Patented Dec. 1, 1942. I 2,303,549 UNITED STATES" PATENT ‘OFFICE’ - 2,303,549 _- _ , rmrno'n roa MAKING mono-canon smranns ' . Amos G. Horney, East Cleveland, Ohio, assignor, by mesne assignments, to Air Reduction Com pany. Incorporated, a corporation of New York No Drawing. Application April 24,1939, Serial No. 269,793 , I‘

-6Claims. (CL260-658) ' ' i This invention relates to the sylithesis of hy - tuted' alk-ane is, as followsz-l-Normal ,propyl s1 j drocarbon compounds having the general for cohol is treated with HBr or NaBr and H2804 -- mula of CnHa and relates more particularly to to yield normal propyl bromide according, to the a‘ new and improved process for making cyclohy I following reaction: ' ‘H S04‘ - ' drocarbons. - ‘ > GI CHr-CHg-CHsOH-l-HB! -:-—v CHs-CHrCHgByI-HLO’ The present invention makes possible the pro duction or hydrocarbons of the general formula, This reaction product may be washed with water Just stated, i.~ e., ole?ns and cyclic compounds, and dilute alkali, dried and then puri?ed by dis- ' irom'ncn-cyclic, substituted hydrocarbons by a tillation to separate out the normal propyl bro new and improved process. Brie?y stated, this 10 mide. Treatment of this compound with chlo- _ - process includes the steps of providing a suitable rine gas at a pressure of about one or more at substituted alkane containing three or more car mospheres and at a temperature of between about bon atoms and two diilerent halogens selected~ 25" C. and 180° C. will yield a high percentage of‘ irom the group consisting of chlorine, bromine and ' 1-bromo-3-chloropropane and'limited amounts of a ' I iodine and then treating such a substituted alk'ane 15 1-bromc-2-chloropropane. Such substances may with zinc dust in suspension in a liquid medium, , be separated and puri?ed as above-described in which is preferably predominantly aqueous, in a the ?rst example and then treated separately ac manner to produce ole?ns or cyclohydrocarbons, cording to the second above mentioned step of ‘ of the general formula Cama the present invention to‘ produce respectively c'y The present invention will first be described 20 ‘clopropane and propenes , ' with speci?c reference to the production of cy Having provided a suitable substituted alkane, by the foregoing or equivalent methods, such a . clopropane. "- ‘ The production of a substituted alkane suit substituted alkane is thenvtreated according to ' able for the present purpose may be accomplished the second above mentioned step. When cyclo by any one or several different methods. 25 propane is the product desired, 1-bromo-3-ch1o- ' ' One such method is as ‘follows: Hydrogen bro ropropane is treated by being introduced slowly, mide is passed into _a ‘halogen substituted alkene, , as ‘by dripping it, into a liquid medium, which-is - such as allyl chloride, in the presence of a suit preferably predominatingly water and which con— able catalyst such as paraldehyde, or while ex ' tains zinc dust in suspension. This reaction mix posed to light, such as sunlight or ultra-violet so ture should be maintained at a temperature ‘of light. The resulting product will contain l-bro between about 70° C. and the boiling temperature mo-S-chloropropane and 2-bromo-1-chloropro of the reaction mixture which, in case substan pane, according to the following reaction: tially pure water is used, is 100° C. Since the reaction proceeds with greater rapidity at the 7 CH2C1—CH=CHa-l-HBr->CHaCl-CHa-CH:Br 35 higher temperatures, it is preferable to maintain the reaction mixture at between about 90° C. and and - ' about 98° C. ' CHaCl-CHBr-CH: V The rate of the reaction may be increased The product of the foregoing reaction may be somewhat byraising the boiling point of the liq washed with water and neutralized with an alkali, uid medium as may be done by adding salts such as sodium carbonate, dried and then dis thereto or increasing the pressure. ' tilled. Since the z-bromc-l-cholropropane boils The liquid medium may consist of water con at about 118° C.. it may be separated readily from ‘ taining as much as about 20% of ethyl alcohol. _ the'1-bromo-3-chloropropane which has‘a boil Other water-soluble, low-molecular-weight, or ing point of about 142° C. and each of these sub 45 ganic compounds such as alcohols, ketones and stances may thus be obtained with relatively high esters may be used with water, but none of these degrees of purity. The l-bromo - 3 - chloropro ‘ substances is necessary or desirable for they tend ~ pane, CHz-'-Cl—CHa-CHzBr, is a substituted al- . .to retard the rate of the reaction by lowering the kane which maybe treated according to the sec ond above mentioned step of this invention ior' boiling point. " . . 50 The gases generated by the reaction are passed conversion into cyclopropane. [The 2-bromo-1 thru a condenser which condenses any water va - chloropropane, CHsCl-CHBr-C?a, is a vsubsti por but permits the gaseous cyciopropane to pass tuted which may be treated bythe second therethru. This gas has .a boiling point of about above mentioned step of the present invention -32° C. After passing thru the condenser. this =ior conversion into propene. . _ . > Another method for making alsuitable to gas is collected and puri?ed, ii necessary, by any 2 I . aaoaea'e suitable means, for example, by liquefying. dis dehyde, propionaldehyde, paraformaldehyde, tilling and scrubbing with dilute potassium per benzaldehyde and nitrobenzaldehyde and a ketone manganate. - such as acetone. The residue remaining after the cyclopropane This reaction may be carried out under pressure has been generated contains zinc-chloridebro as high as about 100 lbs. per sq. inch and as low mide, ZnClBr, which may be recovered and used, as about atmospheric. Where the reaction is for example, in preparing normal propyl bromide carried out under the higher pressure and small from propyl alcohol by substituting this zinc amounts of the foregoing inhibitors are present chloridebromide for the HBr or NaBr in the re their inhibiting eifect in the presence of any of action hereinabove described for treating propyl the foregoing catalysts is substantially overcome alcohol. but when the reaction is carried out at about When propene is the product desired, the 1 atmospheric pressure the catalysts are not as bromo-2-chloropropane above mentioned is treat effective. , ed with a liquid medium containing zinc dust in I have found that when the allyl chloride hy the manner above described in connection with the drogen bromide reaction is carried out in the treatment of the 1-bromo-3-chloropropane and " presence of paraldehyde high yields‘ of l-bromo the propene gas is collected as generated. 3-chloropropane are obtained even when anti The foregoing description of the invention has oxidants such as hydroquinone, thio-cresol and been restricted to the preparation of cyclopropane acetic acid are present. . ‘ » and propene for reasons of clarity and de?nite 20 The temperature range within which hydrogen ness. It will be understood, however, by those bromide will react with allyl chloride to produce skilled in the art, that the present invention may good yields of 1-bromo-3-chloropropane is rather be practiced with any mixed halogen substituted wide.‘ For example, the reaction takes place at alkane containing from three to ten carbon atoms. as low a temperature as about —60° C. and pro For example, mixed halogen substituted alkanes 25 ceeds quite rapidly at temperatures between .containing as many as eight or ten carbon atoms +7‘ 0. and +35° C., and when the reaction tem - may be treated according to the present inven . perature is between the latter two temperatures tion to prepare cyclohydrocarbons or alkyl sub and the allyl chloridehas been freshly distilled stituted cyclohydrocarbons and oleiins containing and a suitable catalyst is present in small quan corresponding numbers of carbon atoms. 30 tities, yields of as vmuch as 85% of 1-bromo-3 It is important that the alkanes subjected to chloropropane have been obtained consistently. treatment by this invention should contain two This. application is a continuation-in-part of diiferent halogens selected from the group con . my co-pending application Serial No. 200,802 iiled ' sisting of chlorine, bromine and iodine. While April 7, 1938, now Patent No._2,219,260, issued iodine may be used, it is preferable, for economic 35 October 22. 1940. v . reasons, to use alkanes containing ‘chlorine and Having thus described the present invention so that those skilled in the art may be able to bromine. _- . Prior to this invention dimculty has been ex understand and practice the same, I state that perienced in controlling the amounts of i-bromo- 1 what I desire to secure by Letters Patent is de 3-chloropropane and z-bromo-i-chloropropane 40 lined in what is claimed. . . from the treatment of allyl chloride with hydro What is claimed is: ‘ ' gen bromide, i. e., the reaction was apparently . '1. The method ' of making bromo-chlor-al not well enough understood so that a high per kanes which includes the steps of treating a sub centage of one compound or the other could be stituted alkene containing three or more carbon forecast with assurance. _ 45 atoms and. chlorine with hydrogen bromide in the .1 have discovered that high yields of l-bromo presence of a catalyst selected from the‘ group 3-chloropropane can be made‘ with certainty and consisting of paraldehyde, propionaldehyde, para _ ‘assurance by treating allyl chloride with hydrogen formaldehyde, benzaldeh'yde, nitrobenzaldehyde. bromide in the absence of substances which in ' i 2. The method of making bromo-chlor-alkanes hibit‘ the reaction or, if such substances are 50 which includes the steps of reacting‘ allyl chlo- - present, by minimizing or overcoming their in ride with hydrogen bromide in the presence of a hibiting effect by the presence of small amounts of catalyst selected from the group consisting of . suitable catalysts or anti-inhibitors. Freshly dis paraldehyde, propionaldehyde, paraformalde tilled allyl chloride does not ordinarily contain any hyde, benzaldehyde,.nitrobenzaldehyde and sepa ' inhibitors and is “suitable’,’ for this reaction. 65 rating the" resulting 1-bromo-3-chloropropane Allyl chloride which has been stored for some time from other products of the reaction. in containers which do not include inhibitors, 3. The method of making bromo-chlor-alkanes such as'glass, earthenware or quartz containers, which includes the steps of reacting allyl chlo is also “suitable? for this reaction. . ‘ ride with hydrogen, bromide in the presence of a It is dlmcult to construct equipment, for carry simple aldehyde and separating the resulting 1 ing out the foregoing reaction‘ on a commercial bromo-3-chloropropane'from other products of scale, entirely from materials which are not in the reaction. a ' hibitors of the allyl chloride hydrogen bromide 4. The method of making bromoichlor-alkanes reaction. Materials such as glass, earthenware which includes the steps of reacting allyl chlo-‘ and quartz are not inhibitors but it is diiiicult to ride with hydrogen bromide in the presence of a construct commercial equipment composed en catalyst. selected from the group consisting of tirely of these materials. Equipment parts which paraldehyde, propionaldehyde, paraformaldee ' would normally be used, for example, parts com- I hyde, benzaldehyde, nitrobenzaldehyde and at a posed of inhibitors such as iron, Pioneer alloy, ' temperature between about —60° C. and about 1 glass ?ber with Bakelite binding, Hastelloy Band 70 +35’ 0. and separating the resulting i-bromo the like may be used to a limited, extent and pret 3-chloropropane from other products of the re

erably where they do not come into contact with . action. ' - . - I the liquid. Their inhibiting-effects can be over 5. The method of making bromo-chlor-alkanes come by the presence of a suitable catalyst. Suit which includes the steps of reacting allyl chloride able catalysts are simple aldehydes such as paral 15 with hydrogen bromide inthe presence of a cat- ' 2,803,540 ~ ', ' f I ' T - i' 3 chloride with hydrogen bromide at 's tempera-' slyst selected from the groupconsistinz of paral . ture between about '—60° C. and about +35° C., " delmde. , propionaldehyde, paratormaldehyde, at a pressure between about 100.1bs. per sq. inch _ benzaldehyde. nitrobenzaldehyde and under a and about atmospheric, and in the presence or a pressure ranging from about atmospheric pres catalyst selected from the group consisting of , sureto about ‘100 pounds per square inch and xparaldehyde, propionaldehydek per'aiormalde separating the resulting l-bromo-s-chloropro hyde,benzvaldehyde, nitrobenzaldehyde and recov pane from the other products‘ formed by such re ering the resulting 1-bromo-3-chloropropane. action.6. The method oi'makinz 1-bromo-3-ch1oroI I v AMOS G. HORNEY. propane which includes the steps of reacting ellyl i0.