1026 REILLY AND HICKINBOTTOM : LXXXI X .- Derivatives of n- But ylaniline. By JOSEPH HEILLY and WILFRED JOHN HICKINBOTTOM. THE lower nlkylanilines have for a long period been recognised as of considerable technical importance and with their derivatives have been subjected to very detailed investigation. On the other hand, the higher alkylanilines and phenylenealkyldiamines generally have been but little examined and it is only quite recently that such compounds as p-nitrosodipropylaniline pphenylenedipropyldiamine (Jacobs and Heidelberger J. Bid. Chem. 1915 21 103) and pphenyleneisoamyldiamine (Karrer Ber. 1915 48 1398) have been subjected t o any thorough study (compare also Mandl, Monatsh. 1886 7 99; Baeyer and Noyes Ber. 1889 22 2173). I n the case of the n-butyl compounds but few derivatives have been prepared.By oondensing 12-butyraldehyda with aniline Kahii (Ber. 1885 18 3361) obtained n-butylaniline and from it the nitrosoamine the acetyl compound and the hydrochloride but no other references to n-butylaniline or its derivatives have been found. I n the present work the condensation of n-butyl chloride and aniline has been investigated and several of the derivatives of n-butylaniline have been prepared and their properties investigated. I n the reaction between n-butyl chloride and aniline it was found that mono-n-butylaniline was the chief product when these com-pounds were heated together under atmospheric pressure. A frac-tion of higher boiling point was found to consist mainly of di-n-butylaniline. The crude mixture of bases resulting from the reaction was dis-tilled and thus partly separated into aniline n-butylaniline and di-n-butylaniline.The n-butylaniline fraction was converted into phenyl-n-butylnitrosoamine (I) which was reduced to as-phenyl-N(C,H,)*NO N(C,=S)*NH N( C,H9)*N :N*N(C,H,) /\ /\ /\ /\ I I - + I 1 - + I I t \/ (111.) \/ (11.1 x NH C,H NH*C,H V,H,)*NO /\ + \ I - 1 I \/ ‘ G ) \ \/ /\ ‘h6 NO 0 \/ NH2 (V. ) (IV.1 (VI. DERIVATIVES OF N-RUTYLANILINE. 1027 n-butylhydrazine (11) and this compound was 6hen oxidised to diphenyldibutyltetirazone (111) by the action of yellow mercuric oxide in ethereal solution : By means of Fischer and Hepp’s reaction (Rer. 1886 19 2991; 1887 20 1247) the nitrosoamine was converted into p-nitroso-n-butylaniline (IV).On keeping the crude hydrochloride darkened, owing probably t o the presence of free hydrogen chloride behaving similarly t o p-nitroeoisobutylaniline hydrochloride (Walker Anna-l e i ? 1888 243 298) p-Nitroso-n-butylaniline was easily reduced by means of zinc dust and hydrochloric acid to the corresponding diamine (V). The nitrosoamine is also decomposed into p-nitroso-phenol and n-butylamine thus confirming its constitution. It is converted into p-nitrosophenyl-?t-butylnitrosoamine (VI) by the action of nitrous acid. Whilst p-nitrosomethylaniline hydrochloride separated almost quantitatively in Fischer and Hepp’s reaction (Zoc. c i t . ) from solu-tion in a mixture of alcohol and ether p-nitrosobutylaniline hydro-chloride under similar conditions gave only a small precipitate (compare Walker Annnlen loc.c i t . ) . A yield equal t o 75 per cent. of the weight of nitrosoamine taken is obtained by substituting a solution of hydrogen chloride in butyl alcohol for the ethyl-alco-holic solution and reducing the proportion of alcohol t o ether by one-half. pPhenylene-77-butyldiamine resembled the other known mono-substituted ~~plien~lenediamines in being readily oxidised t o p-benzoquinone and in yielding colour reactions with ferric chloritle and nitrous acid (compare Fischer and Wacker Rer. 1888 21, 2614; Jacobson Annalen 1895 287 131 ; Bamberger Ber. 1898, 31 1516; Bernthsen and Goske Ber. 1887 20 929). E x P E R I M E N T A L. n-Butylaniline was prepared by heating one molecular proportion of aniline (93 grams) with slightly more than one molecular pro-portion of n-butyl chloride (100 grams) fo,r thirty-six hours on a water-bath using a reflux condenser.A crystalline deposit was pro-duced which after the liquid had been filtered off was shown to be mainly aniline hydrochloride with a small amount of n-butylaniline hydrochloride. From the reddish liquid poured off the crystalline deposit uncombined n-butyl chloride was removed by distillat.ion and the residual oil treated with sodium hydroxide solution. The bases which separated were extracted with ether the ethereal layer was left in contact with potassium carbonate for some time and the solvent removed by evaporat,ion ; the oil obtained was then distilled. At first’ some n-butyl chloride mixed with aniline distilled ove 1028 REILLY AND HICKINBOTTOM : below 180°.The fraction 1 80-200° contained n-butylaniline mixed with aniline and the distillate between 200° and 250° was n-butylaniline mixed with a smaller amount of a d i n e . There was also a fraction boiling a t 250-275O which was found to consist chiefly of di-72-butylaniline ; this was investigated later. The distil-late boiling a t 200-250° on redistilling gave a large fraction a t 240-245O and by a further redistillation this gave a fraction boil-ing a t 242-244O/765 mm. By converting the latter fraction into the nitrosoamine and reducing with zinc dust and warm glacial acetic acid n-butylaniline was obtained free from traces of the dialkyl compound. It boiled a t 241-242O/752 mm.(Kahn gives 235O/720 mm.) The fraction boiling between 200° and 250° from the original experiment with aniline and ?z-butyl chloride was not further frac-tionated for subsequeat experiments for the action of nitrous acid made i t possible to separate the mono-n-butylaniline from aniline and di-n-bntylaniline. Tlie fraction boiling between ZOOo and 250° (105 grams) was therefore dissolved in an excess of dilute hydro-chloric acid and a concentrated aqueous solution of sodium nitrite was slowly added until the yellow turbidity changed to red. The nitrosoanline separated on top of the aqueous solution as a reddish-yellow oil which was extracted with ether the ethereal solution being washed with sodium hydroxide solution and finally with water. From the separated ethereal layer dried over potassium carbonate the solvent was evaporated leaving the nitrosoamine as a greenish-yellow oil.From a portion (26.5 grams) of the oily frac-tion boiling between 200° and 250° referred t o above 22 grams of phenyl-72-butylnitrosoamine were obtained. This is insoluble in cold water very sparingly so in hot water soluble in strong acids, and in most organic solvents. A fresh solution in acid is precipi-tated by so'dium hydroxide solution. The nitrosoamine is volatile in steam collecting in the distillate as a pale yellow oil heavier than water (compare Kahn Zoc. cit. p. 3367). Both 12-butylaniline and phenyl-n-bntylnitrosoamine can be readily nitrated yielding in each case yellow crystalline nitro-com-pounds which are scluble in alcohol or acetone and insoluble in water but can be recrystallised from concentrated nitric acid.They were not further investigated. Phen yl-n-hut ylh ydraoine . Phenyl-n-butylnitrosoamine (20 grams) dissolved in glacial acetic acid (50 grams) was slowly added t o zinc dust (100 grams) sus-pended in 200 C.C. of 90 per cent. alcohol and the mixture was constantly stirred and kept a t 10--20°. When all the nitrosoamin DERIVATIVES OF N-BUTYLANILINE. 1029 had been added the mixture was heated to boiling and quickly filtered to prevent the deposition of crystals. The zinc dust was washed repeatedly with small quantities of warm absolute alcohol, the washings being added to the filtrate. This nearly colourless filtrate was rendered slightly acid by the addition of concentrated hydrochloric acid and then evaporated to a small bulk.During t'he evaporation the solution gradually deepened in colour until finally it became dark red. The concentrated solution of the hydro-chloride was next treated with excess of concexitrated sodium hydr-oxide solution until the precipitate first formed was completely re-dissolved. The crude base which separated as a dark red oir was extracted with ether the &hereal layer dried over anhydrous potassium carbonate and the solvent evaporated. The residual oil consisted chiefly of plienyl-wbutylhydrazine together with some ~~butylaniline. The yield of crude oil was usually 75-83 per cent. of the weight of phenyl-jt -butylnitrosoaniine used. I n order to separate the 92-butylaniline from the phenyl-rt-butylhydrazine the crude oil was dissolved in dry benzene and dry hydrogen chloride passed through the solution until there was no more absorption.The benzene solution a t first changed to a deep red but later i t became paler in colour with the formation of a turbidity. The' benzene solution was filtered and evaporated to a small bulk, when the hydrazine was precipitated as a pale yellow crystalline mass on the addition of dry ether. By washing the precipitate with a small amouiit of benzene the liydrazine hydrochloride was dis-solved leaving behind the ?z-butylaniline hydrochloride. The phenyl-n-butylhydrazinet hydrochloride was recovered from the benzene solution and twice more subjected to this treatment when i t was obtained pure. From chloroform the hydrochloride sepa-rated in white needle-shaped crystals which are very readily soluble in water benzene chloroform methyl or ethyl alcohols and very sparingly so in ether or light petroleum (b.p. 60-80°). It reduces Fehling's solution on warming : 0.1030 gave 12-65 C.C. N a t 2 1 . 5 O and 747.3 mrn.: N=14*01. 0.1244 , 0*0900 AgC1. C1=17*90. C,,H,,N,,HC'l requires N= 13.96; C1= 17.67 per cent. Treatment with sodium hydroxide solution and extraction with ether gave the base as an almost colourless oil. It boils a t 247-250°/ 762.7 mm. decomposing slightly with the evolution of * In the nitrogen estimations recorded in this paper the gas was measured over 40 per cent. potassium hydroxide solution. The pressures recorded have been corrected for vaponr pressure of the potassinm liydroxide solution 1030 REILLY AND HICKINBOTTOM : ammonia.Under diminished pressure the base. can be distilled unchanged. Diphen yldi-n- 6 u t yl t e trazo ?I e . The crude phenyl-n-butylhydrazine was dissolved in ether and yellow mercuric oxide gradually added following Fischer's method f o r the preparation of the tetrazone from phenylmethylhydrazine (Annalen 1878 190 108). The red ethereal filtrate obtained on separation from the mercuric olxide and mercury was evaporated under diminished pressure and on addition of aqueous alcohol the tetrazone was obtained in slightly yellow flattened needles. These crystals were dissolved in a small amount of aqueous alcohol (60 per cent.) and placed in a vacuum desiccator over calcium chloride until tho tetrazone separated in white shining plates melting at 72-73O.After melting and cooling the melting point was again determined and found to be 73O. On heating above its melting point however, the compound gradually darkened until at 110-120° there was an evolution of nitrogen the liquid became dark brown and did not solidify again on cooling: 0.0906 gave 13-22 C.C. N at 14'7O and 758-5 mm. N=17-28. C,,H,,N requires N = 17-28 per cent. An aqueous-alcoholic solution of diphenyldi-~~-butyltetrazone rapidly decomposed the solution changing first to a mauve colour, then gradually t o violet and finally to blue and indigo. The violet or blue solution was changed t o an indigo colour by means of acids, and t o a reddish-mauve colour having a blue fluorescence by alkalis, these changes being reversible.Zinc dust and acetic acid destroyed the blue colour. Concentrated nitric acid changed the colour to yellow whilst aqueous iodine solution produced a dirty green coloration. Lactic acid gave the indigo colour which by the action or" potassium iodide changed to olive green. Dilute potassium per-manganate was reduced. The addition of bromine in carbon tetra-chloride solution changed the indigo colour t o a brownish-yellow. pNitroso-n-bu t ylaniline. Phenyl-n-butylnitrosoamine was dissolved in about ten times its volume of dry ether and four times its volume of alcoholic hydrogen chloride were added. I n a few minutes the green solution became red and after some time small brownish-red crystals of p-nitroso-n-butylaniline hydrochloride were deposited which were collected, washed with alcohol then ether and dried.It was found that pnitroso-n-butylaniline hydrochloride was less readily soluble in n-butyl alcohol than in ethyl alcohol. A butyl-alcoholic solution of dry hydrogen chloride was therefore use DERIVATIVES O F N-BUTYLANILINE. 1031 instead of the ethyl-alcotholic solution. The nitrosoamine was dis-solved in twice its volume of dry ether and two volumes of a solu-tion of dry hydrogen chloride in n-butyl alcohol were added. After two hours a copious yellow precipitate of the hydrochloride had formed the deposition of which was accelerated by stirring. It was collected washed with alcohol and finally with ether. To a solution of the hydrochloride in water an excess of ammonia was added when the base was precipitated as a green turbid oil which was extracted with ether.The ethereal extract of the nitroso-derivative was washed once with water and the ether eva-porated leaving the base as a green dark liquid which solidified on cooling t o a blue shimmering mass. It was purified by dis-solving in alcohol and adding water until a turbidity was produced. After somet time the base crystallised in long flattened needles melting at 58-59O: 0.1173 gave 16.32 C.C. N at 22'0° and 742.7 mm. N=15*73. C,,H,,ON requires N = 15.76 per cent. By slow evaporation of the ethereal solution the compound crystallised in large steel-blue prisms. It is only sparingly soluble ill water or light petroleum but dissolves readily in ether benzene, or alcohol.Concentrated solutions are green whilst dilute solu-ticns are yellow. The solid although steel-blue when in crystalline form is green o r yellowish-peen when powdered or crushed. The hydrochloride crystallises from a mixture of alcohol and ether in yellow needles which are changed to red and finally to a very dark colour by traces of hydrogen chloride: 0.2386 gave 0.1588 AgCl. C1= 16.47. It is very readily soluble in alcohol water or acetone but insol-uble in ether o r light petroleum. By the action of dilute nitric acid on the dilute aqueous solution of the hydrochloride a yellow crystalline nitro-compound was pro-duced insoluble in water acid o r alkali but soluble in alcohol or ether. On crystallisation from hot aqueous alcohol it was obtained in long yellow needles but was not further examined.C,,E€,,ON,,HCl requires C1= 16.52 per cent. Decomposition of pNitroso-n- b ut ylaniline with A lkali. 2'5 Grams of p-nitroso-n-butylaniline were added t o 40 C.C. of a 10 per cent. solution of sodium hydroxide and the mixture was distilled in a current of steam f o r twenty minutes the distillate being collected in an excess of dilute hydrochloric acid. .The red-dish-brown residue was neutralised with dilute sulphuric acid until the colour became pale green when the solution was extracted wit 1032 REILLY AND HIC!KINBOTTORI : ether. On evaporation of the ethereal layer a pale buff-coloured residue was left which dissolved in alcohol acetone or ether to a green solution. By slow evaporation of the ether the compound was obtained in almost colourless needles melting and decomposing a t 120-123O.It had the properties of pnitrosophenol and gave a red sodium salt crystallising from water o r from alcohol in red needles extremely readily soluble in water and sparingly so in ether or acetone. (Found Na=15*44. Calc. Na=15*85 per cent.) The hydrochloric acid solution in which the distillate had been collected was evaporated to dryness leaving an almost white residue which was identified as )L-hutylamine hydrochloride by the analysis of the platinichloride. Calc. Pt = 35.10 per cent.) The production of the primary aliphatic amine and pnitrosophenol from the nitrosoarnine proves that the nitroso-group by the actiou of alcoholic hydrogen chloride had migrated to the para-position, behaving in a manner similar to that observed when the lower alkyl derivatives of aniline such as phenylmethylnitrosoamine are simi-larly treated.(Found Pt = 34.87, p2\ritroso-n-bzstylunili~ieiiitrosoanLili e . Two grams of p-nitroso-76-butylaniline hydrochloride were dis-solved in a small amount of dilute hydrochloric acid the solutioii was cooled in a fr,eezing mixture and a concentrated solution of sodium nitrite (a slight excess of 1 mol.) was added slowly. A greenish-yellow flocculent precipitate separated which was col-lected after an hour. It was purified by dissolving in alcohol and adding water until a turbidity was produced and then leaving tlie mixture until crystallisation had taken place. The compound s e p -rated in small green plates melting a t 39.5O: 0.0855 gave 14.85 C.C.N a t 16'8O and 754.0 mm. p-2\'itroso-n-but?/lan~Zi?~en itrosoanzine is freely soluble in most organic solvents but almost insoluble in water. Dilute solutions become bright yellow by the action of alkalis whilst acids almost discharge the colour these changes being reversible. It was found that the colour of an alkaline solution could be discharged by the addition of one drop of / 20-sulpliuric acid. The compound responded t o Liebermann's test for nitroso-compounds. N=20.33. C,,H,,O,N requires N = 20.29 per cent. 11- ~ V I c 11 yle I I P -11- 7) 11 tyMio n2 iii e . Zinc dust (15 grams) was added gradually to a solution of 11-nitroso-n-butylaniline hydrochloride (10 grams) in water when a fairly vigorous reaction ensued attended by evolution of heat s DERIVATIVES OF N-BUTYLANILINE .1033 that i t was necessary to cool the mixture. After the reaction had moderated concentrated hydrochloric acid (45 c.c.) was gradually added and the mixture was heated for a short time on the water-bath until almost colourless. It was filtered hot from the excess of zinc dust which was washed repeatedly with warm dilute hydro-cliloric acid and finally with alcohol. The acid filtrate was then evaporated to about half i h bulk rendered alkaline with sodium hydroxide solution and the base which separated out as a dark-coloureld oil was extracted with ether. p-Yheihyleti e-n-b ittyldicimitre was obtained in a pure condition by the addition of an excess of dilute sodium hydroxide solution to a concentrated aqueous solution of the liydrochloride cooled in ice.The base separated as a white, ciystalline solid which was collected and washed with water. On recrystallisation from light petroleum it was obtained in white plates melting a t 31*5O having a pearly lustre. The colour slowly changed t o red on exposure to a i r : 0.0631 gave 9-45 C.C. N a t 1 8 . 5 O and '744.5 nini. An alternative method of obtaining the free base in a pure con-dition was also employed. The dark-coloured base was distilled instead of being converted into the hydrochloride. Under a pres-sure of 768 mm. it distilled over mainly a t 302*5-303*5O and on cooling solidified t.0 a white crystalline mass. It is readily soluble in most organic solvents but moderately so in cold light petroleum, and insoluble in water.p-PA enyl e tl e-n- b tctgldinnt i r i e dihydrochloride crystallised from l i d absolute alcohol in small glistening plates which did not melt a t 2ooo : N=l7*19. C,,H,,N requires N = 17.07 per cent. 0.0750 gave 7.80 C.C. N a t 20° and 746.3 mm. 0'1324 ) 0'1610 AgC1. C1=30.08. C,,H,GN,,2HCl requires N = 11.82 ; C1= 29-90 per cent. It is insoluble in ether sparingly soluble in cold absolute alcohol, more readily so in hot alcohol and very readily soluble in water. With a small amount of ferric chloride solution a neutral solution oE the hydrochloride gave a dirty green coloration which changed slowly through a succession of colours t o a dark red. The greeii colour was rejtored 011 adding inore lerric chloride.With potassiuni ferrocyanid e the hytlrochloride solution became olive-green chang-ii;g to blue on the addition of alkali. Oxidation by boiling with ferric chloride or potassiuni dicliromate and dilute sulpliuric acid produced an odour resenibliiig that of p-benzoquiaone. A solution of bromine in aqueous potassium bromide gave a yellow precipi-tate which gradually darkened on keeping. N = 11.90 1034 DERIVATIVES OF N-BUTYLANILINE. D i m o tisatio tz of p-Phenylene-n-b utyldiamin e Dihydrochloride . To an aqueons solution of the hydrochloride (1 mol.) rendered acid by the addition of hydrochloric acid (3 mols.) and cooled in a freezing mixture an aqueous solution of sodium nitrite was added until there was a slight excess of nitrous acid present.On first adding the sodium nitrite the hydrochloride solution became green and then rapidly turned to a brown tint. pAminodiphenylamine behaves in a somewhat similar manner (Jacobson loc. cit.). On adding this diazotised solution to an aqueous solution of platinic chloride a light yellow precipitate of the diazonium platinichloride was obtained which was collected and washed well with water and finally with alcohol and ether: 0.1888 gave 17.50 C.C. N a t 12O and 758.7 mm. 0.1509 , 0'0381 Pt. Pt=25*25. N=11*08. (C,oH,,N,Cl),PtC14 requires N = 11-05 ; Pt = 25.66 per cent. This salt was almost insoluble in water but spasingly so in alcohol. It commenced to darken a t 115-120° and decomposed a t 147-150° with a brisk evolution of nitrogen. When heated suddenly in a Bunsen flame it decomposed explosively. On the addition of an aqueous solution of the diazonium chloride, freed from nitrous acid by means of carbamide t o an alkaline solu-tion of &naphthol an azo-compound separated as a red crystalline powder which was collected after a few hours. I n the dry condition it is almost black and has a metallic lustre. It is insolub'le in water, but soluble in most organic solvents and dissolves in concentrated sulphuric acid giving a deep red colour. An acetylacetone deriv-ative was obtained 2s an orange precipitate on adding a solution of the diazotised pdiamine free from nitrous acid to art- alcoholic solution of acetylacetone. On the addition of sodium acetate there was a yellow turbidity from which crystals soon separated. The compound crysitallised from aqueous alcohol in yellow needles but, was not further examined. [Received November lst 1917.