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 erablyreacted 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