Patented Apr. 2, 1947 2,419,488

UNITED STATES2,419,488 PATENT OFFICE PRODUCTION of MONoCHLoRo DERIVA TIVES OF UNSATURATED NITRILES Harris A. Dutcher, Borger, Tex, assignor to - Phillips Petroleum Company, a corporation of , Delaware. - No Drawing. Application June 5, 1944, Serial No. 538,880 11 Claims. (CI. 260-464) 1 2 The present invention relates to the production Heretofore, 3-chloroacrylonitrile has been pro of chlorine derivatives of unsaturated nitriles by duced as a by-product of the direct substitutive the reaction of acetylene or acetylenic hydrocar- chlorination of acrylonitrile in the vapor phase bons with cyanogen chloride. More particularly over active carbon at a temperature between ap the invention relates to the production of 3- 5 proximately 200° and approximately 550° C. chloroacrylonitrile (Long, U. S. Patent No. 2,231,363). The process (2-chlorovinyl cyanide, C1-CH=CH-CN) yields 2-chloroacrylonitrile as the principal prod and Simil uct. No other methods for the production of 3 Sigrissy int chloroacrylonitrile. Or other monochloro deriva acetylenic hydrocarbons and cyanogen chloride. ? tly Of "EastE ae s ich The principal object of the present invention have found that acetylene and acetylenichy is to provide a process for the production of drocarbons may be reacted with cyanogen halides monochloro derivatives of unsaturated nitriles, to produce monohalogen-substituted unsaturated Such as 3-chloroacrylonitrile, by the reaction of . nitriles, The reaction ls facilitated by certain acetylene and cyanogen chloride. 15 Ef which are referred to more specifically Another object of the present invention is to eeinate. . . . provide a cES F.E.E.E., Cyanogen chloride is a readily condensible gas carbons.action of cyanogen chloride and acetylenic hydro- andhaYingeting a boiling point point within 9 approximately the range of approxi659. Other objects and advantages of the invention, 20 alcoholmately 12.5and to ether. 15.5°C. Cyanogen It is very chloride soluble inmay water, be Some of which are referred to more specifically readily prepared by the action of chlorine on hy-. - hereinafter, will be apparent to those skilled in drogen cyanide. Investigations of methods for theMonochloroderivatives art to which the invention of unsaturated pertains. nitriles, the prepartif yogeneride Wee de Such as 3-chloroacrylonitrile scribed by T. Slater Price and Stanley J. Green (2-chlorovinylcyanide, -cyano-2- ...... chem.(J. Soc. Abs., Chem. 1920, Ind., vol.14 1920, page vol.39, 2056). pages It 98-101T;has been chloroethylene, Cl-CH-CH-CN), reported that at 37 c. cyanogen chloride does 3-phenyl-3-chloroacrylonitrile . . . . . not react with ethylene (Ronald B. Mooney and (2-phenyl-2-chloro-vinyl cyanide, '... 30 Hugh G. Reid, J. Chem. Soc. (London), 1931, --rrrty-ri. page 2597)...... and 2-chloro-1,3-butadienyl' cyanide' . '. . '... occurReactions with othersimilar cyanogen to those halides,of cyanogen such chloride as cy (3-chloro-2,4-pentadienenitrile, s. . : ranogen bromide and cyanogen iodide, but the CH=CH-cci)=CH-CN)---- 35 interestproducts as are the not chloro at present derivatives of as greatof unsaturated industrial and similar compounds, are products of poten- nitriles. i...... tial industrial interest. They possess many of the In accordance with a specific embodiment of properties which make acrylonitrile desirable as . . the process of my invention, cyanogen chloride is . dienematerial to form for syntheticcopolymerization rubber. withCopolymers 1,3-buta of acetylenevolatilized inand an inerpassed solven thogh such a assolution hexane orof butadiene and Such monochloroderivatives of un- othesaturated hydrocarbons. The resulting 3 Saturated nitriles, with or without acrylonitrile chloroacrylonitrile may be separated from the un advantagesG G unsaturated over simple E. copolymers Eis someof butadiene E. 45 reactederably in acetylene the presence and solvent of a substance by distillation, capable pref- of . . . . . dieneand acrylonitrile and dichloro and derivatives over copolymers of acrylonitrile of buta- and cartriro,Elian nantioxidant antioxidant or inhibitor of ppoly. ly . . Vercopolymers of ptdiene and styrene con Instead of using the foregoing procedure, some tailing chlorop9pionitriles as comonomers. . . what better yields are obtained when catalysts These monochloro derivatives of unsaturated o, which promote the addition reaction are used. nitriles may be hydrolyzed in conventional man s such as a catalyst and may ner to produce the corresponding monochloro. ------...-- Into an aqueous solution of . saturated acids, for example, 2-chloroacrylic cuprous chloride, for example, one consisting of and they may be hydrogenated to yieldi 'grams of cuprous chloride, 250 grams of am- . chloro saturated nitriles, such as 3-chlo monium chloride, 30-grams of copper metal pow-. . . pionitrile, in the presence of catalysts such asc er, 15 cc. of concentrated hydrochloric acid and per (Reppe and Hoffmann, U. S. Patent. No 200 cc. of water, are passed streams of acetylene's ent1,891,055) No. 2,334,140). and Raney The nickel resulting (Winans, hydrogenated U.S. Pat and. . . .cyanogen . . . . Y.T. chloride- - at- - - such- flow- - - - rates- - that- - - - an- " . product, for example, 3-chloropropionitrile, can approximately equimolecular ratio of reactants is . be dehydrochlorinated to yield acrylonitrile 60 maintained. The catalyst solution is maintained. (Pieroh, U. S. Patent No. 2,174756). ... preferably at a temperature of approximately 200 2,419,488 3 4. to 210 F. The chloroacrylonitrile that is formed able for extensive investigation and since the re may collect as an oily layer or may be volatilized action products are rather complex and have not with the unreacted acetylene and cyanogen chlo heretofore been identified in other reactions, so ride, depending on the reaction temperature. If that their separation and identification cannot be volatilized, it can be separated from the effuent readily accomplished. In the reaction of meth vapors by fractional condensation. The con ylacetylene and cyanogen chloride, for example, densed crude chloroacrylonitrile may then be sub it has not been established conclusively whether sequently purified by fractional distillation, using the resulting product is a polymerization inhibitor in this operation. Al ternatively, the total effluent may be condensed 0 and the chloroacrylonitrile recovered therefrom on-on-onl and from other products formed in the reaction 3-chloro-3-methylacrylonitrile by fractional distillation. O In accordance with another method for the CH-C=CH-Cl practice of my invention, which is preferred for 5 N certain purposes, cyanogen chloride and acetyl ene, with or without a diluent gas such as nitro 3-chloro-2-methylacrylonitrile gen, are passed in approximately equimolecular because of the difficulty of separation and iden proportions over a solid contact catalyst which tification of the products, promotes the reaction at a temperature within 20 Although the foregoing description is directed the range of approximately 100° to 400° C. Solid particularly to the reaction of cyanogen chloride culprous chloride or cuprous cyanide is a suitable With acetylene, in both vapor and liquid phase, catalyst, although barium cyanide, sodium cya to produce 3-chloroacrylonitrile, it will be obvious nide, potassium cyanide, and similar alkali and that by suitable conventional modification the alkaline-earth metal cyanides may be used. processes can be readily adapted to the produc Such solid contact catalytic materials, when used tion of other monochloro derivatives of unsat in the process of my invention, are preferably urated nitriles by the reaction of cyanogen chlo deposited or coated on such adsorbent supporting ride and acetyllenic hydrocarbons. Suitable acet or carrier materials as charcoal, bauxite, fuller's yenic hydrocarbons for use in Such processes are earth and the like. Conventional methods may 3. methylacetylene (propyne, allylene), ethylacet be used for preparing such supported catalytic ylene (1-butyne), dimethylacetylene (2-butyne, materials. For example, a barium cyanide cata Crotonylene), vinylacetylene (3-buten-1-yne) as lyst Suitable for use in the process is prepared well as aromatic acetylenic hydrocarbons such by impregnating activated charcoal with an aque as phenylacetylene and the like. In connection ous solution of barium cyanide and thereafter 35 with acetylenes containing a double bond in the heating the resulting material to remove water; molecule, such as vinylacetylene, it is desirable Such alternate impregnation and drying may be to maintain the reaction conditions within more repeated as often as necessary to obtain a cata critical limits in order to obviate any possible lytic material with the desired content of barium reaction of the double bond. However, a rather cyanide. 40 wide latitude is permitted between reaction con Wide variation is permissible in the proportions ditions which favor the reaction of a triple bond of the reactants which are used in the process, as in acetylene and those which promote sub These will largely be preselected with a view stantial reaction of a double bond. toward minimizing or obviating the polymeriza Examples of preferred methods of practicing tion of one or another of the particular reactants. 45 the invention are set forth hereinafter, but it Generally equimolecular proportions of the re is to be understood that these examples are actants are used although, when an excess of merely illustrative and are not to be construed One reactant is used, it preferably is the acet as limitations of the Scope of the invention. ylenic hydrocarbon, which is generally less read Eacample 1 ily polymerized than the cyanogen chloride. In 50 Into a concentrated solution of acetylene in vapor-phase reactions, the use of an inert di commercial solvent hexane is passed a slow uent gas such as nitrogen is generally desirable stream of cyanogen chloride gas while the reac since the temperatures which are used in such tion mixture is maintained at a temperature of reactions are substantially higher than those approximately 20° C. After substantial amounts used in the liquid-phase processes of the inven 55 tion. of cyanogen chloride pass through the mixture The reaction which is involved in the produc without being absorbed, the resulting products tion of monochloro derivatives of unsaturated are recovered, nitriles is believed to be that expressed by the To recover the 3-chloroacrylonitrile which is following equation: formed in the reaction, the product is distilled 60 in the presence of hydroquinone as a polymeriza X-CeC-Y -- C1-CN - X---Y tion inhibitor, through a fractional distillation C1 CN column. The unconverted acetylene and cy anogen chloride are expelled first and thereafter in which X and Y are hydrogen or alkyl radicals the solvent hexane and 3-chloroacrylonitrile are and Y is the shorter or has the lower molecular 65 recovered. A substantial yield of the latter is weight of the two, if they are not identical. The obtained. cyanide radical of the cyanogen chloride is be Eacample 2 lieved to add to that carbon atom that is con nected to the triple bond to which the shortest Cuprous chloride solution is prepared by or the lightest molecular weight substituent is 70 adding 500 grams of cuprous chloride, 250 grams attached and the chlorine is believed to add to of ammonium chloride, 30 grams of copper metal the carbon atom adjacent that to which the cya powder, and 15 cc. of concentrated hydrochlo nide radical adds. However, I am not at all ric acid to 1200 cc. of water. The solution is certain that such is invariably the rule, since placed into a flask provided with a stirrer and alkyl-substituted acetylenes are not readily avail 75 two gas inlet tubes discharging beneath the sur 2,419,488 5 6 face of the solution and an outlet tube. The 3-chloroacrylonitrile which compriseS reacting a flask is heated to approximately 95° C. and main mixture of phenylacetylene and cyanogen chlo tained at that temperature while slow streams of ride at a temperature in the range from 20° to methylacetylene and cyanogen chloride preheat 400° C. ed to approximately 50° C. are passed into the 5 6. A process for the production of a mono flask at about equal gas flow rates. After a sub chloro derivative of an unsaturated nitrile which stantial portion of an oily material has been comprises reacting a mixture of acetylenic hy formed, the passage of the gases to the mixture drocarbon and cyanogen chloride in the presence and the stirring are stopped. The oily layer is of a cuprous salt at a temperature in the range separated and the chloro derivatives of methyl 10 from 20° to 400° C. acrylonitrile are recovered by fractional distilla 7. A process for the production of a mono tion. chloro derivative of an unsaturated nitrile which Eacample 3 comprises reacting a mixture of acetylenic hy drocarbon and cyanogen chloride in the presence Acetylene and cyanogen chloride preheated to 5 of a solid contact catalyst comprising a Sub approximately 200 C. are charged at approxi stance Selected from the group consisting of cu mately equal volumetric rates to a mixing ZOne prous chloride, cuprous cyanide, and alkali and where the combined stream is further mixed alkaline earth cyanides at a temperature in the with nitrogen gas preheated to approximately range from 100° to 400° C. 200 C. in the proportion of 2 volumes of nitro 20 8. A process for the production of a mono gen to each volume of mixed reactant Stream. chloro derivative of an unsaturated nitrile which The combined streams are then passed over a comprises passing in vapor phase a mixture of catalyst consisting of barium cyanide deposited an acetylenic hydrocarbon and cyanogen chlo On adsorbent charcoal that is disposed in a cat ride at a temperature within the range of ap alyst tube. The effluent is fractionally con proximately 100 to approximately 400 C. into densed, so that the 3-chloroacrylonitrile pro contact with a Solid contact catalyst comprising duced is separated from the lower-boiling acet a Substance selected from the group consisting ylene, cyanogen chloride and nitrogen. of cuprous chloride, cuprous cyanide and alkali The crude condensed 3-chloroacrylonitrile is and alkaline-earth metal cyanides. subsequently subjected to fractional distillation 9. A process for the production of 3-chloro in the presence of a polymerization inhibitor, acrylonitrile which comprises passing in vapor whereby a good yield of the desired product is phase a mixture of acetylene and cyanogen chlo obtained. ride at a temperature within the range of ap Eacample 4 proximately 100 to approximately 400° C. into Phenylacetylene is substituted for acetylene in 35 contact with a solid contact catalyst comprising Example 3 and the process is conducted substan a Substance Selected from the group consisting tially as described in Example 3. The product of cuprous chloride, cuprous cyanide and alkali obtained contains a substantial proportion of 3 and alkaline-earth metal cyanides. phenyl-3-chloroacrylonitrile. 10. A process for the production of 3-chloro 40 acrylonitrile which comprises passing in vapor Eacample 5 phase a mixture of acetylene and cyanogen chlo By substituting a catalyst consisting of cuprous ride at a temperature within the range of ap cyanide deposited on bauxite for the catalyst of proximately 100° to approximately 400° C. into Example 3 and otherwise conducting the process contact with a solid contact catalyst consisting as therein described, a good yield of 3-chloro 45 of cuprous cyanide deposited On bauxite. acrylonitrile is obtained. 11. A process for the production of 3-chloro Although the foregoing description comprises acrylonitrile which comprises passing in vapor preferred embodiments of my invention, it is to phase a mixture of equal volumes of acetylene be understood that variations and modifications and cyanogen chloride diluted with nitrogen in 50 the proportion of 2 volumes to each volume of may be made therein without departing sub acetylene and cyanogen chloride at a tempera stantially from the scope of the invention or the ture of 200° C. over a catalyst consisting of cu appended claims and that the invention is not prous cyanide deposited on bauxite, and recov to be limited except as specified in the appended ering 3-chloroacrylonitrile so produced from the claims. claim: 55 resulting effluent. 1. A process for the production of a monohalo HARRISA DUTCHER, derivative of an unSaturated nitrile which com prises reacting a mixture of acetylenic hydrocar REFERENCES C TED bon and a cyanogen halide at a temperature in The following references are of record in the the range from 20° to 400° C. 60 file of this patent: 2. A process for the production of a mono UNITED STATES PAENS chloro derivative of an unsaturated nitrile which comprises reacting a mixture of acetylenic hy Number Name Date drocarbon and cyanogen chloride at a tempera 2,326,095 PTanni ------Aug. 3, 1943 ture in the range from 20° to 400° C. 65 2,325,984 Sarbach ------Aug. 3, 1943 3. A process for the production of 3-chloro 2,324,854 Kurtz et al. ------July 20, 1943 acrylonitrile which comprises reacting a mixture 2,322,696 Kurtz et al. ------June 22, 1943 of acetylene and cyanogen chloride at a temper FOREIGN PATENTS ature in the range from 20 to 400° C. 4. A process for the production of a mono 70 Number Country Date chloro derivative of methylacrylonitrile which 116,654 Australian ------Mar. 11, 1943 comprises reacting a mixture of methylacetylene and cyanogen chloride at a temperature in the OTHER, REFERENCES range from 20° to 400 C. Auwers et al., Liebig's Annalen, vol. 492, pp. 5. A process for the production of 3-phenyl s 283-292, 1932.