US3193475A - Coupling cyclic olefins by electrolysis - Google Patents

Description

United States Patent Ofiice 3,193,475 Patented July 6, 1965 3,193,475 CUUPLING CYCLIC OLEFINS BY ELECTROLYSIS Manuel M. Baizer, St. Louis, Mo., assignor to Monsanto Company, a corporation of Delaware No Drawing. Filed Aug. 13, 1962, Ser. No. 216,304 10 Claims. (Cl. 20473) This invention relates to the manufacture of polyfunctional compounds and more particularly provides a new electrolytic process for reductively coupling cycloalk-lenecarboxylates, -carbxamides, and cyanides.

An object of the invention is the provision of a'process for preparing 2,2'-biscycloalkanecarboxylates, -carboxamides and cyanides (or carbonitriles).

The reaction of the present invention can be illustrated as follows with cyclohexene as the cycloalkene:

in which X represents a carboxylate, carboxamido or cyano group. The reactants can also be termed 1-carboXylato-, l-carboxamidoor l-cyanocycloalk-l-enes. X can be further defined as representing -CN,

in which R represents hydrogen or hydrocarbon radicals, e.g., alkyl or aryl radicals and R represents hydrocarbon radicals, e.g., alkyl or aryl radicals, particularly such radicals containing no more than 8 carbon atoms.

Compounds suitable as reactants in the present invention are illustrated, for example, by the above formula, or similar formula for cyclopent-l-enes and cyclohept-lenes in which X can be cyano, carboxarnido, N,N-diethylcarboxamido, N-phenylcarboxamido, carbethoxy, carbhexoxy, carbphenoxy, etc. It will also be understood that the cycloalkene rings can have various substituents not reducible by electrolysis or of which the reduction does not lead to undesirable products, e.g., various alkyl substituents such as methyl, ethyl, propyl, isopropyl, the various propyl and butyl isomers, hexyl, etc., such as in 1-cyano-3-ethyl-cyclohexl-ene, 1-cyano-4-methyl-cyclohept-1-ene, l-cyano--butyl-cyclopentl-ene, l-carbethoXy-3isopropyl-cyclohex-l-ene, l-carboXamido-4-hexyl-cyclohexl-ene, 1-(N,N-diethylcarboxamido)-cyclohept-l-ene, etc.

In general, the electrolytic reductive coupling of the present invention is conducted in concentrated solution in an aqueous electrolyte. It is desirable to employ fairly concentrated solutions in order to minimize undesired reactions of intermediate ions with the water of the electrolyte. The olefinic reactants will ordinarily comprise at least about by weight of the electrolyte, and preferably at least 20% by weight or more. It is generally desirable to employ fairly high concentrations of salts in the electrolyte, for example constituting 5% and'usually 30% or more by weight of the total amount of salt and water in the electrolyte, in order to obtain the desired solubility of the olefinic compounds.

The hydrodimerization' of alpha,beta-olefinic carboxylates, nitriles and carboxamides is taught in my copending applications S.N. 145,480 and 145,482 filed October 16, 1961, both of which are now abandoned, and SN. 75,130 filed December 12, 1960, now forfeited, the disclosures of which are incorporated herein by reference; continuation-impart applications of the foregoing are SN.

333,647 filed December 26, 1963, SN. 337,540 filed January 14, 1964 and S.N. 337,546 filed January 14, 1964. The conditions taught in the referred to applications for hydrodimerization are suitable for hydrodimerizations or other reductive couplings of the present invention.

Electrolysis, of course, has been practiced for many years and numerous materials suitable as electrolytes are known, making it within the skill of those in the art in the light of the present disclosure to select electrolytes for reductive coupling according to the present invention. As discussed in my aforesaid copending applications, some olefinic compounds are subject to polymerization or other side reactions if the electrolyte is acidic, or excessively alkaline, and it will be necessary in such cases to conduct the reductive coupling in solutions which are not overly acidic and also in some cases below a pH at which undesirable side reactions occur, e.g., below about 12. In general, the olefinic compounds employed in the present invention are not readily polymerized, but the pH is usually maintained within the range of about 3 to about 12 to obtain desired yields, preferably pHs of 6 to 9.5.

When the catholyte during electrolysis is acidic, it will generally be advisable to conduct the electrolysis under conditions which inhibit polymerization of the reactants involved or in the presence of a polymerization inhibitor, for example, in an atmosphere containing sufficient oxygen to inhibit the polymerization in question, or in the presence of inhibitors effective for inhibiting free radical polymerization. Classes of inhibitors for inhibiting free radical polymerizations are well known, e.g., such inhibitors as hydrcquinone, p-t-butyl catechol, quinone, pnitroso dimethylaniline, di-t-butyl hydroquinone, 2,5-dihydroxy-1,4-benzoquinone, 1,4-naphthoquinone, chloranil, 9,10-phenanthraquinone, 4-amino-1-naphthol, etc., are suitable.

In effecting the reductive coupling of the present invention it is preferred to utilize a cathode having an overvoltage greater than that of copper and to subject to electrolysis in contact with such cathode a concentrated solution of the defined olefinic compounds in an aqueous electrolyte under mildly alkaline conditions. In effecting the reductive couplings of the present invention, it is essential to obtain cathode potentials required for such couplings and therefore the salt employed should not contain cations which are discharged at numerically lower, i.e., less negative, cathode potentials. It is desirable that the salt employed have a high degree of water solubility to permit use of very concentrated solutions, for concentrated salt solutions dissolve greater amounts of the organic olefinic compounds.

In addition to the foregoing considerations, a number of other factors are important in selecting salts suitable for good results. For example, it is undesirable that the salt cation form an insoluble hydroxide at the operating pH, or that it discharge on the cathode forming an alloy which substantially changes the hydrogen over-voltage and leads to poorer current efficiencies. The salt anion should not be lost by discharge at the anode with possible formation of by-products. If a cell containing a separating membrane is used, it is desirable to avoid types of anions which, in contact with hydrogen ions present in the anolyte chamber, would form insoluble acids and clog the pores of the membrane. Alternatively, the use of an ion exchange membrane eifectively separates catholyte and anolyte and the use of different anions in the two chambers may minimize any difficulties a particular anion would cause in one of the chambers.

In general amine and quaternary ammonium salts are suitable for use in the present process. Certain salts of alkali and alkaline earth metals can also be employed to some extent, although they are more subject to interfering discharge at the cathode and-the alkaline earth metal salts in general tend tohave poor watersolubility,

making their use' inadvisable.

The present invention is primarily concerned with re: ductive coupling of two molecules of: the same compound, 'i.e., with hydrodimerization.

boxamides and cyanides with other compounds, e.g., with other cycloalk-1-ene carboxylates, -carboxamides and cyanides or with other hydrodimerizable olefinic compounds, for example with the alpha, beta-olefinic carbox- A 'catholyte was prepared from 88.4 g. l-cyano-cyclohex-l-ene, 84.4 g. of a solution containing 76.5% by weight methyltriethylammonium p-toluenesulfonate and 81*.5 g. dimethyli'ormamide. As anolyte, the 76.5% toluenesulfonate solution was used in an Alundum cup. The

However, it also includes reductive couplings of cycloalk-l-ene carboxylates, .car-

. calcium. sulfate. The volatile material was stripped off and the remainder was distilled to recover 69 grams of starting monomer, leaving 6 grams of product, RP.

148/1.8 mm. to 150/1.6 mm., n 1.4939. The 2,2- bis-cyclopentanecarbonitrile analyzed as follows. Calcd:

.C, 76.60;.H, 8.50; N, 14.90. Found: C, 76.10; H, 8.41;

' N, 13.87. Vapor phase. chromatographic analysis showed anode was platinum and the cathode wasllO ml. merleave 19 g. of almost completely solid residue, which was worked with absolute alcohol and dried to a white solid, MP. 216-218 C. Analysis for 2,2'-bis(cycl-ohexane cyanide): Calcd: C, 77.73; H, 9.37; N,'12.96.' Found: C, 77.16; H, 9.28; N 12.95.

Example 2 V a As catholyte a solution was employed prepared from 80 grams of 89.5% methyltributylammonium.p-toluenesulfonate in water, 80 grams of l-carbethoxycyclohex-l-ene and 10 ml. acetonitrile. The anolyte was'12 ml. of the toluenesulfonate solution diluted with 12 ml. water. Electrolysis was conducted for about four hours at a cathode voltage of -2.05 to -2.l0 volts (vs. saturated calomel electrode), fora total of about 6.6 ampere hours. The catholyte was extracted with methylene'dichloride, and the extracts washed with water and dried over calcium sulfate. Volatile material was removed by distillation and the residual liquid was extracted with ether, washed with water and dried over calcium sulfate. The ether was removed by'warming on a water bath, to leave 73 grams of pale yellow residue. Upon fractional distillation the pale yellow 2,2-dicarbethoxydicyclohexyl was collected at 134-142" C./0.3 mm., 11 1.4739 Analysis.Calcd: C, 69.64; H, 9.74. Found: C, 69.77; H, 9.53.

Example 3 A catholyte was prepared from 82 grams of l-cyanocyclopent-l-ene, 81 grams of an 80% solution of tetra-- ethylammonium p-toluenesulfonate in water, and 70. As anolyte in the divided cell, 20

During two peaks, indicating the presence of two steroisomers.

The above examples are illustrative of the present process and the reductive couplings of the-various other olefinic reactants described herein can be conducted under the, same conditions or numerous variations thereof. ,In addition, the procedures of the various examples of my aforesaid copending applications S.N. 145,480 'and 145,482 are applicable to the hydroimerizations of the olefinic reactants described herein. 7

The electrolyte re-du-ctive'couplings of the present invention are conducted in solution in electrolyte, generally in fairly concentrated solution in an aqueous electrolyte. It will be recognized that asused herein an electrolyte is considered aqueous even if .the amount of water issmall;

Many electrolytes can be employed in the present invensolution, such as solutions of mineral'acidsand it is desirable or necessary in such cases to avoid exoessiveacidity, making it desirable to operate at pHs above about 5 or 6, such as provided by solutions of salts of strong bases.

' Moreover, the hydrogen ion has a cathode discharge poin the catholyte.

tential of about '1.5 volts, making'it desirable to avoid high concentrations ofthydrogen ionin the ca-tholyte if the reductivecoupuling occurs at similar or more negative cathode potentials. The reductive couplings can suitably be conducted at pHs higher than those at which substantial polymerizaton of olefinic compound occurs, or higher than those at which there is undue generation of hydrogen, for example pHs at which more than half the current is expended in discharging hydrogen ions. The pHs referred to are those obtaining in the bulk of the catholyte solution, such as determinable by a pH meter on a sample of the catholyte removed from the cell. The electrolysis in effect generates. acid at the anode and base at the cathode; it will be recognized that in an undivided cell the pH in the immediate vicinity of the cathode may differ considerably from that near the anode, particularly if good stirring is not employed. To some extent the effects of acidity can be counteracted by high current density to cause more rapid generation of hydroxyl ions. Howevery, high current densities also require good stirring or tubulence to move the reactants to the cathode.

During electrolysis in a divided cell, alkalinity increases However, the anolyte becomes acidic- When a porous diaphragm is used to separate the catholyte from the anolyte, the alkalinity of the catholyte will over a period of an hour as some hydrogen evolved, in-

dicating development of acidity from impurities in'the 7 through the porous'barrier.

depend upon the'rate'of difiusionof acid from the anolyte Control of alkalinity in the catholyte when employing a diaphragm, may thus be realized by purposely leaking acid fromthe anoly-te into the catholyte. It can also be achieved, of. course, by extrarieous addition to the catholyteof an acid material, e.g., glacial. acetic acid, phosphorie acid for p-toluenesulfonic acid. Alkalinity may also be controlled, whether or not a diaphragm is used in the cell, by employing buffer systems of cations which will maintain the pH range while not reacting at the reaction conditions.

When the olefinic compounds include a carboxylate, the pH of the catholyte solution should not be allowed to rise to the point where substantial hydrolysis of the ester occurs. Since the lower alkyl esters, i.e., the methyl or ethyl esters are usually more readily hydrolyzed than the higher alkyl esters, the optimum pH will vary with the nature of the ester. When the desired reaction involves a reductive coupling with acrylonitrile, it will be desirable to maintain the pH sufficiently low to avoid or substantially minimize cyano-ethylation for example substantially below 9.5. Otherwise, substantial quantities of bis(betacyan-oethyl)ether are obtained. Similarly, when other olefinic nitriles are employed, it will be necessary to maintain the pH low enough to substantially minimize addition of water to the double bond. Good agitation or turbulence may counteract excess alkalinity to some extent by minimizing local concentrations of hydroxyl ions at the cathode.

When a divided cell is employed, it will often be desirable to use an acid as the anolyte, any acid being suitable, particularly :dilute mineral acids such as sulfuric o1 phosphoric acid. Hydrochloric acid can be employed but would have the disadvantage of generating chlorine at the anode, and of being more corrosive with respect to some anode materials. When an acid is employed as anolyte, it is advantageous to use an ion exchange membrane to separate the anolyte from the catholyte. If desired, a salt solution can be used as anolyte, those useful as catholyte also being suitable as anolyte, although there are many other salt solutions suitable for such use.

Materials suitable for constructing the electrolysis cell employed in the present process are well known to those skilled in the art. The electrodes can be of any suitable cathode and anode material. The anode may be of virt-ually any conductor, although it will usually be advantageous to employ those that are relatively inert or attacked -or corroded only slowly by the electrolytes; suitable anodes are, for example, platinum, carbon, gold, nickel, nickel silicide Duriron, lead and lead-antimony and lead-copper alloys, and alloys of various of the foregoing and other metals.

Any suitable material can be employed as cathode, various metals and alloys being known to the art. It is generally advantageous to employ metals of fairly high hydrogen overvoltage in order to promote current efiiciency and minimize generation of hydrogen during the electrolysis. In general it will be desirable to employ cathodes having overvoltages at least about as great as that of copper, as determined in a 2 N sulfuric acid solution at current density of 1 milliamp./ square centimeter (Carman, Chemical Constitution and Properties of Engineering Materials, Edward Arnold and Co., London, 1949, page 290). Suitable electr-ode materials include, for example, mercury, cadmium, tin, zinc, bismuth, lead, graphite, aluminum, nickel, etc., in general those of higher overvoltage being preferred. It will be realized that overvoltage can vary with the type of surface and prior history of the metal as well as with other factors; therefore the term overvoltage as used herein with respect to copper as a gauge has reference to the overvoltage under the conditions of use in electrolysis.

Among the salts which can be employed according to the present invention for obtaining the desired concentration of dissolved olefinic compound the amine and quaternary ammonium salts are generally suitable, especially those of sulfonic and alkyl sulfuric acids.

Such salts can be the saturated aliphatic amine salts or hcterocyclic amine salts, e.g., the mono-dior trialkylamine salts, or the mono-, dior trialkanolamine salts, or the piperidine, pyrrolidine, or morpholine salts, e.g., the ethylamine, dimethylamine or triisopropylamine salts of various acids, especially various sulfonic acids. Especially preferred are aliphatic and heterocyclic quaternary ammonium salts, i.e., the tetraalkylammonium or the tetraalkanolammonium salts or mixed alkyl alkanol ammonium salts such as the alkyltrialkanolammonium, the dialkyldialkanolammonium, the alkanoltrialkylammonium or the N- heterocyclic N-alkyl ammonium salts of sulfonic or other suitable acids. The saturated aliphatic or heterocyclic quaternary ammonium cations in general have suitably high cathode discharge potentials for use in the present invention and readily form salts having suitably high water solubility with anions suitable for use in the electrolytes employed in the present invention. The saturated, aliphatic or heterocyclic quaternary ammonium salts are therefore in general well adapted to dissolving high amounts of olefinic compounds in their aqueous solutions and to eifecting reductive couplings of such olefinic compounds. It is understood, of course, that it is undesirable that the ammonium groups contain any reactive groups which might interfere to some extent with the reductive coupling reaction. In this connection it should be noted that aromatic unsaturation as such does not interfere as benzyl substituted ammonium cations can be employed; (as also can aryl sulfonate anions).

Among the anions useful in the electrolytes, the aryl and alkaryl sulfonic acids are especially suitable, for example, salts of the following acids: benzenesulfonic acid, o-, mor p-toluenesulfonic acid, o-, mor p-ethylbenzenesulfonic acid, o-, mor p-cumenesulfonic acid, 0-, mor ptert-amylbenzenesulfonic acid, o-, mor p-hexylbenzenesulfonic acid, o-, xylene-4-sulfonic acid, p-xylene-Z-sulfonic acid, m-xylene-4 or 5-sulfonic acid, mesitylene- 2-sulfonic acid, durene-3-sulfonic acid, pentamethylbenzenesulfonic acid, o-dipropylbenzene 4 sulfonic acid, alphaor beta-naphthalenesulfonic acid, o-, m-, or pbiphenylsulfonic acid, and alpha-methyl beta naphthalenesulfonic acid. Alkali metal salts are useful in the present invention with certain limitations, and the alkali metal salts of such sulfonic acids can be employed, i.e., the sodium, potassium, lithium, cesium or rubidium salts such as sodium benzenesulfonate, potassium p-toluenesullfonate. lithium o-biphenylsulfonate, rubidium betanaphthalenesulfonate, cesium p-ethylbenzensulfonate, sodium o-xylene-3-sulfonate, or potassium pentamethylbenzenesulfonate. The salts of such sulfonic acids may also be the saturated, aliphatic amine or heterocyclic amine salts, e.g., the mono-, dior trialkyl-amine salts, or the mono-, dior trialkanolamine salts, or the piperidine, pyrrolidine or morpholine salts, e.g., the ethylamine, dimethylamine or triisopropylamine salt of benzenesulfonic acid or of o-, por m-toluenesulfonic acid; the isopropanolamine, dibutanolamine or triethanolamine salt of o-, por m-toluenesulfonic acid or of o-, por m-biphenylsulfonic acid; the piperidine salt of alphaor beta-naphthalenesulfonic acid or of the cumenesulfonic acids; the pyrrolidine salt of o-, m-, p-amylbenzenesulfonate; the morpholine salt of benzenesulfonic acid, of o-, mor p-t-oluenesulfonic acid, or of alphaor beta-naphthalenesulfonic acid, etc. In general, the sulfonates of any of the ammonium cations disclosed generically or specifically herein can be employed in the present invention. The allphatic sulfonates are prepared by reaction of the correspondingly substituted ammonium hydroxide with the sulfonic acid or with an acyl halide thereof. For example, by reaction of a sulfonic acid such as p-toluenesulfonic acid with a tetraalkylammonium hydroxide such as tetraethylammonium hydroxide there is obtained tetraethylammonium p-toluenesulfonate, use of which in the presently provided process has been found to give very good results. Other presently useful quaternary ammonium sulfonates are, e.g., tetraethylammonium oor m-toluenesulfonate or benzenesulfonate; tetraethylammonium o-, mor p-cumenesulfonate or o-, mor p-ethylbenzenesulfonate, tetramethylammonium benzenesulfonate, or o-, mor ptoluenesulfonate; N,N-di-methylpiperidinium o-, mor ptoluenesulfonate or o-, mor p-biphenylsulfonate; tetrabutylammonium alphaor beta-naphthalenesulfonate or o-, mor p-toluenesulfonate; tetrapropylammonium mor p-amylbenzenesulfonate or alpha-ethyl-beta-naphthalenesulfonate; tetraethanolamrnonium o-, mor p-curnene sulfonate or o-, mor p-toluenesulfonate; tetra-butanolammonium benzenesulfonate or p-Xylene-3 -sulfonate; tetrapentylammonium o-,- mor p-toluenesulfonateor o-, mor p-hexylbenzenesulfonate, tetrapentanolammonium p-cymene-3-sulr'onate 'orj benzenesulfonate; methyltriethylammonium o-, mor p-toluenesulfonate or mesityle'ne-Z-sulfonate; trimethylethylammonium o-Xylene-4-sulfonate or o-, mor p-toluenesulfonate; triethylpentylammonium alphaor beta-naphthalene sulfonate or o-, mor p-butylbenzenesulfonate, trimethylethanolammonium benzenesulfonate or o-, mor p-toluenesultonate; N,N- di-ethylpiperidinium or N-methyl-pyrrolidiniurn o-, mor p-hexylbenzenesulfonate or o-, mor p-toluenesulfonate, N,N-di-isopropyl or N,N-di-butylmorpholinium o-, mor p-toluenesulfonate or o-, -mor p-biphenylsulfonate, etc.

carboxamides can be reduced to .diamines or. hydrolyzed to dicarboxylic acids for use in preparing polyamides in similar manner.- I a Y What is claimed is: v a

1. The method ofproducing reduced,. coupled compounds which comprises subjecting a solution of .olefinic compound selected from the group consisting of cycloalkl-enecarboxylates, -carboxamides and cyanides in which the cycloalkene has 4 to 8 carbon atoms in the ring, to electrolysis, in a cell in which both anode and cathode are in actual'physical contact with electrolysis medium, the solution being in contact with a cathode having a hydrogen overvoltage greater than that of copper and containing water, at least about 10% by weight of olefinic The tetraalkylammonium salts of the aryl or alkarylsuh fonic acids are generally preferred for use as the salt constituents of the electrolysis solution because the electrolyses in the tetraalkylammonium sulfonatcs are exclusively electrochemical processes.

Among the ammonium and amine sulfonates useful as electrolytes in the present invention are thealkyl, aralkyl,

and heterocyclicamine and ammonium sulfonates, in'

and included by the terms amine and ammonium. The sulfonate radical can be from aryl, alkyl, alkaryl or aralkyl sulfonic acids of various molecular weights up to for example 20 carbon atoms, preferably about 6 to 20 carbon atoms, and can include one, two or more sulfonate groups. Any of the quaternary ammonium sulfonates disclosed and claimed in my copending application S.N. 75,123 filed I DecemberlZ, 1960, can suitably be employed. 7

Another especially suitable class of salts for use in the present invention are the alkylsulfate salts such as methosulfate salts, particularly the amine and quaternary ammonium methosulfate salts. Methosulfate salts such as a the methyltriethylammonium, tri-n-propylmethylammonium, triamylmethylammonium, tri-n-butylmethylammonium, etc., are very hydroscopic, and the tri-n-butylmethylammonium in particular forms very concentrated aqueous solutions which dissolve large amounts of organic materials. In general the amine and ammonium cations suitable for use in the alkylsulfate salts are the same as those for the sulfonates. V V V Various other cations are suitable for use in the present invention, e.g., tetraalkylphosphonium and trialkyl sulf onium cations,'particularly as sulfonate salts formed from sulfonic acids as described above, or as methosulfate salts.

The 2,2-biscycloalkane carboxylates are high boiling materials which can be used as lubricants or heat transfer media. These esters, as Well as the 2,2'-biscycloalkanecarbonitriles can be hydrolyzed by aqueous acid or alkali to the dicarboxylic acids which can be condensed with diamines,-e.g.,' hexamethylenediamine, to prepare polye compound and at least 5% by Weight of salt to make the solution conductive and separating the reduced, coupled product from the solution.

2. The method of claim 1' in which a cycloalk-l-ene cyanide is hydrodimerized to a 2,2-bi s(cycloalkane cyanide).

V 3. The method of claim 1 in which the solution comprises a salt'selected from the group consisting of amine and ammonium sulfonates and alkyl sulfates.

4. The method of hydrodimerization which comprises subjecting an aqueous solution of olefinic compound selected from the. group consisting of cycloalk-l-ene carboxylates, -carboxamides and cyanides in which the cycloalkene group has 4 to 8 carbon atoms in the ring to electrolysis in acell in which both anode and cathode are in actual physical contact with electrolysis medium, the solution being in contact with a cathode having a hydrogen overvoltage greater than that of'copper, causing development of the cathode potential requiredfor'hydrodimerization, the solution containing at least about 10% by weight ofolefinic compound and at least 5% by weight salt which discharges atnumerically lower cathode potentials than the olefinic compound and having a pH above about 6, and recovering the'hydrodimerized product.

'5. The method of claim 4 in which the olefinic compound is an alkyl cyclohexenecarboxylate.

I 6. The method of claim 4 'in which the olefinic pound is a cyclohexenecyanide.

'7. The method of claim 4 in which thexolefinici compound is a cyclopentene cyanide. V

8. The method of claim 4 in which the pH 'is about 7 to about 9.5.

9. The method of claim 4 in which l-cyanocyclohex- .l-ene is hydrodimerized'to 2,2'-bis(cyclohexanecyanide) COIII- {employing a mercury cathode at a cathode potential of 10. The method of claim 1 in which the pH is in the e range of about 3 to about 12.

amides suitable for coating'and molding or fiber-forming applications. The 2,2'-biscycloalkanecarbonitriles can also be hydrogenated or otherwise reduced to diamines References Cited by the Examiner UNITED STATES PATENTS 2,632,729 3/53 Woodman 204--72 I 2,726,204 12 /55 Park et a1 204-72 MURRAY TI LLMAN, WINSTON A. DOUGLAS,

Examiners.

Claims (1)

1. THE METHOD OF PRODUCING REDUCED, COUPLED COMPOUNDS WHICH COMPRISES SUBJECTING A SOLUTION OF OLEFINIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF CYCLOALK1-ENECARBOXYLATES, -CARBOXAMIDES AND CYANIDES IN WHICH THE CYCLOALKENE HAS 4 TO 8 CARBON ATOMS IN THE RING, TO ELECTROLYSIS, IN A CELL IN WHICH BOTH ANODE AND CATHODE ARE IN ACTUAL KPHYSICAL CONTACT WITH ELECTROLYSIS MEDIUM, THE SOLUTION BEING IN CONTACT WITH A CATHODE HAVING A HYDROGEN OVERVOLTAGE GREATER THAN THAT OF COPPER AND CONTAINING WATER, AT LEAST ABOUT 10% BY WEIGHT OF OLEFINIC COMPOUND AND AT LEAST 5% BY WEIGHT OF SALT TO MAKE THE SOLUTION CONDUCTIVE AND SEPARATING THE REDUCED, COUPLED PRODUCT FROM THE SOLUTION.