174 HEWITT AND POPE: XIL-Derivcctwes of B?.omotolyllzyd?.oczi~ae? C,H,Br(CH,)(N,H,) [I : 3 : 61. By J. T. HEWITT, M.A., D.Sc., Ph.D., and F. G. POPE. SEVERAL years ago, one of the authors described orthochlorophenyl- hydrazine and several of its derivatives (Trans., 1891,59, 209 ; 1893, 63, 868). It was hoped that, under certain conditions, some of the * Wishing to test the working of the process in other hands, I asked one of our students, Mr. H. Jackson, of Downing College, to determine the sodium in a sample of pure sodium chloride. Proceeding according to the instructions given above, and using tho permanganate solution C, he obtained the following result : 0,2765 gram substance required 60.2 O.C. of permanganate. Na found = 39'29 per cent., Calculated 39'31 per cent,DERIVATIVES OF BROMOTOLYLHYDRAZINE.17 5 derivatives of this hydrazine might lose hydrogen from the side chain and halogen from the nucleus, forming closed ring compounds, but no results of any value in this direction were obtained, and the problem remained as to whether bromine compounds might not be more suitable for such syntheses. Orthobromaniline, however, is comparatively diffi- cult to obtain pure, whereas orthobromoparatoluidine can be prepared in any quantity by Wroblewsky's method (Annulen, 1873,168,153). The paratoluidine is first converted into acetoparatoluidide, the finely- powdered crude product (105 grams) is mixed with a large excess of cold water (1 litre), and the calculated amount of bromine (1 16 grams) run slowly into the mixture with continual stirring; the mixture is now raised to boiling, allowed t o cool, and the supernatant liquor run off the cake of orthobromacetoparatoluidide.The hydrolysis is readily effected by boiling the product with five times its weight of hydrochloric acid (2 vols. HUl: 1 water); on cooling, the hydrochloride of ortho- bromoparatoluidine separates out almost completely, and may be recrystallised from hot dilute hydrochloric acid. This hydrochloride is converted into the corresponding hydrazine hydrochloride by the methods proposed by Victor Meyer and Lecco (Bey., 1883, 16, 2976) and by Bamberger (Bey., 1896, 29, 1834); but as the former method gives better yields, we have used it exclusively. It is preferable to work with small quantities at a time. The finely powdered orthobromoparatoluidine hydrochloride (22 -25 grams), mixed with 10 times its weight of fuming hydrochloric acid, and cooled by ice and salt, is diazotised by the gradual addition of sodium nitrite (7 grams) dissolved in water (30 c.c.); after being left for 1 hour in the freezing mixture, it is poured, with continual stirring, into a solution of stannous chloride (37.8 grams) in its own weight of fuming hydrochloric acid kept well below 0".During conversion of the diazonium into hydrazine salt, it is necessary t o keep the temperature low,and i t is advisable to pour the diazo-solution into the stannous chlor- ide, otherwise the heat developed is liable t o decompose the diazonium salt, with production of tarry products. The double tin salt of the hydr- azine obtained is collected, and after drying on porous tiles, is dissolved in boiling water and freed from tin by bydrogen sulphide ; on concen- trating the clear solution, the hydrazine hydrochloride is deposited in colourless needles.An aqueous soliltion of this salt shows the characteristic reduction of Fehling's solution. Analysis.-C7H6Br*NH*NH2,HC1 requiresN = 11 *79 per cent. Found N = 11.51. The purified salt melts at 190" with slight evolution of gas. The free hydrazine can readily be obtained by precipitating ft solution of176 HEWITT AND POPE: the hydrochloride with ammonia ; after recrystallisation from ether, it is obtained in beautiful, colourless, silky needles melting a t 91". AnaIysis.-C7H,Br*NH*NH2 requires N = 13.93 per cent, Found N = 13 96 per cent.Salts of the hydrazine were prepared by dissolving it in ether, and adding ethereal solutions of the corresponding acids. The mitrate separates from the ethereal solution in radiating masses, SO that the liquid is soon filled with a paste of crystals, white and pearly in appearance ; after being dried on a porous tile, they melt at 154' with slight decomposition. Analysis.-C7H,Br*NH*NH2,HN0, requires N = 15.91 per cent. Found N = 15.29 per cent. Xu1phate.-This was prepared in a similar manner, but an excess of acid had to be avoided or the sulphate and excess of acid separated as a heavy oily layer. By recrystallisation from boiling water, the suIphate was obtained in long, colourless needles easily soluble in bot, but only sparingly in cold, water, and melting a t 201".Analysi~.-(C~H,~r*~,H~)~,H~~~, requires so, = 19-20 per cent. Found SO,= 19.22 per cent. The oxalate was immediately precipitated as a colourless, crystalline paste on mixing ethereal solutions of the hydrazine and anhydrous oxalic acid ; the product was collected, dried on a tile, and recrystallised from boiling water, in which it dissolves fairly when hot, but only very slightly when cold. It separates in small, colourless prisms soluble in hot alcohol, and melting a t about 150°, the exact tempera- ture depending on the rate of heating; decomposition takes place apparently, the molten mass frothing, although it still remains colourless, so that probably the reaction consists in the formation of a hydrazide. Analysis.-(C7H,Br*N,H,),,C,0,H2 requires N = 11 *39 per cent.Found N = 11.64 per cent. Besides the above salts, we have characterised the hydrazine by converting it into a number of derivatives. AcetylbromotolylJ~yds.azine was prepared by boiling the hydrazine with excess of glacial acetic acid for some hours in a reflux apparatus; the product was then poured into water, collected, and recrystallised twice from dilute acetic acid. It forms small, thick prisms melting a,t 124". Analysis.--C7H6Br*NH*NH*CO*CH, requires N = 11.53 per cent, Found N = 11.77 per cenl;. The composition was confirmed by a nitrogen estimation.DERIVATIVES OF RROMOTOLYLEYDR~AZINE. 177 This acetyl derivative dissolves slightly in hot, but is practically insoluble in cold, water ; i t is also insoluble in light petroleum, and in benzene and its homologues.It is taken up sparingly by ether, dissolves in alcohol and glacial acetic acid, and is dissolved with great readiness by chloroform. Rromotolylsemicccr6axide was immediately precipitated on mixing aqueous solutions of the hydrazine hydrochloride, and potassium cyanate in molecular proportion. It was collected, washed with cold water, and recrystallised from a large quantity of boiling water, in which it is only sparingly soluble ; it is nearly insoluble in cold water. Bnalysis..-C7H,Br*NH*NH*C0.NH, requires N = 17.21 per cent. Found N = 17.14 per cent. This semicarbazide is insoluble in light petroleum and benzene ; dissolves somewhat in chloroform, and is readily soluble in ether, acetone, and glacial acetic acid. Bromotolylallyltl~iosemica~baxide was obtained by mixing ethereal solutions of allylthiocarbimide and the hydrazine in molecular propor- tion ; on evaporating the ether, the thiosemicarbazide was left as an oil, which, on long continued stirring, solidified to a hard mass.On recrystallisation from alcohol, it was obtained in colourless prisms, the faces of which are often striated, the prisms themselves being frequently united in clusters. The ends of the prisms were usually badly developed. A sulphur estimation gave S = 11.55 per cent. C?H,Br*NH*NH*CS*NH*C::H; requires S = 11.23 per cent. It melts a t 163'. This semicarbazide melted at 136*5", and showed no signs of the isomerism observed by Marckwald in compounds of a similar type. It dissolves in alcohol, ether, ethylic acetate, acetone, benzene, carbon bisulphide, and glacial acetic acid, but is insoluble in light petroleum.On adding copper sulphate solution to the ethereal solution, the latter becomes yellow, and turns a very dark olive brown on adding ammonia. BromotolyZpiLenylthiosemica~~~~i~~ was obtained in like manner, using ethereal solutions of the hydrazine and phenylthiocarbimide. On evaporating the ether, an oil was left which solidified on stirring it up with a small quantity of light petroleum. Dried on a porous tile, it melted almost completely about 122-1 25O, but after crystallisation from hot alcohol and drying at looo, the melting point mas found to be 142". The substance, when somewhat rapidly deposited from alcohol, forms t u f t s of prisms, whilst by slower evaporation the prisms are obtained singly and are all terminated with well-defined oblique faces.Analysis.-C7H,Br*NH*NH*CS*NH*C,H, requires S = 9.52 ; Br = 23.81 per cent. Found S = 9.55 ; Br = 22.63 per cent, VOL. LXXIII. N178 HEWITT AND POPE: As t o whether the above-mentioned behaviour of the substance on heating is to be ascribed to isomerism in the sense indicated by Mai-ck- mald (Be?.., 1892, 25, 3098) in the case of diphenylthiosemicarbazide, me cannot say ; it is, however, strange that, on mixing solutions of pure hydrazine and allyl- or phenyl-thiocarbimide and evaporating, the respective thiosemicarbazides should be obtained as viscous liquids which do not readily solidify. The substance is easily soluble in cold chloroform and acetone, and in warm alcohol, and fairly so in ether ; but benzene, toluene, xylene or amylic alcohol take it up easily, It does not dissolve very easily in concentrated sulphuric acid, and in ammonia, even if warm and concen- trated, but very sparingly, if at all.Warm' dilute soda solution takes it up easily, but it is reprecipitated by hydrochloric acid. The thio- semicarbazide is turned superficially red by the vapour of fuming nitric acid ; in actual contact with the fuming acid, it catches fire. ~~c~~~raZdehydebrol?totolyll~ydraxone.-Furfuraldehyde (1 gram) in a small bottle, was covered with water, and a solution of the hydrazine hydrochloride (2.5 grams) added; on adding a solution of sodium acetate, the hydrazone was precipitated as an oil which obstinately refused to solidify, but after a month it became nearly solid, and on washing with a little alcohol and stirring, complete solidification was induced.When slowly crystallised from warm alcohol, it was deposited in well-defined, brown needles which melted a t 87'. Analysis.-C,H,0*CH:N*NH*C7H6Br requires N = 10.03 per cent. Found N = 9.77 per cent. Furf uraldehydebromotolylhydrazone dissolves easily in ether, ethylic acetate, chloroform, acetone, and glacial acetic acid, but is insoluble in light petroleum. BenxaldehydebromotolyZiLydraxone, prepared in a siinilar manner, sepa- rated a t first as a pale yellow oil, which, however, on vigorous shaking, was suddenly transformed to a nearly colourless, crystalline mass ; by recry stallisation from alcohol, it was obtained in well-defined, colourless, rhomboidal plates which melted a t 84'; the alcoholic solution frequently shows the phenomenon of supercooling.Benzaldehydetolylhydrazone dissolves in ether, chloroform, ethylic acetate, benezene, and glacial acetic acid, but is insoluble in light petroleum. Analysis.-C,H,*CH:Pr'*NH*C7H6Br requires N = 9.69 per cent. Found N = 10.11 per cent. ~~~ZicylaldehydebromotolyZ~ydrccxorte.--The free hydrazine liberated from 4 grams of the hydrochloride by 2 grams of sodium acetate was collected, washed, and dissolved in alcohol ; on adding the calculated quantity (2 grams) of salioylaldehyde, a brownish oil separated imme-DERIVATIVES OF RROMOTOT,YT,HYDRAZINE. 179 diately, and this, after the supernatant liquid had been removed, be- came solid on stirring vigorously with some light petroleum.The crystalline mass, after being washed with light petroleum and re- crystallised successively from ether and alcohol, was obtained in long, straw-coloured needIes which melted a t 109'. Analysis. -OH* C,H,* CH:N*NH* C7H,Br requires N = 9.18 per The salicylaldehydehydrazone dissolves in ether, acetone, chloroform, ethylic acetate, carbon bisulphide, benzene, and glacial acetic acid, but only sparingly in alcohol, and is insoluble in light petroleum. Pyvuvic acid 6~omotolyZhydvccxone is completely precipitated by mixing aqueous solutions of the hydrazine hydrochloride and pyruvic acid ; the pale yellow flocks thus formed, after being washed and re- crystallised from hot dilute alcohol, are obtained in bright yellow crystals which melt a t 175' to 5t clear yellow liquid, some gas being evolved.The substance is soluble in chloroform, ether, acetone and glacial acetic acid, but insoluble in benzene and light petroleum. Analysis.-C7H,Br*NH*N: C(CH,)*COOH requires C = 44.28 ; H = 4.06 per cent. EthyZic pyuvate bromotoZyZiLyd~(~xo?ze was prepared by boiling the acid for 2 hours with an equal weight of concentrated sulphuric acid and 10 times its weight of alcohoi, using a reffux apparatus. The mixture was then poured into a dilute solution of sodium carbonate, allowed to stand overnight, and the substance collected, washed, and dissolved in alcohol ; on allowing the solution to evaporate slowly, the compound was deposited as tufts of slightly yellowish needles. cent.Found N = 9.08 per cent. Found C = 44-30 ; H =: 4.09 per cent. Analysis.-C7H,~3r*NH.N: C(CH,)*COOC,H, requires N = 9.36 per It softens about 7.5" and melts a t 84-85'. It is easily soluble in the usual solvents. Various salts of this acid were prepared, in the hope of eliminating the metal in union with bromine, on heating, and so possibly obtaining closed ring derivatives. As the experiments in this direction have not as yet yielded very satisfactory results, we have decided to publish the remainder of our work now, and leave this portion for a future com- munication. Thepotnssiunt scdt was prepared by mixing the acid with the calcu- lated quantity of pure anhydrous potassium Carbonate, adding water, and warming until the evolution of carbon dioxide had ceased.Enough water was then added to dissolve all the salt on boiling, and the solution, filtered hot, was allowed to cool; the salt then separated in cent. Found N = 9.83 per cent. N 2180 DERIVATIVES OF RROMOTOLYLHYDRAZINE, fern-like aggregates, which were collected with the aid of the pump, washed with alcohol, and air-dried. Analysis.-C7H,Br*NH*N: C(CH,)*COOK + 3H20 requires H20 = 14.60 ; K = 10.74 per cent. Found H,O = 14.56 ; K = 10.33 per cent, The ammonium salt was obtained by dissolving the acid in hot dilute ammonia; the crystals deposited on cooling are, like those of the potassium salt, not very soluble in cold water. Analysis.-C,H,Br*NH*N: C(CH,)*COONH, requires N = 14-58 per cent. The aqueous solution of this salt gives precipitates with solutions of salts of the heavy metals.The precipitate with silver nitrate be- comes violet coloured on drying, and decomposes readily on heating. The analysis of the dried salt showed that considerable decomposition had taken place, it contained 34-56 per cent. of silver, whilst the salt C,,H,,BrN202Ag should contain 28.57 per cent. The lead salt is a pale yellow, amorphous powder ; dried a t 105O, i t gave a percentage of lead agreeing with the theoretical numbers. Analysis.-[C7H,Br*NH*N: C(CH,)COO],Pb requires Pb = 27.71 per cent. Action of Heat on these Sdts.-The anhydrous potassium salt, when heated gradually, remains unchanged below 2 15O, but at this temperature, a brisk reaction takes place, the salt melts, the mass darkens and froths up, and small quantities of liquid distil up the sides of the tube. On cooling and extracting the melt with hot water, the aqueous solu- tion was found to contain potassium bromide; the insoluble portion yields extracts both with dilute hydrochloric acid and dilute soda. It is thus seen that both a basic and acidic (or a t least phenolic) sub- stance are formed during the change ; their nature has, however, not yet been determined. The lead salt decomposes a t about 160' or 170". Much lead bromide is formed, and again both acid and basic products can be detected, A. similar decomposition takes place, and apparently more smoothly, by heating the lead salt with an indifferent hydrocarbon solvent for some hours in sealed tubes at 180'. We hope to shortly return to this subject, and lay the results obtained before the Society. Found N = 14.40 per cent. Found Pb = 28.05 per cent. EAST LONDON TECHNICAL COLLEGE,