Патент USA US2404706код для вставки
Patented July 23, 1946 2,404,706 UNITED STATES PATENT OFFICE 2,404,706 FLUORINATION Jesse Harmon, Wilmington, DeL, assignor to E. I. du Pont de Nemours & Company, Wilmington, '‘ Del., a corporation of Delaware No Drawing. Application October 4, 1943, > Serial No. 504,951 5 Claims. 1 (Cl. 260—653) 2 . This invention relates to the ?uorination of se being a halogen, with a ?uorinated methane in lected organic halogenated compounds, and more particularly to the ?uorination of unsaturated or ganic compounds by means of an organic ?uorin ating agent. Previous to the present invention, practically the only method for preparing ?uorine-contain ing organic compounds has been to replace chlo rine with ?uorine by means of various inorganic 5 the presence of from about 0.1% to about 20% by weight of the reacting materials of a Friedel Crafts type catalyst which is a chloride of a poly valent metal cation. A preferred embodiment of this invention comprises heating hexachloropropylene with chlorodi?uoromethane at a temperature within the range of from about 100° C. to about 200° C‘. reagents such as metallic ?uorides including silver 10 in the presence of an amount of anhydrous ?uoride, antimony ?uorides and mercuric ?uoride aluminum chloride, calculated on the basis of in the presence or absence of hydrogen ?uoride. ' the sum‘ of the weights of the hexachloropropy Such inorganic reagents are hazardous and ex lene and chlorodi?uoromethane, within the pensive, and their use is very restricted in appli range of from 0.1% to 20%. 7. cation. 15 By the expression “trihalomethyl ethylenic I have now discovered a process whereby tri compound” as used herein and in the appended‘ halomethyl ethylenic compounds may be ?uorin claims is meant an organic compound contain ated readily to provide ?uorine-containing‘ tri halomethyl ethylenic compounds. ing the grouping Accordingly, this invention has as an. object a 20 new method of producing ?uorine-containing or ganic compounds. A further object is ‘a safe, ?exible, practicable and economical method for ’ OX2 . =0 wherein the X substituents are halogen atoms and the double bond is a linkage in an aliphatic’ producing ?uorinated organic compounds. A still chain or in an alicyclic ring. further object is the employment as ?uorinating 25 The method for carrying out the reaction var-1 agents of readily and commercially available ?uo ies to ‘some extent with di?erent types of tri rine compounds. A still further object is the halomethyl ethylenic compounds, but the usual provision of a process which proceeds smoothly procedure consists in placing a given amount of and easily without undesirable side reactions. trihalomethyl ethylenic compound such as hexa Additional objects will become apparent from an 30 chloropropylene in a si1ver~lined autoclave with examination of the following description and chlorodi?uoromethane and a small amount of claims. ’ anhydrous aluminum chloride catalyst, and then These and other objects and advantages are ac heating the reaction mixture at about 100 to complished by the herein described invention 200° C‘. with agitation for several hours. which broadly comprises heating a trihalomethyl ethylenic compound, 1. e., a compound containing The following examples, in which proportions are given in parts by weight unless otherwise speci?ed, are given for illustrative purposes and a group having the general formula are not intended to place any restrictions or limi tations on the herein described invention: wasI 40 wherein the X substituents are halogens, and at least one of the X substituents is a halogen having an atomic weight of greater than 30, with a ?uorinated methane in the presence of a Friedel Crafts type catalyst. - . In a more restricted sense this invention com prises heating at a temperature within the range of from about 100° C. to about 200° C, a compound having the general formula X3C—CY=CY2 Example I A silver-lined high pressure reaction tube was charged with 15 parts of anhydrous aluminum chloride, 100 parts of hexachloropropylene and 45 150 parts of chlorodi?uoromethane. The re actor was agitated and heated at 150° C. for 10 hours, then at 200° C. for 2 hours. After cooling and releasing the pressure, the liquid solid reaction mixture was treated with Water wherein the X substituents are halogens, at least 50 and. the liquid was separated by decantation. one of the X substituents having an atomic weight The organic layer was washed with dilute aque of greater than 30, and the Y substituents are ous sodium hydroxide solution, then Water, and monovalent radicals selected from the group con was dried and fractionally distilled through a sisting of hydrogen, halogens and monovalent precision still when there were isolated: 68 parts alkyl radicals, at least one of the Y substituents 55 CHCls, B.P. Gil-62° 0., ND“? 1.4448; 41.3 parts 2,404,706 3 4 CFs—CCl=C'Cl2, B.P_ 86-88" 0., ND20 1.4103; and 4 parts CF2Cl-C‘Cl=CClz, BE’. 128° C. Example II The trihalomethyl ethylenic compounds hav ing one or more halogen atoms connected direct ly to the carbon atoms bearing the double bond are preferred since they are more stable and their trihalomethyl groups are more readily ?uori nated. Optimum results are had when the tri On repeating Example I at 100° C. there were isolated: halomethyl ethylenic compound subjected to Compound Pvaiéizgkllaty BoilingCrange, ND20 3 _______________________ __ CFz-CC1=OC]Z _____________ __ CFzC1—-CCI=CC1z_. . CFCh-OOI=CC12 ___________ __ OCl3—OOl=CCl2 ____________ __ 58 _ ?uorination in accordance with this invention has the general formula XaC—CY=CY2 wherein 10 the X substituents are halogens of which at least .one is a halogen having an atomic weight of greater than 30, the Y substituents are mono valent radicals selected from the group consist 1. 4390 ' 8 ___ 1. 4094 3. 5 25/15 mm ____ __ 1. 4596 4. 5 67 53-55/15 mm___ 35-36/2 mun..- 1. 5015 l. 5490 ing of hydrogen, halogens and monovalent hy drocarbon radicals, and at least one of the Y sub As hereinbefore stated, my novel process com stituents is a halogen, and particularly when the trihalomethyl ethylenic compound contains not more than 10 carbon atoms. The present process _is broadly applicable to fluorinated methanes and particular signi?cance prises fluorinating a trihalomethyl ethylenic compound wherein at least one of the three halogens in the trihalomethyl group has an atomic weight of greater than 30, with a ?uori nated methane in the presence of a Friedel is attached to the use of the commercially avail able ?uorinated methanes. Included among said ?uorinated methanes are dichloro?uoromethane, Crafts type catalyst. The resultant ?uorinated products contain a group having the general formula 25 . dichlorodi?uoromethane, chloro?uoromethane, chlorodi?uoromethane, bromodi?uorometha-ne, di?uoromethane, chlorotri?uoromethane; ?uoro trichloromethane, tri?uoromethane and tetra wherein n is a positive integer within the range ?uoromethane. I of from 1 to 3 and the X substituents are halo The catalysts employed in the present process gens having an atomic weight of greater than 30. It is to be understood that any trihalomethyl 30 are Friedel-Crafts type catalyst-s which are chlo rides 0r bromides of polyvalent metal cations,‘ and ethylenic compound in which at least one of the include such salts as aluminum chloride, alu three halogens in the trihalomethyl group has minum bromidebferric chloride, zinc chloride, an atomic weight of greater than 30 may be flu~ stannic chloride and the like. The proportion of orinated according to my novel process. How catalyst employed may vary within relatively ever, on account of the greater ease with which 35 the reaction proceeds therewith, the preferred wide limits'depending largely upon the nature'of the reactants and the products desired. Gener ally speaking, desirable results are obtained with pounds selected from the group of compounds the use of small amounts of catalyst correspond having the general formula X3C--CY=CY2, wherein the X substituents are halogens of which 40 ing to from about 0.1% to 20% by weight of the materials used. Advantageous results are some trihalomethyl ethylene compounds are com at least one is a halogen having an atomic weight of greater than 30 and the Y substituents are monovalent radicals selected from the group consisting of hydrogen, halogens and monovalent hydrocarbon radicals. Examples of monovalent hydrocarbon radicals represented by Y in the above formula are: methyl, ethyl, isobutyl, amyl, hexyl and cyclohexyl radicals. It is to be understood that the trihalomethyl ethylenic compounds ?uorinated by the processv of this invention contain the group times obtained by using a combination of catae lysts. The time required for carrying out the re; actions may vary from a few minutes to several days depending upon the nature of the reactants‘ and the other operating'conditions such as‘ terns peratu're, pressure and catalyst. In general it‘is‘ preferable to carry out the reaction in the absence of water. } " ‘ - The process may be operated continuously or intermittently. Additional ?uorinated methane may be added during the course of the reaction. The by-product halogenated methanes such ‘as wherein the X substituents are halogens, at least ' one of which is a halogen having an atomic chloroform in‘ the examples may be reconverted into ?uoromethanes by well known commercial processes and recycled. The reaction may be carried out in a closed system in‘ the liquid or vapor phase, or in the vapor phase by mixing group are: > the vapors of the trihalomethyl ethylenic com 60 pound and ?uorinate‘d methane and passing the mixture through a hot reaction tube containing the Friedel-Crafts type catalyst. The pressure I I I l at which the reaction is carried out is dictated euro-0:? and (HMO-0:? by the vapor pressure and otherpropertie's of In. addition to hexachloropropylene disclosed in 65 the reactants and products. Generally, however; Examples I and II, trihalomethyl ethylenic com it is carried out at superatmospheric pressures. pounds which may be ?uorinated by the proc The temperature at ‘which the reaction is e'f ess'of this invention include: ClF2C—-CC1=CF2, fected may vary over a fairly wide range, deh pending largely upon the nature of the reactants, the catalyst, the ‘results desired; and the other conditions of the reaction. However, it is .neces~ sary to carry out the reactions at an elevated weight of greater than 30. Examples of said Trihalomethyl ethylenic compounds in which the ethylenic double bond is present in a cyclo temperature. Optimum‘ yields are usually obL tained at temperatures within the range of from aliphatic ring’ as in cyclohexene may also be used. 75 about 1100 to 200° 0., but higher temperatures, ‘be’ 5 2,404,700 6 low that at which decomposition of the reactants and/or products occurs, are sometimes desirable. parting from the spirit and scope thereof, it is to be understood that I do not limit myself to the The reactions may be carried out in any suit able reaction vessel whose materials of construc tion are resistant to the action of the reactants and catalysts, and which are capable of with standing heat and pressure, such as stainless steel, silver and the like. The reaction is pref speci?c embodiments thereof except as de?ned in the appended claims. Having described the ‘present invention, the following is claimed as new and useful: 1. The process for preparing a compound hav ing the general formula FnX(3_n)C-CY=CY2 wherein n is a positive integer within the range of from 1 to 3, the X substituents are halogens having an atomic weight of greater than 30 and erably carried out with agitation, but agitation is not always necessary. The reaction and the separation or isolation of the products may be carried out simultaneously or in separate steps. The ?uorinated products prepared in accord ance with this invention are trihalomethyl ethyl enic compounds in which at least one of the three halogen atoms in the trihalomethyl group is a ?uorine atom. Said products have the gen eral formula FnX(3~n)C—-CY=CY2 in which for mula n is a positive integer within the range of ‘from 1 to 3, the X substituents are halogens hav ing an atomic weight of greater than 30 and the Y substituents are monovalent radicals selected from the group consisting of hydrogen, halogens and monovalent hydrocarbon radicals. It is to the Y substituents are monovalent radicals selected from the group consisting of hydrogen, halogens and monovalent hydrocarbon radicals, at least one of the Y substituents being a halogen, which comprises heating a compound having the general formula FmX(a-m)C—CY=CYz,. wherein m is a number smaller than 11. selected from the group consisting of zero and positive integers less than 3, the X substituents are halogens having an atomic weight of greater than 30 and the Y sub stituents are monovalent radicals selected from the group consisting'of hydrogen, halogens and be understood that a mixture of iluorinated - products in which n is l, 2 and 3 may be ob tained upon ?uorination of a given trihalomethyl ethyl'enic compound, e. g. a trichloromethyl ethylenic compound, but the compounds are us ually easily separated into de?nite fractions by : conventional methods such as fractional distilla tion. The relative proportions of the mono-, di and tri?uoromethyl ethylenic compounds ob monovalent hydrocarbon radicals, at least one of the Y substituents being a halogen, with a fluorinated methane in the presence of an an hydrous Friedel-Crafts type catalyst. 2. The process according to claim 1 wherein the heating is effected at a temperature within the range of from about 100‘? C. to about 200° C. 3. The process for preparing a compound hav ing the general formula FnX(3-n)C—-CY=CY2 wherein n is a positive integer within the range of tained will depend upon the reactants and condi from 1 to 3, the X substituents are halogens hav tions. " ing an atomic weight of greater than 30 and the By way of illustration, the ?uorination of hexa Y substituents are halogens, which comprises chloropropylene by chlorodi?uoromethane in the heating a compound having the general formula presence of aluminum chloride is represented be FmX(3—-m)C-—CY=CY2, wherein m is a number low: smaller than n'selected from the group consisting U of zero and positive integers less than 3, the X substituents are halogens having an atomic Weight of greater than 30 and the Y ‘substituents ing reagents. However, it is surprising that the are halogens, with a ?uoromethane in the presence of an anhydrous Friedel-Crafts type catalyst which is a chloride of a polyvalent metal cation. 4. The process for preparing a compound hav extremely stable ?uorinated methanes ‘such as ing the general formula FnX(3—n)C—CY=CY2 chlorodi?uoromethane can be used as a source of wherein n is a positive integer within the range of It is well known that the halogens in certain halogenated hydrocarbons can be replaced with ?uorine by means of various inorganic ?uorinat from 1 to 3, the X substituents are halogens hav ing an atomic weight of greater than 30 and the Y substituents are halogens, which comprises enic group. heating a compound having the general formula ‘The present invention is particularly advan tageous in that it affords a safe, ?exible, practic FmX(3_m)C—CY=CYz, wherein m is a number able and economical process of ?uorinating or- .' smaller than n selected from the group consisting ganic compounds of the character herein de of zero and positive integers less than 3, the X substituents are halogens having an atomic scribed. One of the advantages of said process weight of greater than 30 and the Y substituents is that ?uorinated methanes which may be used in this invention are commercially available; and are halogens, with chlorodi?uoromethane in the that said fluorinated methanes, such as chlorodi 60 presence of anhydrous aluminum chloride. 5. The process for preparing a compound hav ?uoromethane, which are extremely stable, can be used as a source of ?uorine for selectively ing the general formula FnC1(3—n)C-C‘C1=CC12 ?uorinating trihalomethyl ethylenic compounds wherein n is a positive integer within the range without affecting the ethylenic group. Another of from 1 to 3, which comprises heating hexa advantage is that the process may be operated chloropropylene with chlorodi?uoromethane in with a relatively small amount of expensive cat the presence of anhydrous aluminum chloride at alyst and that the reaction proceeds smoothly a temperature within the range of from‘about and easily without undesirable side reactions. 100° C. to 200° C. and thereafter recovering the fluorine for selectively ?uorinating trihalomethyl ethylenic compounds without affecting the ethyl As many apparently widely different embodi ments of this invention may be made without de 70 compound FnC1(3—n)C—CC1=CC12 by distillation. JESSE HARMON.