trimethylpentane and the like. In general, preferred results are obtained by charging the autoclave with from 0.1 by 10 parts by weight of solvent per part by weight of a compound falling within the preceding structural formula. The amount of catalyst used will of course depend upon the effectiveness of the particular catalyst employed. Acceptable results are generally obtained by using from about 0.1 to about 15 parts by weight of a catalyst as described in the preceding per part by weight of a compound falling within the preceding structural formula.

The reaction conditions employed in carrying out the process of this invention are of the general type usually employed in hydrogenation. With the present invention temperatures of from 50 C. to 250 C. can be satisfactorily employed. In general, the higher the temperature used the more rapid the reaction. The temperature used during the hydrogenation should, of course, be below the temperature at which any of the compounds present in the reaction vessel tend to decompose. If the temperatures below the lower value given in this range are used the reaction is too slow for practical purposes.

The pressure within the autoclave used for hydrogenation also influences the replacement of the halide atoms on the trihalidemethyl group. In general, pressures from about 0.1 to about 150 kilograms per square centimeter can be employed. At lower pressures the desired hydrogenation reaction without the replacement of the terminal halide atoms does not occur rapidly enough for commercial purposes while pressures falling above this range tend to make it diflicult to carry out the desired reaction and tend to promote undesired reactions within the vessel employed during the hydrogenation.

A surprising factor which is considered to be the basis of the present invention lies in the selectivity of the hydrogenation reaction carried out. When a hydrogenation reaction is carried out as set forth in the preceding, the single terminal halide atom in the starting compound is not replaced by hydrogen, whereas the halide atoms on the trihalomethyl group at the end of such a compound are completely replaced by hydrogen. Normally, it would be expected that such selective hydrogenation would not occur in practicing the present invention since hydrogenation is not a selective type of process.

The following specific examples are given as an aid to understanding this invention. From a careful consideration of these examples it will be realized that this invention can be practiced in other manners than are specifically set forth in them.

Example 1 A mixture of compounds having a structural formula Cl(CH CCl in which n has a value of from 6 to 16 in the amount of 350 grams per weight was charged into a stainless steel autoclave together with 6 grams of a conventional palladium or carbon matrix hydrogenation catalyst and 100 grams of trimethylpentane. Hydrogen was then bubbled through the reaction vessel in order to remove any traces of air; thereafter the reaction vessel was closed and raised to the temperature of about 100 to 110 C. This temperature was maintained throughout the reaction by means external to the autoclave. Hydrogen was then bubbled through the reaction vessel at the rate of about 25 liters per hour while the pressure in the vessel was maintained about 100 lbs. per sq. inch. After approximately 220 mins. the evolution of hydrogen chloride ceased. The reaction vessel was then cooled. A primary straight chain alkyl halide mixture was then recovered by filtration and distillation.

Example 2 The procedure set forth in Example 1 was followed using a mixture of 350 grams of a mixture of compounds having a structural formula as indicated in Example 1 in which It had a value of from 4 to 24, and in which the autoclave was charged with 35 grams cyclohexane solvent 4 and 35 grams of the catalyst specified in Example 1. A pressure of 150 kilograms per square centimeter was used while the temperature was maintained at 50 C.

Example 3 The procedure set forth in the preceding Example 1 was followed locating within the autoclave 3,500 grams cyclohexane, 525 grams Raney nickel. The reaction in the autoclave was carried out at a pressure of kilograms per square centimeter at a temperature of 250 C.

It is to be understood that instead of the chlorides specified in the preceding examples other corresponding halogen compounds such as the bromides, fluorides and iodides could be used.

I claim:

1. A process for producing a primary straight chain alkyl chloride from a compound having the formula Cl(CH CCl where n is an integer having a value of from 4 to 25, which comprises:

passing hydrogen in contact with a mixture of at least one compound having said formula, a hydrogenation catalyst and in inert saturated hydrocarbon solvent while maintaining said mixture at a temperature of from 50 to 250 C. and while maintaining said mixture under a pressure of from 0.1 to kilograms per square centimeter so as to cause the terminal -CCl group on said compound to react with said hydrogen, liberating hydrogen chloride and continuing passing hydrogen in contact with said mixture until the liberation of hydrogen chloride ceases.

2. A process as defined in claim 1 wherein said mixture contains from 0.1 to 10 parts per weight of solvent per part by weight of said compound.

3. A process as defined in claim 1 wherein said mixture contains from 0.1 to 15 parts per weight of said catalyst per part by weight of said compound.

4. A process as defined in claim 1 wherein said catalyst is selected from the group consisting of, nickel, platinum and palladium hydrogenation catalysts.

5. A process as defined in claim 1 wherein said solvent is cyclohexane.

References Cited by the Examiner UNITED STATES PATENTS 2,427,791 9/ 1947 Ipatieif et a1. 260-658 2,440,800 5/1948 Hanford et al. 260-658 2,644,835 7/1953 Ladd et al 260-658 X 2,651,664 9/1953 Ladd et al 260--658 2,658,929 11/1953 Ladd et al. 26065 2,886,605 5/1959 McClure et al. 260658 X OTHER REFERENCES Freidlina et al.: Telomerization and New Synthetic Materials, Pergamon Press (1961, pp. 1722).

LEON ZITVER, Primary Examiner.

K. V. ROCKEY, Assistant Examiner.