2'770 FORSTER AND SCHLAEPFER :CCLIX.-Studies in the Camphane Seeies. Pay-tX X X VI. N- Chloroaminocamphor.By MARTIN ONSLOW FORSTER and MAX SCHLAEPFER.THE subject of this commurication was produced unexpectedly asthe result of attempts to shorten the process for obtaining a-triazo-camphor (camphorylazoimide), the original method (T., 1905, 87,826) being too circuitous far ordinary application.The possibility of replacing the halogen in a-chlorocamphor anda-bromocamphor by heating these materials with sodium azide wasfirst tested, without success, when Raschig's description of a simplemethod for preparing hydrazine (D.R.-P. 198307; A., 1908, ii,1029) suggested the production of camphorylhydrazine, from which,by the action of nitarous acid, camphorylazoimide should arise onthe principle rendered familiar by Curtius.On adding aqueouschloroamine to dissolved aminocamphor, however, a colourless solidwas precipitated, and instead of having the properties to beexpected of camphorylhydrazine, was found to consist of N-chloro-aminocamphor. There remained a possibility of arriving a tcamphorylhydrazine by the action of ammonia on the chloroamine,but experiment showed that the removal of hydrogen chloridetakes place in such a way as to produce iminocamphor, f o r thepreparation of which substance a very convenient method has thusbeen brought t o light:The reaction, in fact, is directly comparable with that by whichiminocamphor was obtained originally :the wrenching away of two atoms-nitrogen alone in the case oftriazocamphor, hydrogen and chlorine in the case of AT-clilnro-aminwamphor-so disturbing the affinity relations of the resid a a 1nitrogen as to cause migration of hydrogen from the neighbouringcarbon.The alternative explanation :iH C1:was tested by the preparation of camphorylacetyl nitrogen chloride(aceto-AT-chloroaminocamphor) and treatment of this conipoundwith ammonia, which Id simply to the regeneration of acetoSTUDIES IN THE CAMPHAKE SERIES. PABT XXXVI. 2771aminocamphor instead of aceto-iminocamphor, or camphorquinoneand acetamide.Although not the first representative of its class, the simplestmember, methylchloroamine, having been prepared in 1893, webelieve that chloroaminocamphor is probably the first materialof this type to be obtained in crystalline form, and, as might beanticipated, it is a very active and unstable substance, oxidisinghydrogen iodide and sulphurous acid in the manner of an acylatedaryl or alkyl nitrogen chloride.It rapidly undergoes a spontane-ous change, the undissolved material being transformed in thecourse of a few hours into a honey-like mass, whilst solutions inhydrocarbons quickly deposit aminocamphor hydrochloride, andcontain t.ha anhydride of cyanolauronic acid together withuncrysiallisable products. I n acetone the chloroamine also changesinto aminocamphor hydrochloride, accompanied by a crystallinecompound (m. p. 155O) having the composition c16Hz30N; this hasnot been identified with any known compound, but the equation :C,,HI6ONC1 + Zc3H60 = HCl + 2H,O + C,,H,,ON,would account for a product having this empirical formula.Whilst ammonia converts chloroaminocamphor into imino-camphor, aromatic amines are oxidised by the substance, whichtakes hydrogen from the amino-group and passes into amino-camphor hydrochloride.Thus aniline yields azobenzene :whilst phenylhydrazine loses its nitrogen.During a few days’ suspension in water, the chloroamine changesinto a crystalline material melting a t 95O, along with amino-camphor hydrochloride. The new compound, which is producedalso when chloroaminocamphor is dissolved in sulphuric acid, islikewise a derivative of nitrogen chloride, and is related to cam-phoric imide, yielding that substance when heated a t looo.Owingto its unstable character, and the consequent difficulty attendinganalysis, we cannot be certain of the empirical formula, althoughCl,Hl6O2NCl,H,O is indicated.EXPERIMENTAL.CH*NHClco N-Chloroaminocamphor, C,Hl,< IAn acid solution of aminocamphor hydrochloride prepared from25 grams of isonitrosocamphor, as already described (T., 1905, 872772 FORSTER AND SCHLAEPFER :113), was chilled with ice and treated with chloroamine from330 C.C. of a sodium hypochlorite solution (containing 32 grams ofavailable chlorine per litre) and 6 C.C. of ammonia (0.88) dilutedto 50 C.C. The solution remained alkaline to litmus, whilst acolourless oil separated immediately and rapidly solidified. Afterthree hours in ice, during which period separation of the chloro-amine was complete, the substance was collected, roughly driedon earthenware, and for all ordinary purposes was used in thisform, 20 grams being the amount usually obtained.As the substance is extremely unstable, purification and analysismust be completed in one day.Such specimens were prepared bymixing the ingredients overnight, leaving the suspended productin the icechest, and filtering early the following morning; theroughly dried material was immersed in cold petroleum (b. p.40-50°) in quantity insufficient for dissolution, and then shakenwith calcium chloride, the amount of which may be gauged t odevelop with thO associated water enough heat to dissolve theexcess of the chloroamine without perceptibly raising the tempera-ture of the solution. This was filtered and rapidly evaporatedunder diminished pressure, when there separated radial aggregatesof colourless needles melting a t 43O and decomposing violentlya t 85O:0.2720 gave 0.6012 CO, and 0.1976 H,O.C = 60.3; H =8*1.0.3042 ,, 18.8 C.C. N, a t 23O and 758 mm. N=7-0.0.2641 contained 0.0442 available chlorine.C,,H,,ONCl requires C = 59.6 ; H = 7.9 ; N = 6.9 ; C1= 17.6 per cent.Chloroainiiiocamphor is sparingly soluble in cold water, but dis-solves very freely in all organic media; it liberates iodine fromaqueous potassium iodide immediately, but before titrating theliquid with sodium thiosulphate it is better to add alcohol and afew drops of glacial acetic acid. Even the purified compoundcannot be preserved, because i t changes in the course of a fewhours to a yellow resin, liberating chlorine and hydrogen chloride;this alteration takes place alike, whether i t is exposed t o the airo r situated in a desiccator containing soda-lime, and occurs alsoif the material is widely and loosely distributed.Although the conditions of preparation appear t o preclude thepossibility of the foregoing substance being the hypochlorite ofaminocamphor, the hydrochloride of the base was mixed in aqueoussolution with sodium hypochlorite alone; this precipitated an oilwhich did not become solid, and which underwent explosive decom-position even while suspended in water.Action of So&um SuZphite.-The simple relation between thechloroamine and the original base is established by the regenera-C1= 16.7STUDIES IN THE CAMPHANE SERIES.PART XXXVI. 2’7’73tion of the latter under the influence of sodium sulphite. Whenfreshly prepared chloroaminocamphor is immersed in a solution ofthe salt, the hard granules rapidly become pasty and afterwardsoily, tho odour of sulphur dioxide being noticeable. With furtherlapse of time the oil disappears, leaving a small proportion ofcamphorquinone , whilst the main bulk of the chloroamine isrepresented in the filtrate by salts of aminocamphor.Decomposition in Benzenw-Solutions of the chloroamine inorganic media change a t various rates, and always yield amino-camphor hydrochloride. Thirty-f our grams of freshly prepared,roughly dried chloroaminocamphor were dissolved in 100 C.C.ofbenzene, dried with calcium chloride, filtered and left in a desic-cator containing soda-lime. I n the course of a few hours amino-camphor hydrochloride began t o separate in colourless needles,increasing with passage of time until about 14 grams had accumu-lated after the lapse of nearly nine weeks; meanwhile the air inthe desiccator liberated iodine from potassium iodide, and thesolution remained active during more than four weeks. On evapor-ating the filtered benzene there was deposited a bright yellow,Iioney-like mass, and although tliis weighed more than 1 2 grams,oiily about 1 gram of cryst.alliiie material was obtained from it.A small proportion of tliis was camphorquinone, separated bykneading the honey successively with small quantities of lightpetroleum, which dissolved that substance ; the residue becamehard and granular, and on being dissolved in a very small quantityof hot methyl alcohol was deposited slowly in colourless crystals,which, on recrystallisation from the same solvent, formed colour-less plates melting a t 1 7 4 O (Found, C-69.3; H=8*3; Nz8.3.C,,H,,O,N, requires C = 69.8 ; H = 8.1 ; N = 8.1 per cent.).Thecompound was thus identified as the anhydride of cyanolauronicacid.The change which chloroaminocarnphor undergoes in petroleumfollows the same course, yielding aminocamphor hydrochloride anda small proportion of the anhydride of cyanolauronic acid.llecomposition in Acetone.-Fifty grams of the chloroaminewere dissolved in 50 C.C.of acetone a t zero, the liquid slowly becom-ing brown. After twelve hours in the ice-chest a heavy, almostcolourless oil had separated, and as this did not, dissolve on adding25 C.C. more acetone the liquid was set aside during one week,when it became homogeneous and much darker, whilst 7.3 gramsof pale brown crystals separated. The filtrate affected the eyes inthe manner of chloroacetone, and did not deposit more solid aftersix weeks a t zero; it was therefore diluted largely with water,which precipitated a brown tar, and from this, by rubbing wit2774 FORSTER AND SCHLAEPFER :cold methyl alcohol, a furt,her 2 grams of crystalline material wasrecovered. On treating the accumulat'ed solid with aqueous alcohol(1: 1), 3.5 grains remained, and the filtrate contained amino-camphor hydrochloride.The solid residue dissolved freely in boil-ing alcohol, and crystallised in lust'rous, very pale brown needles,melting a t 155O:0207G gave 0.5931 CO, and 0-1723 E20.0.1917 ,, 9.9 C.C. N, a t 23O and 763 mm. N=5.8.C,,H,ON requires C = 78.4 ; H = 9.4 ; N =5*7 per cent.The substance is freely soluble in benzene o r ethyl acetate, anddissolves readily in boiling petroleum, from which it is conveni-ently crystallised.Action of A mmonia.-Freshly prepared chloroaminocamphorwas covered with ammonia (0.88) and stirred a t intervals, becomingoily in less than one hour, afterwards changing to a hard cake ofiminocamphor ; as this substance is extremely unstable, and cannotbe recrystallised, it was ident'ified (1) by quantitative conversioninto csmphorqninone and ammonia, and (2) by the characteristicmagenta coloi ation developed with formaldehyde and sodiummethoxide (T., 1908, 93, 250).,4 ction of Amines.-As already stated, the foregoing experimentwas made with the object of preparing camphorylhydrazine, andthe result was totally unexpected.The action of various amineswas therefore studied, but the most definite result was obtainedwith aniline. Nine grams of chloroaminocamphor were dissolved inether, and having been dried with calcium chloride, the solutionwas mixed with 8 grams of aniline. On the following day, 2 gramsof aminocamphor hydrochloride were reiiioved by filtration, andthe dark brown liquid, when freed from ether, was treated withdilute hydrochloric acid to remove excess of aniline.The residualtar became harder when rubbed wit$h a small quantity of alcohol,and having been drained from the latter, was extracted with lightpetroleum, which deposited azobenzene 011 evaporation.When treated under similar conditions with diphenylamine amixture of aminocamphor hydrochloride with ammonium chlorideseparated, and these salts were precipitated also by a-naphthyl-amine, but azonaphthalene could not be identified in the darkbrown, viscous material deposited by the filtrate. With phenyl-hydrazine the action was extremely violent a t the ordinary tem-perature, but on mixing dilute ethereal solutions of the twomaterials at zero very slowly, aminocamphor hydrochloride wasprecipitated and a steady liberation of gas took place.9 ction of Water.-Ten grams of cliloroaminocamphor werecovered with about 30 C.C.of water and stirred a t intervals. AfterC = 78.1 ; H = 9.3STUDIES IN THE CAMPHANE SERIES. PART SXXVI. 2’7’75three days the substance, at first granular and dense, had swolleninto the liquid and had become soft; the following morning it hadbecome dense again and very hard, whilst flat, colourless needleswere suspended in the pale yellow liquid. The solid weighed5 grams, whilst the filtrate, after extraction twice with ether t oremove a very small quantity of camphorquinone, deposited onevaporation 4 grams of axninocamphor hydrochloride mixed witha very small proportion of ammonium chloride.Meanwhile thecolourless crystals, a less inipure form of the hard, granular mass,were found to set free iodine from potassium iodide, and whendissolved in ethyl acetate, using the device already adopted inthe case of chloroaminocamphor, petroleum precipitated flat, colour-less prisms in stellate aggregates. Newly crystallised, the substancemelted a t 95O, evolving gas, but when preserved in a desiccatorcontaining soda-lime, it changed into a material which melted a t2 2 7 O , did not liberate iodine from potassium iodide, and whendissolved in hot water gave the imide of camphoric acid (ni. p.245O); the latter is produced also when the substance is heatedat looo, chlorine being liberated :0.2008 gave0.3887 CO, and 0.1471 H20.0.1822 ,, 9.3 C.C.N, a t 18O and 771.5 mm. N=6*0.0.3460 contained 0.04985 available chlorine. C1= 14.4.C=52*8; H=8*1.C,,H,,O,NCl,H,O requires C =51*1; H = 7.7 ; N = 6.0 ;Cl= 15.0 per cent.We ascribe the indeterminate result of this analysis t o the diffi-culty of removing the last traces of petroleum in a substance,wliich, owing t o its excessive instability, must be analysed immedi-ately. The compound is freely soluble in organic media, but differsfrom chloroaminocaniphor by its sparing solubility in cold petrol-eum. It is also produced when chloroaminocamphor is dissolvedin concentrated sulphuric acid ; 10 grams of the freshly preparedmaterial were added in small quantities t o 50 C.C. of icecold acid,which was shaken vigorously during the process, chlorine beingliberated. After half-an-hour, when effervescence ceased, the liquidwas poured on crushed ice, which precipitated a colourless oil,rapidly solidifying; the product weighed 3.3 grams, and whenrecrystallised from acetone diluted with water formed lustrousneedles melting a t 95O.CH*NCi*CO*C!H,N-Chloronceto-aminocamphor, CI,U,,<~!,The finely powdered acetyl derivative of aminocamphor wassuspended in aqueous sodium bicarbonate a t zero, and treatedwith an ice-cold solution of sodium hypochlorite; after twelvehours the product was filtered, washed, and dissolved in cold methy2’7’16 FRIEND AND MARSHALL : THE CORROSION OF IRON AND ITSalcohol, from which water precipitated lustrous, silky needles,melting a t 7 8 O :0.1500 contained 0*0218 available chlorine.G,,R,80,NCl requires C1= 14.5 per cent.The substance’ is freely soluble in petroleum, acetone, or methylalcohol, and liberates iodine from potassium iodide immediately.Ammonia does not transform it into aceto-iminocamphor, butmerely regenerates the acetyl derivative of aminocamphor.I n conclusion, we desire t o express our thanks to the Managersof the Royal Institution for their courtesy in placing a laboratoryat our disposal.C1= 14.5.TEE DAVY-FARADAY LABORATOI:YOF THE ROYAL INSTITUTION, W