422 FRANCIS : THE DI-NITROSAMINES OF ETHYLENEANILINE, X L. - The Di-nitrosamines o j E t h y leneaniline, the Ethylenetoluidines, and their Derivatives. By FRANCIS E. FRANCIS, Ph.D., B.Sc., Lecturer in Chemistry, University College, Bristol. 0. FISCHER and E. HEPP (Be?*., 1886, 19, 2992 ; Bey., 1887, 20, 1247, &c.) have shown that the aromatic nitrosamines, on treatment with alcoholic hydrochloric acid, yield paranitroso-derivatives. Thus nitroso- methylaniline, C,H,*N*CH,*NO, gives paranitrosomethylaniline hydro- chloride, NO*C,H,*NH* CH,,HCl. Should the para-position be already occupied, then, in the benzene derivatives, either no action takes place or the nitroso-group is removed, whereas in the naphthalene series the nitroso-group enters the ring in the ortho-position relatively to the substituted nitrogen atom.It was thought of interest to try whether similar changes took place in di-nitrosamines, and for this purpose those of ethyleneaniline and the ethylenetoluidines mere investigated. It was found that the molecular change is best brought about by a mixture of glacial acetic and concentrated hydrochloric acids, molecular rearrangement taking place rapidly and, if care be taken, the yields are good. If the para- position is occupied by a methyl group, decomposition occurs when the same treatment is adopted; the oiily substance capable of isolation is ethyleneparatoluidine, the nitroso-groups being removed. On the other hand, if the substitution is in the ortho- or meta-position, the molecular change takes place in the normal way.Tlie dinitroso-derivatives are easily reduced to the corresponding dianiines, that obtained from dini- trosoethyleneaniline yielding quinone on oxidation with potassium dichromate, showing that these substances are diamines of the type of ethyleneparaphenylenediamine. They give salts with 4HC1 corres- ponding to ethylenemetaphenylenediamine and ethyleneparamethyl- metaphenylenediamine prepared by Gattermann (Bey., 1884, 1’7, 779). They are very readily decomposed by nitrous acid, and give characteristic colorations with ferric chloride, They do not react with ketones, but readily condense with aldehydes, one molecule of the base acting on two of aldehyde.THE ETHYLENETOLUIDINES, AND THETR DERIVATIVES. 4% I. PaP.cccliniti.osoethyZe~ectniZine Hyclrochloi-itle, NO*CGH,.NH*C,H,.NH.C'GH,*N0,2HC1.This compound is prepared from the dinitrosamine of ethylene- aniline, C,H,[N(NO)-C,H,],, by dissolving it in about 5-6 times its weight of glacial acetic acid, adding half the volume of concentrated hydrochloric acid, and keeping at 60" with continual shaking for about ona hour. The nitrosamine, which separates out at first, gradually dissolves, and, on standing, the hydrochloride of the paradinitroso- derivative crystallises out almost completely. It forms a yellowish- brown, microcrystalline powder, which dissolves in water giving an intense yellow solution ; it is slightly soluble in alcohol and hot acetic acid, but insoluble in ether or benzene. The free base prepared from the salt is an orange-brown powder only very slightly soluble in the ordinary solvents.The following results were obtained on analysis. Found. Calculated. N = 15.93 16.32 per cent. HC1 = 20.84 21.28 ,, Et?yZenedipheny Zenepc~rccteti.ccmine, C,H,( NH C,H,* NH,),. Ten grams of the corresponding nitroso-derivative were reduced with excess of stannous chloride in concentrated hydrochloric acid. The tin double salt of the reduced substance separated out after each addition of the nitroso-compound to the cold solution ; this mas filtered off, and a solution of it in water decomnosd while hot with a slight ex- cess of potash solution ; on cooling, 4 grams of the substance separated in glittering plates. It is best recrystallised from water containing some potash, otherwise it rapidly becomes coloured. The melting point is 150".It is only slightly soluble in the ordinary solvents. Oxidised in the usual way with potassium dichromate, it gives a good yield of quinone (m. p. = 116"). The following results were obtained on analysis. C H N Found ......... 69-09 7.57 23.21 per cent,. Calculated ...... 69.42 7 4 3 23.14 ,, E t ~ y Z e l z e d i ~ l ~ n ~ Z e ~ p a i . ~ t e t r c L e Hyd~oc7~Zo~icle, NH,. C,H,*NH* C,H,*NH- C6H,,4HC1. When the base is dissolved in boiling water and excess of hydro- chloric acid added, the hydrochloride crystallises out in glittering plates on cooling. It is very soluble in water, but insoluble in hydro- chloric acid. Its solution is coloured intense blood-redwith ferric chloride, and dark red with potassium nitrite, decomposition taking place imme- G G 2424 FRANCIS : THE Df-NITROSAMINES OF ETBYLENEANILINE, diately even a t 0'.The same result is obtained using amylic nitrite and an alcoholic solution of the hydrochloride, but no cry stallisable pro- ducts could be isolated from the solution. Platinic chloride is partially reduced, and it was not found possible to isolate the double salt, even at low temperatures. A solution of the hydrochloride poured into a hot, strong solution of stannous chloride gives characteristic glittering prisms of the tin double salt on cooling. Found. Calculated. HC1 = 37.88 37-63 per cent. Ethylenetetracety Zdip~e~ay/enep6c?.c~tetrami~e, C,H,O *NH* C,H,*N( C,H,O)* C,H,*N(C2H,0)*C,H,*NH* C,H,O. On heating the ethyleneparaphenylen ediamine base with excess of acetic anhydride for some hours, the tetracetyl derivative is formed ; this can be isolated by neutralising the diluted solution with potash, when it is precipitated as a greyish, crysta,lline powder which may be recrystallised from nitrobenzene.It is insoluble in the ordi- nary solvents, but soluble in dilute acids. I t s melting point lies above 290". The following results were obtained on analysis. Found. Calculated. C = 64.06 64.39 per cent. H = 6.41 6-34 ,, Ethy ZenedibenxgZidenecliphenyZeneparatetrarnine, C,H,* CH :N* C,H,*NH C,H,- NH*C,H, N: C H*C,H,. When ethyleneparaphenylenediamine is warmed in benzene or alco- holic solution with benzaldehyde, action takes place immediately. I n alcohol, a yellowish powder is thrown down, which may be recrystallised from hot benzene, and is obtained in the form of pale yellow, silky needles melting a t 226-227'.It is very soluble in chloroform, only slightly so in boiling alcohol, and insoluble in ether or water. Warmed with dilute hydrochloric acid, it immediately takes up water, the base and benzaldehyde being regenerated. If it is suspended in alcohol, and alcoholic hydrochloric acid added, the solution becomes red, and an unstable hydrochloride is deposited ; this decomposes on warming, and cannot be isolated. Found. Calculated. N = 13.38 13.40 per cent. EthgZenedisa Zic ylidenecliplmy Zezneparcctetrarniw,e, OH C,H,*CH :N* C,H,'N H*C,H,*N H C,H,*N : CH* C,H,* OH. The action of salicylaldehyde on ethyleneparaphenylenediamine takes It is bed recrystal- place on warming the two in alcoholic solution.THE ET HPLENETOLUI DINES, AND THEIR DERIVATIVES.425 lised froin warm nitrobenzene, when it is obtained as small, orange- yellow plates melting at 224". It is but slightly soluble in alcohol, benzene, or chloroform, insoluble in ether or water, readily decomposed by dilute hydrochloric acid, and, like the benzaldehyde componnd, gives an unstable hydrochloride with alcoholic hydrochloric acid. Found. Calcnlated. c! = 74.37 74.66 per cent. H = 5.91 5-77 ,, 11. Diniti*osanz.ine of Etl~?lZe~zeoi'thotoZzcidine, C,H,[N(NO) 9 C,'H,* OH,],. Ten grams of ethyleneorthotolizidine are dissolved in alcohol, excess of hydrochloric acid added, and then sufficient acetic acid to keep all the hydrochloride in solution; on adding the requisite amount of nitrite to the ice-cold solution, the nitrosamine separates out as an oil which slowly solidifies.It can only be obtained pure with the greatest diffi- culty, as it is very soluble in all organic solvents. A small portion re- crystallised from dilute acetone, and afterwards washed with absolnte ether, gave a pale yellow, crystalline mass, melting between 94" and 95". The following nitrogen determination showed that it was not quite pure. Found. Calcnla tcd. N = 18.28 18.78 per cent. ~tl~ylenepa~.adinitro~o~.t~otolzcie Hydv-ochloyide, NO-C6H3(CH3)*NH* C,H,*NH* C6H,(CH,)*N0,2H01. Five grams of the above dinitrosamine were dissolved in 25 C.C. of glacial acetic acid, and 10 C.C. of concentrated hydrochloric added; on standing in a warm place for a few hours, 5 grams of the hydrochloride of the dinitroso-derivative separated as a greenish-yellow, crystalline powder which darkened on drying.It is soluble in water and alcohol, but insoluble in ether or benzene. Found. Calculated. HC1 = 19.44 19.67 per cent. Bt7~yle.ne~~o~~tl~otoZ~yle1ae~c,a~~atet~rcmine Hydrocldoi*ide, NH,* C,H,(CH,)*NH* C,H,* NH- C,H,( CH3)*NH,,4HCl. When the dinitroso-derivative is reduced with stannous chloride in concentrated hydrochloric acid, care being taken that the temperature is kept low, the tin double salt of the reduced substance separates out in crystalline masses. These are collected, dissolved in water, the solution decomposed by sulphuretted hydrogen, and the tin sulphide426 FRANCIS : THE DI-NITROSARIINES OF ETHY LENEANILINE, removed by filtration ; the filtrate containing the hydrochloride is now concentrated, and gaseous hydrogen chloride passed in until the whole of the salt has separated.It is obtained in small, glistening needles extremely soluble in water, the solution rapidly becoming intense blue on exposure to air. The solution in water gives the characteristic blood- red coloration with ferric chloride, also a red coloration and spontaneous decomposition with potassium nitrite. A solution of the salt when poured into a strong solution of stannous chloride deposits character- istic needles of the tin double salt. Alkalis precipitate the base as an oil which slowly solidifies on stmanding ; it is fairly soluble in water, ether, and alcohol. The analysis gave Found. Calculated. HC1 = 35.19 35.09 per cent.N = 13.80 13-46 ,, Ethyle nedibenxyZiclenec2ior~~Lotolzcy Zenepc~?.atetii~~i~~e, C,H,* CHIN* C,H,(CH,)*NH* C,H,*NH* C,H,(CH,)*N:CH* C,H,. If a solution of the base in alcohol is warmed for a few minutes with benzaldehyde, the condensation product is thrown down in large, yellow plates melting a t 175-176° ; it is very soluble in chloroform, slightly so in ether or alcoho1,”and can best be recrystallised from benzene and alcohol. It is decomposed by dilute acids into the base and benzalde- hyde, but forms an unstable hydrochloride in the same way as the ethyleneaniline derivative. Found. Calculated. N = 12.65 12.55 per cent. Et?LyZe.nemetutoZuidine, CH,* C,H,*NIX* C,H,*NH. C,H,* CH,. Metatoluidine and powdered sodium carbonate are heated together in an oil bath to 120Oin a flask fitted with a reflux condenser, the necessary amount of ethylenic dibromide is then added, and the whole heated for 20 minutes a t 150’ with continual shaking ; the reaction is then complete.The mass is treated with water, and the residual oil washed with dilute acetic acid to remove any metatoluidine unacted on; the product is then dissolved in twice its weight of alcohol, and after standing 3 days, the whole of the tertiary arnine, n,-dimetatolyl- piperazine, crystallises out. The hot alcoholic solution is then treated with an equal volume of concentrated hydrochloric acid, when, on cool- ing, the hydrochloride of the base separates in colourless needles ; this is insoluble in concentrated hydrochloric acid, dissociated by warm water, and can best be purified by recrystallis9tion from hot alcohol.It melts at128’. The yield is poor. The recrystallised hydrochloride gave the following figures on analysis.THE ETHYLENETOLUIDINES, AND THEIR DERIVATIVES. 42’7 Found. Calculated. HCl = 23.19 23.32 per cent. N = 8.80 s.95 ,, The free base is only obtained in the crystalline condition with con- siderable difficulty, The alcoholic solution of the salt is neutralised with alcoholic soda, and the sodium chloride formed is filtered off ; to the filtrate, a small quantity of tvat,er is first added, and then sufficient ether to dissolve the oil which separates. I n this way, flat plates slowly form, very soluble in the ordinary organic solvents, and melting at 58.5’. Found. Calculated. N = 11.50 11 -67 per cent. n-Dimetutoly~ipe~axine, CH,.c,H,*N<~~:: :::>”* c,H,* CH,. The tertiary amine formed in small quantities in the above prepara- tion crystallises from hot alcohol in flat plates melting a t 1 2 6 O , very soluble in ether, carbon, bisulphide, and benzene, but almost insoluble in cold aIcohol. Found. Calculated. N = 10.66 10.52 per cent. Dinitrosamine of Et7~yZenerr2etccto~u~~~~e, C,H,[N(NO) - C,H,* CH,],. The hydrochloride of ethylenemetatoluidine is dissolved in alcohol and treated with the necessary amount of potassium nitrite. The pro- duct crystallises in small, reddish-yellow plates, melts a t 1 1 2 O , and is very soluble in hot alcohol, almost insoluble in cold, soluble also in benzene, ether, and carbon bisulphide. Fonnd. Calculated.N = 18.90 18.78 per cent. E’thyZe~zedinzetutolu~lenepai~atet~ccnai?ze, C,H,[NH* CoH3( CH,) *NH,],. It is prepared in a similar way to the corresponding orthotoluidine derivative. The base is fairly soluble in hot water, from which it is obtained in the form of small plates on cooling. It gives a carmine-red coloration with ferric chloride, and a dark red solution and imme- diate decomposition with potassium nitrite, Platinum tetrachloride is reduced a t the ordinary temperature. It is very soluble in alcohol and hot benzene, almost insoluble in ether and carbon bisulphide, and can best be recrystallised from hot benzene or a mixture of benzene and ether. It melts a t 143’. Found. Calcul atcd. N = 20.85 20.74 per cent.428 WALKER AK’D LUMSDEN : DISSOCIATION-PRESSURE OF Biniti.osanzine of ~~l~~IenepcIratoluidine, C2H,[ (NO)N* C,jH,* CH,],, Ethyleneparatoluidine is dissolved in the necessary amount of hy- clrochloric acid, and to the cold dilute solution potassium nitrite is added ; the nitrosxmine is thrown down as a pale yellow, crystalline mass, which can best be recrystallised from chloroform and alcohol or from hot acetic acid. It melts a t 1 8 3 O , and is insoluble in alcohol and ether. Attempts mere made to reduce i t to the corresponding hydrazine, but in all cases the nitroso-groups were removed and ethyleneparatoluidine re-formed. When treated with a mixture of acetic and hydrochloric acids in the may previously described, the hydrochloride of ethylene- tolaicline was the only substance that could be isolated. Found. N = 18.82 Calcnla ted. lS.77 per cent. By the kind permission of Professor Campbell Brown, mostl of the above work mas carried out in the Research Laboratory of University College, Liverpool.