THE N-BUTYLARYLAMJNES. PART 111. 176 YX.-The n- Butylm-ylamines. P a ~ t III. Constitu-tion of the Nitro-derivatives of n-Butyl-p-toluicline. By JOSEPH REILLY and WILFRED JOHN HICKINBOTTOM. IN Part 11. of this series (T. 1918 113 985) the preparation of 2- and 3-nitro-n-butyl-p-toluidiiies was described and in the pre-sent paper an account is given of the products of reduction of these nitro-compounds the study of which has shown that the constitu-tions previously assigned tmo them are correct. The 3-nitro-derivativeJ on reduction furnishes 3 4-toZylene-4-N-n-butyldiamine (I) which is a readily oxidisable oil and the corre-sponding 3-nitroacetyl derivative gives 2 5-dimethyLl-n-butyl-benzirninazole (IP) which is also obtained by the action of heat on 4acetyl-3 4-toly/lene-4-N-n-butyldiam,ine (111).N H*C,H N( C,H J. Me NAc*C,H, (',NB, \/ CH, (7% PI-" \/ CII CH3 (111.) (1.1 (11.1 I" 176 REILLY AND HXUKINBOTTOM : The coiistitution of 3 5-dinitr0-72rbutyl-ptoluidine is proved by th0 fact that on hydrolysis with sodium hydroxide itl yields n-butyl-amine and 3 5-dinitro-p-cresol. By the action of acids or direct sunlight on 3 5-dinitreptolyl-n-butyl-nitro- or -nitroso-amine tho dinitro-amine is regenerated, and the nitroarnine is similarly decomposed on boiling it with ethyl or n-butyl alcohols. When the nitroarnine is hydrolysed by sulphuric acid or sodium hydroxide nitrous acid is formed. EXPERIMENTAL. *H, \-/ 2 4 - ~ o ~ y ~ e n e 4 - ~ - n - but?y~diarnine CH / \NH=c~H,. 2-Nitro-n-butyl-p-toluidine (3 grams) was mixed with 10 C.C.of concentrated hydrochloric acid and 40 C.C. of water and zinc dust (4 grams) gradually added. Excess of zinc was removed from the colourless solution and the amine was isolated by the addition of sodium hydroxide solution followed by extraction with ether. It formed a pa10 brown powder which was purified by solution in dry ether and precipitation wit'h light petroleum. A white floccu-lent mass was obtained which on drying could easily be powdered. By spontaneous evaporation of t5he ethereal solution it' was obtained in colourless needles melting a t 5 3 O : 0.0956 gave 12.9 C.G. N a t 19.2O and 750 mm. Ci,H,,N2 requires N = 15.72 per cent. 2 4-ToZyle.ne-4IN-n-butyZ~~amine is soluble in most of the common organic solvents sparingly so in water and very sparingly so in light petroleum.With ferric chloride solution it gives a very faint brown coloration which however is not very character-istic. It gives no characteristic colour with nitrous acid or potassium f errocyanide. The hydrochloride is very readily soluble in water. 4-A cet?/Z Derivative ,-Tin foil was added to 2-nitroaceto-n-butyl-p-toluidide (1 mol.) suspended in concentrated hydrochloric acid (6 mols.) until reduction was complete. The sdut-ion was filtered, diluted with water and the tin removed by means of hydrogen sulphide. The filtrate was rendered alkaline and the amine isolated as a brown oil by extraction with ether. It solidified to a mass of brown crystals which on crystallisation from a mixture * In the nitrogen estimations recorded in this paper the gas was collected over 40 per cent.potassium hydroxide solution. A correction has been introduced for the vapour tension of the potassium hydroxide solution. N=15*56. THE N-BUTYLARYLAMINES. PART 111. 177 of ether and light petroleum was obtained in white crystals melt-ing a t 98-99O: 0.0723 gave 8.1 C.C. N a t 20° and 749 mm. The compound dissolves in ether and many of the other organic solvents but is insoluble in light petroleum. The diazo-compound gives with &naphthol a brownish-red mo-dye which dissolves in sulphuric acid with the development of a deep purple-red colora-tion changing to pale brown on dilution. The @cmte of the base crystallises from alcohol in groups of yellow needles melting at 185O.N=12*87. C13H200N requires N = 12-72 per cent. 3 4-Tolylene-4-N-n-butyldiamine. The reductioa od 3-nitro-n-butyl-p-toluidine in the way described f o r the 2-nitro-compound yields the corresponding diamine as an oil which is white when first precipitated but rapidly acquires a deep blue colour and ultimately becomes almost black: 0.1211 gave 16.2 C.C. N a t 2 2 O and 764 mm. C,,H,,N requires N = 15-72 per cent. The compound is readily miscible with most of the ordinary organic solvents. The hyd?-ochZoyide was obtained by passing a dream of dry hydrogen chloride into a solution of the base in dry xylene. The bulk of the xylene was decanted and the rest removed by washing with light petroleum. After being dried at looo the salt formed a white powder.J t is extremely deliquescent) and very readily soluble in water: N=15.57. 0.0552 gave 0.0625 AgCl. C1=28*0. The aqueous solution is very readily oxidised. CllH1,N,,2HC1 requires C1= 25.2 per cent. One drop of ferric chloride solution produces an intense blood-red or deep brown colour. A dilute solution of chromic acid o r a very dilute neutral solution of potassium dichromate produces a brownish-black or black solution depending on the concentration of the oxidising agent. An aqueous solution of bleaching powder yields a deep blue solution. Nitrous acid in dilute solution gives a dirty purple coloration whilst coacentrated nitric acid also gives a purple coloration. The 3 4-diacetyl derivative was prepared by warming the base with acetic anhydride.A dark-coloured oil was obtained which slowly solidified to a mass of dark brown crystals. By repeated crystallisation from a mixture of light petroleurn and acetone o 178 REILLY AND HICKINBOTTOM: from hot dilute aqueous alcohol it was obtained in white crystals melting at 130O: 0.0754 gave 7.1 C.C. N a t 25O and 7'48 mm. The compound is moderately soluble in hot but sparingly so in N=10-62. C,,H,O,N requires N = 10.69 per cent. cold water. 4-A cet yl-3 4-tolylene-4-N-n- butyldiamine (111). 3-Nitroaceto-n-butyl-p-toluidide (4 grams) was dissolved in 50 C.C. of aqueous alcohol (70 per cent.) containing iron filings (10 grams) and to the mixture warmed to 30° glacial acetic acid was slowly added the temperature being kept a t 30°. After an hour the mixture was heated on the water-bath the unchanged iron remo'ved by filtration washed with warm dilute acetic acid, and the filtrate rendered alkaline and heated a t 80° for several hours.The base was extracted with ether and purified by re-crystallisation from a mixture of equal parts of dry ether and light petroleum when it was obtained i n short colourless needles melting a t 102O: 0.0702 gave 8-0 C.C. N2 a t 21° and 738 mm. C13H2,0N requires N = 12.72 per cent. The compound is readily soluble in alcohol ether benzene or carbon tetrachloride but very sparingly so in light petroleum. The diazo-compound gives a red azo-dye with P-naphthol. On heating the base in a flask fitted with a short air condenser a t 200° in an oil-bath globules of water were observed in the con-denser.After heating f o r four to five hours the dark viscous residue was distilled over a free flame when a pale yellow oil was obtained which did not solidify a t Oo and was not a primary amine. From its method of formation it is probably 2:5-&methyZ-l-n-butylbenziminazole (11). The same compound was produced by the vigorous reduction of 3-nitroaceto-m-butyl-p-toluidide in acid solution. The nitro-compound (5 grams) was dissolved in a mixture of glacial acetic acid. (25 grams) concentrated hydrochloric acid (10 grams) and water (15 c.c.). Zinc dust (20 grams) was added, and the solution became very warm. After the reaction had moderated and more zinc dust had been added the solution was heated on the sand-bath for one or two hours.After removal of the excess of zinc the solution was rendered alkaline with potassium hydroxide solution and the precipitated oil extracted with ether. N=12*85 THE N-BUTYLARYLAMINES. PART 111. 119 On distillation it was obtained as a very viscous pale yellow oil boiling a t 335-338O : 0.0746 gave 0.2115 CO and 0.0606 H,O. 0-0794 , 9.9 C.C. Nz a t 23.1" and 736 nun. N=13*92. 2 5-Dimethyl-1 -n-butylbenziminazale is miscible with ether or alcohol. When exposed in an open dish to a moist atmosphere it readily absorbs water and oxygen gradually becoming darker. By the act,ion of an aqueous-alcoholic solution of picric acid on the alcoholic solution of the anhydro-base the picrate was precipitated ; t.his crystallised from acetone in short, yellow needles or prisms melting a t 209O: C=77*34; H=9*09.C13H18N2 requires C= 77.18 ; H= 8.97 ; N = 13-85 per cent. 0,0756 gave 10-7 C.C. N2 a t 2 1 O and 749 mm. It is practically insoluble in water ether or alcohol. N=16.20. Cl,H,,N,,C,H,O,N requires N = 16.24 per cent. Action of Alkalis o n 3 ; 5-Dinitro-n-butyl-p-toluidine. The dinitro-compound (1 gram) was heat'ed under reflux with a solution of 5 grams of potassium hydroxide i n 40 C.C. of water for six to eight hours. The colour of the solution changed rapidly through brownish-red to very dark red or almost black. On dis-tillation into dilute hydrochloric acid n-butylamine hydrochloride was obtained. The alkaline residue in the flask after being cooled and filtered was acidified with dilute sulphuric acid and from the ethereal extract a solid cryskallising in yellow needles (m.p. 8 2 O ) was obtained which proved to be 3 5-dinitro-p-cresol. Action of Acids on 3 5-ninitroip-t~lyl-n-h2Lt?/l-nitroam~.ne and -nitrosoarnine. 3 5-Dinitro-p-t~lyl-n-butylnitroamine (0.5 gram) was dissolved in 2 C.C. of concentrated sulphuric acid (97 per cent.) the solution being kept cod by immersion in ice-cold water. The nitroamine dissolved slowly with the production of a deep reddish-purple colour which changed finally to yellow. After half an hour the mixture was poured on ice when a yellow solid was obtained, which proved to be the colrresponding nitrosoarnine. Nitrous acid was also found to be present. In another experiment 50 C.C. of slightly warmed sulphuric acid (90 per cent.) were added t o the nitroamine (0.5 gram).There was a faint d o u r of nitrous acid, and the colour changes were the same as those described above 180 REILLY AND HICKINBOTTOM : After remaining for twenty days exposed for part of the time to sunlight the colour had changed to deep red. On pouring into water and extracting with ether 3 5-dinitro-n-butyl-p-hluidine was obtained as the chief product. Further the nitroarnine (0.5 gram) was heated under reflux with a mixture of concentrated hydrochloric acid (20 c.c.) and n-butyl alcohol (50 c.c.) for eight hours. The colour of the mixture gradually became darker until it was finally a deep red. After removal of the alcohol a red sub-stance melting indefinitely a t 65-80° was obtained. The melting point was raised to 86-88O by treatment with amyl nitrite in the presence of hydrochloric acid the colour also becoming considerably paler.On warming the nibroarnine with an aqueous solution of per-chloric acid and allowing the mixture t o remain for twelve hours, a slight darkening occurred. The action of glacial phosphoric acid in the cold produced practically no colour change after a week. 3 5-Dinitro-p-tolyl-n-butylnitrosoamine by the action of hydro-chloric acid containing some aniline hydrochloride yields the corre-sponding amine in almost quantitative yield and in a pure condi-tion (compare Pinnow Ber. 1897 30 838). The nitrosoamine (2.4 grams) was heated under refiux for eight hours with alcoholic hydrogen chloride (50 c. c.) containing aniline hydrochloride (1 gram).On evaporating the alcohol 2.1 grams of 3:5-dinitro-n-butyl-ptoluidine identified by the mixed melting-point method, were obtained. When the aniline hydrochloride was omitted the reactioq followed a similar course but required a longer time for completion. Action of Alkalis on 3 5-Dilz/itl.o-p-tol~I-n-bwtyl-nitrolamine m d Izitrosoaminc . Alcoholic potassium hydroxide reacts with alcoholic solutions of the nitroarnine and nitrosoarnine with the production of a dark purple colour which gradually deepens in intensity. In aqueous solution the reaction takes pIace much more slowly. 3 5-Dinitro-p-tolyl-n-butylnitroamine (1 mol.) was heated under reflux with a large excess of a 10 per cent. aqueous solution of sodium hydroxide (15 mols.). The nit,roamine was slowly attacked yielding a purple solution which gradually became almost black when the reaction was considered to be complete.On distillation n-butylamine was obtained. The alkaline residue in the flask which contained sodium nitrite was diluted and after filtering rendered acid in the presence of carbamide to remove nit'rous acid. On extractio THE N-BUTYLAFtYLAMLNES. PART 111. 181 with ether a pale brown oil was obtained which solidified to a yellow crystalline solid. After several crystallisations from aqueous alcohol this melted a t 82* and was shown to be 3:5-di-nitro-p-cresol. When either the nitroarnine or the nitrosoamine was heated with two or three times its weight. of phenol a t 180° and the pro-duct treated with very dilute ice-cold sodium hydroxide solution, f dlowed by extraction with ether 3 5-dinitro-m-butyl-ptoluidine was obtained in good yield and the same result was obtained by heating the nitroarnine or nitrosoamine with a large excess of n-butyl alcohol or ethyl alcohol for several hours in diffused light.Both the nitroamine and nitrosoarnine were finely powdered and exposed in glass and quartz vessels to direct sunlight. After one hour the nitrosoamine had deepened considerably in colour and the melting point was depressed. The nitroarnine on the other hand changed colour only slowly but there was sufficient action in both cases after one montlh’s exposure to detect the presence of 3 5-dinitro-.n-butyl-p-toluidine. In some of the reactions where the decomposition was not complete the melting point alone was not a sufficient guide to determine the cornpositdon of the product. The colour affords an indication of the production of the parent arnine and this was confirmed by the evidegce obtained by the action of amyl nitrite and of nitric acid. I n the decomposition of the nitrosoarnine or of the nitroarnine the production of the parent amine was assumed to have occurred when the action of amyl nitrite or nitrous acid in t’he presence of hydrochloric acid or acetic acid effected a considerable loss of colour and when the melting point was altered. The action of fuming nitric acid in giving a product identical with the original nitroamine showed that the butyl group had not been removed and that only the nitroso-group linked t o the aminic nitrogen atom had been affected. [Received January 16th 1919.