44 1 IX.-Note on n Method of cfecting the substitution of Chlorine for I$ydroyeri irz. Organic C’orrzpounds BYHUGO MULLER. INthe investigation of Burmese naphtha madc a few years ago by Mr. Warren De La Rue and myself we eiideavourcd to obtain some definite iodine-compounds of thc hydrocarbons coritaincd in it by acting upon them with mono-and ter- cliloridc of iodine hoping that this reagent would act in this case in a similar \vily to that observed a short time hcfore by Brow 11 in tlie case of pyrome-conic acid. These experiments did not however givc tlie expected result but nierely the same chlorine-compounds that were already 0bt;iilictl by using chlorine only. Tlic result was the same when iodine was dissolved in tlie hydro-carbon mil chlorine passed into the deep violet-colonrcd solution.The oiily difference observable bctween the action of chloritic in prcsciicc of iodine and that of chlorine only was that in the forincr case thc action took place much more quickly tliari in the latter. Having some time ago commenced a scries of expcrimcnts with the vicw of obtaining from benzole the corresponding alcohol and acid I had occasion to invcstigatc the action of chlorine on this hydrocarbon. Chlorine is absorbed to some extent by bcnzole but if light be excluded no pcrceptiblc action takes place until the benzole is heated to the boiling point ;hydrochloric acid Is then liberated and chlorine-derivatives are formed but very slowly. In this reaction two series of compounds are formed namely CGH6C12 C6H,Cl, C61-16Clq and C,H,Cl C6W,C12 C6H3C13 The experience gained in the above-mentioned .experiments with Burmese naphtha induced me to try upon a large scale the action of chlorine upon benzole in the presence of iodine.When chlorine is passed into a saturated solution of iodine in benzole it is completely absorbed evcn when the current is mode-rately rapid and after the violet solution has become brownish red owing to the formation of monochloride of iodine hydrochloric MULLER ON THE SUBSTITUTlON OF CHLORIXE acid is liberatcd and chlorine-derivatives arc rapidly formed. In this may 1 hare 0-btained the compounds C6H,Cl C6H,C1, C6H ,C1, and wheu an excess of chlorine was used a beautiful crystalline compound which was previously obtained in small quan- tities 011 trcatiiig the hydrocarbons of Burmese naphtha in the same manner.It deserves to be noticed that whereas when chlorine acts alone upon bcnzole the chief products of the reactioii are formed by its dircct union mitli tlie hydrocarbon the action of chlorine in presence of iodine gives rise to substitution-products and the evolution of Iij+lrocliloric acid. I rcseri-e the dctailed description of tlie products of this re-action ‘and the method of obtaining tlicm in a pure state for a future conirriunication ;what I wish especially to draw attention to upon this occasion is the remarkable cffcct of iodine in facilitating the action of chlorine upon organic compounds. I have already ascertained tlint many substanccs which are actcd upon with great difficulty by cliloriiic donc and some of them only with the aid of direct sunliglit yield cliloriuc-products with great ease when acted upon in the maiiiwr dcscribed by chloririe in tlie presecce of iodine 1 have found for instancc that benzoic acid dissolved together with some iodinc in chloroform is acted upon by chlorine very readily with evolution of hyrlrochloric acid.Bisulpliide of carbon in which iodine is dissolved is acted upon by cliloriiic rciy frccly at its boiling point giving chloride of carbon cliloride of sulpliur and a highly volatile substance having a very irritating and puiigent cdour mliich is perhaps the chloro- sulpliicle of carlmxi which Kolbc believer1 he ltad obtained by exposing sulp!iicle of‘ carbon to the action of chlorine in dircct sunlight.The proccss I hare described promises to give this substance in sufficient quantity to admit of ascertaining its true nature. Wlicn cliloriiie is passcd into a solution of iodine in glacial acetic acid in thc cold tcrcliloridc of iodine is fornicd but the acid is not acted upon. If liowcvcr the acid is kcpt boiling whilst the clilorixie is being passed into it liydrocliloric 2cid is given off and cliloracctic acid is fornicd even in tlic dark. This affords a ready means of obtaiiiing .cliloracetic acid a substance whose preparation according to the usual method requires the aid of strong sunlight and is commonly very tedions. If the action of chlorine be continued a higher chlorinated acid is obtainkd which FOR HYDROGEN IN ORGANIC COMPOUNDS.43 does not solidify cven at O3 C. and which appears to he bi-chlor- acetic acid.* It seems likely that in this reaction the iodine acts merely as a carrier arid condcnser of the chlorine; the effect is very similar to that of some perclllorides like pentachloride of antimwip and in some cases pentachloride of phospliorus which nct upon many organic substances as if they were mixtures of terchlorides with free chlorine. I may illstance hcre the formation of Dutch liquid from olefiant gas and pentachloride of antimony according to WG hler aud the case of the transformation of bisulplde of carbon into chloride of carboii and chluride of sulphur by means of pentachloride of antimony mentioned by Hofmann.On comparing the action of pentachloride of aqtimony with that of chlorine in presencs of iodine upon the substances above mctitioncd I find that the fornier agent is rather more energetic and posscsscs a teridency to produce the higher chlorinated dcri- vatives. Bciizole adclcd in small qiiantitics to pentachloride of antimony is acted upon with great violence and there is at once formed a clilorinatecl derivative which crystallises in beautiful white prisms nearly insoluble in alcohol and not acted upon by alcohoiic potash. Succinic acid when brought in contact with pentachloride of antimony soon evolves hydrochloric acid and if the reaction is supprted by application of heat clilorosuccinic acid is formed.If however the mixture of succinic acid with pentachloride of airtinioiiy be kept warm whilst a current of chlorine is passing into it th succiriic acid is gradually decomposcd into volatile products. I am still engaged with the examination of some new products of these rcactions a full account of which I hope shortly to lay before the Society. Since tlie abovc was written I have found that together with the chloracetic acid there is invarialAj* some iodacetic acid formed and it appears that the for- mation of the latter is favoured by an exccs of iodine used in the proces. I have not ascertained wvhcthcr the remarkable compounds lately obtained by Schu tzen- bcrger by thc action of chloride of iodine upon acetate and benzoate of sodium are formed when clilorine acts ripon acetic and beozoic acid in the presence of iodine; but as thhe compounds are already decomposed at 100" C.their formation can hardly be expected under the circumstances.