2,697,119 United States Patent Office Patented Dec. 14, 1954 2 liquid phase into the body of the reaction mixture or 2,697,119 bypassing it in vapor phase into the reaction mixture PROCESS FOR CHLORNATION OF DIETHYL either, alone or mixed with an inert gas such as nitrogen ETHER or carbon dioxide. Everett E. Gilbert, Flushing, Julian A. Otto, Long Island The chlorinated oxy ethane compounds employed as City, and Benjamin Veldhuis, Bayside, N.Y., assignors Solvents for the process may contain from 2 to 6 carbon to Allied Chemical & Dye Corporation, New York, atoms. Suitable solvents of this type include chlorine N.Y., a corporation of New York Substitution products of ethyl alcohol, diethyl ether, acet aldehyde, acetaldehyde acetal, acetaldehyde alcoholate No Drawing. Application April 6, 1949, 0 Serial No. 85,934 (CH3CH-O CH) 5 Claims. (C. 260-601) (bH This invention relates to the chlorination of ether and is particularly concerned with the conversion of ether acetic acid and ethyl acetate. Examples of specific com to dichloracetaldehyde alcoholate and chloral. 5 pounds suitable as solvents, in accordance with the above, In the past, chloral has been manufactured commer ae cially by chlorination of alcohol. This reaction, how CH2ClCH2OH, CHCl2CH2OH, CH3CHCIOC2H5 ever, is slow, hazardous, and of a highly complex nature, CH2CICHCIOC2H5, CHCl2CHCIOC2H5 requiring careful control and handling to obtain satis factory yields of chloral. While it has been proposed 20 CCl3CHCIOC2H5, CH2CCHO, CHCl2CHO to prepare chloral from diethyl ether by chlorination, yields of the desired product have generally been so small CCl3CHO, CH2CICH(OC2H5)2, CHCl2CH(OC3H5)2 and the chlorination procedure has been so hazardous CCl3CH(OC2H5)2 that the process has never been commercialized. As is CH2ClCHO CH Well known, chloral is the organic raw material employed 25 in preparing the important insecticide DDT (pp' dichlo ÖH rodiphenyl-1,1,1-trichloroethane). DDT is produced by CHCl2CHO CH reacting chloral with chlorobenzene in the presence of ÖH Sulfuric acid. In addition to its use as an intermediate C Cls CEO CH in the production of chloral, dichloracetaldehyde alco 30 holate is used for making the insecticide di(p-chloro bH phenyl) dichloroethane. CH2CICOOH, CHCl2COOH, CCl3COOH It is an object of the present invention to provide an improved process for the chlorination of ether. An CH2CCOOC2H5, CHCl2COOC2H5, and CCl3COOC2H5 other object is to produce dichioracetaldehyde alcoholate 35 The preferred solvents are chloral and dichloracetalde and chloral in high yields by the chlorination of diethyl hyde alcoholate, the principal products of our process, ether. A further object of the invention is to provide the dichloracetaldehyde alcoholate usually being em simple liquid phase processes minimizing explosion haz ployed in the form of mixtures with monochloracetalde ards and adapted for either batch or continuous oper hyde alcoholate, such mixtures predominating in the di ation. Yet another object of the invention is to provide 40 chlor compound. Acetic acid may be used as solvent procedure involving continuous operation for produc for the process, but when this solvent is used, it be tion of chloral under optimum yield conditions by chlo comes chlorinated so that the actual solvent present rination of diethyl ether. The invention further aims during the reaction is a mixture of chlorinated acetic to produce conversion of dichloracetaldehyde alcoholate acids. The solvent may be recovered from the reaction to chloral in good yield. Further objects of the invention 45 mixture and used for succeeding charges of reactants. will be apparent from the following detailed description Thus, when acetic acid or mono- or dichloracetic acid is thereof. employed initially, the final solvent after several cycles In accordance with the invention, the chlorination of may be primarily trichloracetic acid together with chloral ether may be carried out with facility and with produc resulting from the reaction taking place in the reaction tion of high yields of the desired chlorinated products mass. If dichloracetaldehyde is employed initially as by reacting the ether with chlorine and an equimolar Solvent in making chloral, the final solvent may be sub quantity of water in a reaction mixture at 50-130° C. stantially its chlorinated derivative, namely, chloral. saturated with chlorine and containing as solvent a chio Further, if the above noted chlorinated acetaldehyde alco rinated oxyethane compound having not more than 6 holates should be employed as solvent, the final solvent carbon atoms and 0 to 5 mols of water per mol of such may be chloral, since such alcoholates, as pointed out chlorinated oxyethane compounds in addition to the hereinafter, are intermediate partial chlorination products aforementioned equimolar quantity of water to ether in the chlorination of ether to chloral in accordance with required for reaction. The chlorine concentration may the invention. The amount of solvent employed is not be maintained by gradual or intermittent addition of critical. Generally, the chlorine, ether and water are chlorine along with or alternately with additions of ether. 60 introduced into a relatively large body of the solvent. The one mol of water required for reaction with each Throughout the reaction period, the chlorine avail mol of ether may be added initially to the solvent prior able for reaction is generally maintained in excess of to introduction of ether and chlorine. However, such the theoretical amount required to react with the ether water necessary for reaction with the ether, as well as starting material present for obtaining the desired prod certain additional preferred quantities of water as here 65 uct. For example, in production of chloral according inafter specified, is more desirably introduced into the to the equation, reaction mixture also by gradual or intermittent addi tion along with or alternately with the chlorine and ether, the reaction mixture being anhydrous or containing up 8 mois of chlorine per mol of diethyl ether are theoreti to 5 mols of water per mol of chlorinated oxy ethane 70 cally required as the minimum proportion of chlorine compounds employed as solvent. By carrying out the necessary to form chloral. In practice of the invention process in the manner prescribed above, chlorination of an excess of chlorine is preferably employed, the amount the ether takes place rapidly with a minimum of side of chlorine utilized ranging from 8 upwards to as high reactions, resulting in high yields of the desired product. as and beyond 15 mols per mol of ether, depending upon The chief products produced in accordance with the 75 the efficiency of operation. Aside from economic con process are chloral and dichloracetaldehyde alcoholate. siderations, there is no critical upper limit of excess Both anhydrous ether and commercial or technical chlorine which may be employed. In good commercial ether containing water may be employed with allowance operation, the amount of chlorine utilized ranges about made in the latter case for water content in relation to 8 to 10 mols per mol of ether. In the preparation of the water employed in chlorination. The ether may be 80 dichloracetaldehyde alcoholate from diethyl ether in ac added gradually to the reaction mixture by passing it in gordance with the invention, at least 3 mols of chlorine 2,697,119 3. 4 are required per mol of ether as shown by the probable a portion of such catalytically acting water is furnished course of the reaction noted below: by water initially introduced into the reaction mixture prior to addition of chlorine and ether, while a portion is provided by introduction of water into the reaction 5 mixture together with the chlorine and the ether starting material. in the preferred mode of procedure for chlorinating ether in accordance with the invention, water in quantity up to 5 mols per mol of chlorinated oxy ethane com In general, however, from 3 to 7 mols of chlorine per 0. pounds employed as solvent is added to the anhydrous mol of ether are utilized in the above reaction for making solvent material prior to introduction of ether and chlo dichloracetaldehyde alcoholate. Usually, in accordance rine. The amount of water thus initially added to the with our process, the solvent is first saturated with chio solvent may vary considerably. However, when solvents rine prior to introduction of the ether. As applied par which form monohydrates, e.g. dichloracetaldehyde or ticularly to batch operation in production of chioral, chloral, are employed, sufficient water to form the cor after the solvent is thus saturated, a portion of the responding hydrate, i. e. about one mol per no of sol chlorine is gradually added along with the ether and vent, is usually first added. In calculating the amount water while the remainder of the chlorine is added after of water present in the reaction mixture, such water is all the ether has been introduced, to complete chio intended to include any water of hydration present in rination to chloral. As already noted and indicated in the above equations, 20 the solvents employed. one mol of water is required for reaction with each The water being introduced into the reaction mixture mol of ether starting material in production of both during introduction of the ether may be added to the dichloracetaldehyde alcoholate and chloral. While one ether or it may be added in vapor form to the chlorine mol of water per mol of ether is theoretically all that prior to introduction of the ether or chlorine into the is necessary for carrying out the reaction, in a more satis 25 solvent. Preferably, however, the water is added sep factory embodiment of the invention process, water in arately to the reaction mixture during addition of the addition to that which reacts chemically with the ether other reactants. is included in the reaction mixture.