GRTESS ON A NEW CLAW OF 298 XLVII.-On a New Class of Organic Compounds in which Hydrogen is replaced by Nitrogen. By PETER GRIESS.. THEinteresting substances described in the first part of this paper (p. 268) obtained by the action of nitrous acid upon some of the amido-acids of the phenyl group induced me also to study the action of nitrous acid upon similarly constituted bodies from other groups. 1 have thus obtained a number of remarkable products of which for the present I will describe only those which may be referred to amido-acids belonging to the family of aromatic acids. Here also the reaction takes place in a similar manner to that previously described yet a coiisiderable difference is observed in the fact that the atoms of nitrous acid and amido-acid which act upon each other are not equal in number but that one atom af nitrous acid acts upon two atoms of the amido-acid.Diazodinitrophenol is formed according to the equation- C6H,N,05 + NHO = C,H,N,O + 2H20. Picramic acid. Diazodinitrophenol. On the other hand the action of nitrous acid upon amido- benzoic acid for illstance is expressed by the equation-2C,H7N0 + NHO = C,,H,,N,O +-2H20. Amidobeneoic New compound. acid. ORGANIC COMPOUNIX3 ETC. 299 The compounds which arise according to the last equation possess all the characteristic properties of the bodies described in the first paper. They exhibit moreover many peculiarities which are partly founded on their complicated composition and are par- ticularly manifested by a larger number of products of decomposi- tion.I refrain from treating minutely of these relations at present and content myself with giving first a special description of the preparation and properties of one of these substances. DIAZO-AMIDOBENZOIC Ac~D. This substance is prepared hy passing a current of nitrous acid into a cold saturated alcoholic solution of pure amidobenzoic acid C,II,(H,N)O,. After the gas has been passing for a few moments the wine -red colour disappears and immediately or after a short time the new body separates in the form of an orange-yellow crystalline powder. The heat generated must be moderated by cooling with water. When the quantity of the precipitate no longer increases the operation is discontinued and the new sub-stance collected on a filter in order to separate it from the mother-liquor.Frequent washing with warm alcohol renders it perfectly pure. An aqueous solution of amidobenzoic acid when submitted to the action of nitrous acid also yields the new body. This mode of preparation however is scarcely to be recommended as the resulting product is never so pure or so beautiful as that obtained by the first method. The following process on the other hand is very advantageoils especially when working with small quantities. It is based on the observation that the ethers of nitrous acid exert the same action upon amidobenzoic acid as the free nitrous acid itself. On mixing an alcoholic solution of nitrous ether (which for this purpose may be prepared simply by saturating cold alcohol with nitrous acid) with an alcoholic solution of amidobenzoic acid scarcely any alteration takes place in the cold; but on gently heating tlle mix- ture up to about 30" its colour at once changes from red to yellow whilgt the new body is precipitated in abundance generally in the form of microscopic needles which are rendered perfectly pure by washing with alcohol.Pure nitrite of ethyl as well as nitrite of amyl produce exactly the same results. Analysis of the acid led to the formula The fidlowing equation explains the formation of this substance for which I have proposed the name of Diazo-amidobenzoic Acid. 2C7H7N0 + NHO = C,,H,,N,O + 2H,O. drnidobenzoic New acid. acid. In fact the operation may be conducted in such a manner that the quantity obtained corresponds almost exactly with that required by theory.As a rule however other products arise in variable proportions the formation of which is chiefly due to an excess of nitrous acid. In a subsequent part of this paper I shall again refer to this circumstance. Diazo-amidobenzoic acid is obtained in small crystals of a beautiful orange-yellow colour. They appear as small prisms when seen under the microscope. It is inodorous and tasteless almost insoluble in water alcohol ether ksulphide of carbon and chloroform and consequently cannot well be recrystallised from these solvents. Mineral acids dissolve it readily especially on the application of heat but it cannot be separated from them again without decomposition.When dissolved in a solution of potash or ammonia and then neutralised with an acid the new substance is precipitated all unaltered in the form of a yellow gelatinous mass. It can be dried at 100" without decomposition. At 180" it deflagrates in consequence of a rapid evolution of gas. Although diazo-amidobenzoic acid is a somewhat weal acid it nevertheless completely saturates the strongest alkalis and expels carbouic acid from their carbonates. SALTSOP DIAZO-AMIDOBENZOIC ACID.-Although diazo-ami-dobenzoic acid always combines with two atoms of metal yet it cannot be viewed as a bibasic acid if by that term is understood an acid containing a diatomic radical and capable of forming two series of salts-acid and neutral-as it fulfils neither of these conditions.It assumes more the character of a compound acid. Diazo-amidobenzoate of Potnssium C14H9K2N304. In order to ORGANTC CO%IPOUNDS ETC. obtain this salt a quantity of the acid is introduced into a large excess of a concentrated aqueous solution of carbonate of potas-sium which has been heated up to 80°. On cooling a quantity of extraordivarily small needle-shaped crystals separate they are of a yellowish-white colour and when floating in the mother-liquor give rise to a most vivid fluorescence. Diazo-ainidobenzoate of Ammonium Cl,HB(NH4)%N30,, crystal-lises in microscopic needles which when in aqueous solution are readily decomposed by heat. Diazo-amidobenzoate of Sodium C,,HgNa,N30, resembles the potassium-salt in all respects.Diazo-arnidobenzoate of Barium C14HgBa2N~04, is obtained in the form of a yellowish-white crystalline precipitate on treating the potassium-salt with a sdution' of chloride of barium. In order to purify it for analysis it is well washed with water and dried over sulphuric acid This salt is nearly insoluble in water quite insoluble in alcohol and in ether. When 5eated on platinum-foil it deflagrates. Diazo-amidobenxoate of Magnesium crystallises in yellow needles easily soluble in water. Diazo-amidohenzoateof Xiher C,,HgAg2N,04,falls as a greenish-yellow mass on treating a neutral solution of the acid in ammonia with nitrate of silver. It is purified from the mother-liquor by repeated washing with water.When dried it appears its a yellow powder equally insoluble in water alcohol and ether. It remains unaltered at 100". At a higher temperature it deflagrates with violence thus rendering it impossible to determine the silver by heating. The analysis is however easily performed by dissolving the salt in dilute nitric acid and precipitating the silver with hydrochloric acid. The calcium-salt is a yellowish-white precipitate resembling the barium salt. A solution of the potassium salt gives a yellowish-green pre- cipitate with chloride of mercury and a yellow precipitate with chloride of iron. Diazo-amidobenzoate of copper when dry appears as a green amorphous powder. The zinc salt is yellow amorphous insoluble in water.Diazo-arnidobenzoate of EthyZ C,,Hg (C,H,),N,O,. This com-pound is prepared by passing a stream of nitrous acid through an alcoholic solution of amidobenaoic ether C7H4(H,N) (C,H,)O,. T'OL. XBI I I. x GRTESSI ON A NEW CLASS OF Yellorv crystals soon appear in the solutiori. They rapidly iu- crease and soon cause the whole liquid to solidify. The crystals are collected on a filter and separated from the mother-liquor by washing with cold alcohol. One recry stallisation from boiling alcohol yields this body in magnificent hair-like needles of an almost golden-yellow colour. They are insoluble in water but dissolve readily in alcohol and in ether. They fuse at 144" (uncorr.) but do not resolidify on cooling uritil the lapse of several days.At a higher temperature they are decomposed with evolution of nitrogen. The deportment of the ether towards dilute acids appears to be that of a weak base dissolving in them although with difficulty and being reprecipitated on addition of ammonia. It would however he difficult to obtain definite compounds as it is scarcely possible to prevent the acids from causing a further decomposition. The formation of the ether takes place according to the following equation :-2C,H4(H2N)(C2H5)0 + NHO = C,,H,(C,H,),N,~ + 2H,O. Amidobenzoic ether. New ether. Diazo-amidobenzoate of MethyZ C H (CH,)N,O, is prepared by acting upon an ethereal solution of amidobenzoate of methyl with nitrous acid. The new ether separates in small crystalline globules or in short lance-shaped yellow crystals.It melts at 160" (uncorr.) and on resolidifying exhibits the same peculiarity as the preceding compotind which it also resembles in all other respects. PRODUCTSDECOMPOSITION ACID. OF OF DIAZO-AMIDOBENZOIC Action of the Hatoid Acids upon Diazo-armmidobenzoic Acid.-On treating this acid with strong hydrochloric acid no reaction is observed at the ordinary temperature but on gentle heating an evolution of nitrogen takes place the original acid disappears whilst a crystalline body is produced. It is separated by filtration from the mother-liquor from which a second white crystalline substance is obtained on evaporation. The first body is purified by dissolving in a large quantity of boiling water and decolorising with animal charcoal.On cooling a copious crystallisation of delicate white needles is obtained iv hich arc rendered perfectly pure by a second crystallisation. They are easily soluble in O1:CfANIC CO3fPOUND8 ETC. alcohol and in ether with difficulty in cold more readily in hot water; they are so volatile that they cannot be dried in the water- bath without loss. This substance is a well-defined acid. An analysis gave numbers leading to the formula of chlorobenzoic acid C,H,C10,. Limpricht and Uslar were the first to point out that chlo- robenzoic acid produced by the decomposition of chlorinated chloride of benzoyl with water is not identical with the substance of the same composition obtained by distilling salicylic acid with pentachloride of phosphorus and treating the resulting distillate with water.The latter acid discovered by Chiozza was in a more recent research by Kolbe and Lautem ann,* distinguished as a peculiar acid and called by them chlorosalicylic acid. Both the crystalline form and the melting point (152" uncorr.) of the compound prepared according to my method decided me in declaring it to be identical with the chlorobenzoic acid of Limpricht and Uslar. I have mentioned another product of decomposition which is found dissolved in the hydrochloric mother-liquor from which the chlorobenzoic acid had been separated. This second body is obtained in a state of perfect purity by evaporating the hydro-cliloric acid dissolving the residue in alcohol precipitating with ether and several times recrystallising the precipitate.The sub- stance thus obtained corresponds perfectly in its crystalline form its sweetish-sour taste and its beautifully crystallised platinurn- salt with hydrochlorate of amidobenzoic acid. Its identity was further established by a chlorine determination. The following equation may serve to elucidate this transforma- tion :-CI4Hl1NBO4 + 2HC1= C,H,ClO + C7H5(H,N)O2.HCl+ N,. The quantities of the products of deccmposition obtained cor- respond with this assumption as shown by the following deter- mination of the quantity of the nitrogen evolved. The substance was introduced into a long-necked flask from which the air had been expelled bv a stream of carbonic acid and treated with a sufficient quantity of hydrochloric acid.The gases evolved during ebullition were coilducted into a graduated glass tube filled with * Ann. Ch. Pharm. cxv. 183. 22 GRIESS ON A NEW CLASS OF potassa solution. The gases remaining in the flask were driven into the graduated tube by a fresh current of carbonic acid. After absorption of the carbonic acid the residue was found to be pure nitrogen. 1:06 grm. of substance cried at 100' and decomposed with hydrochloric acid gave 75 C.C. nitrogen at Oo and 760 mm. bar. = 8.9 px. The equation given above requires 9.9 p.cs These facts lend a powerful slipport to the view that diazo-amido- benzoic? acid is a compolind acid of diazobenzoic acid and amido-benzoic acid yiz. :-By taking this formula the decomposition by hydrochloric acid is at once explained.In the first stage of the reaction the original compound is split up iuto its two constituents amidobenzoic acid and diazobenzoic acid and in the second the diazobenzoic acid which possesses but little stability exchanges its two atoms of nitrogen for hydrochloric acid thus forming chlorobenxoic acid. This view of the rational formula of diazo-amidobenzoic acid is still further confirmed by the following experiments :-On heating the dry substance to 180" or 190' in an apparatus similar to that above described a violent reaction suddenly ensues which if much substance has been employed assumes the character of a weak explosion. Torrents of nitrogen are evolved and are col- lected in the graduated tube.The neck of the flask containing the substance becomes filled with a sublimate of white crystals whilst a fused substance remains at the bottom. The gas collected in the graduated tube is pure nitrogen whilst the crystals by their sweetish taste and their deportment with nitrous acid with which they yield the original substance* are at once recognised as ami- dobenzoic acid. The fused substance remaining at the bottom of the flask pos-sesses the character of an acid ; it is insoluble in water but easily soluble in alcohol. I have not analpsed it; the mode of its formation however can leavc scarcely a doubt of its composition * The deportment of an alcoholic solution of amidobenzoic acid with nitrous acid offers a simple method for thc detection of the latter.Even traces of nitrous acid contained in an alcoholic or ethereal liquid may easily be reeogniscd by the formci- tion of diazo amidolJenzoic acid being C7H,0,. The reaction would coiisequently take place thus :-C,,H,,N,O = C7€17N0,+ C,H,O + N,. Diazo-amidoben-Amido-benzoic New acid. zoic acid. acid. The qnantity of nitrogen actually obtained corresponded with that required in the preceding equation. 0.447 grm. substance gave 33.9 C.C. nitrogen at 0" and 760 m.m. bar. = 9-53 p.c. ; theory 9.8 p.c. This experiment shows that the same quantity (viz. 3 of the total amount) of nitrogen which is expelled from diazo-amidobenzoic acid by hydrochloric acid is also set free by the action of heat alone.A totally different result is obtained on attempting to deter-mine the amount of nitrogen by ignition with soda-lime. Here actually only the one equivalent of nitrogen contained in the double acid in the form of amide is converted into ammonia the other two atoms of nitrogen escaping as such. 0.4785 grm. gave 0.3895 grm. platinum-salt corresponding to 4.6 p.c. of' nitrogen. Tlie quantity of nitrogen in the form of amide contained in diazo-amidobenzoic acid is 4.9 p.c. Diazo-amidobenzoic acid must therefore be added to those sub-stances which cannot be analysed with correct results by the method of Will and Vnrrentrapp. Action of Hydriodic acid upon Diazo-arnidobenzoic acid-On heating diazo-amidobenzoic acid with aqueous hydriodic acid the same phenomena are observed as those produced by the action of hydrochloric acid.Two new bodies are formed one of which separates as a reddish-coloured crystalline mass whilst the other is retained in solution by the acid mother-liquor. If t,he first be dissolved in very dilute alcohol and digested with a little animal charcoal the filtered solution c;n cooling deposits a copious crop of white or slightly-reddish crystals which are rendercd fit for analy- sis by a second crystalhatiol;. The new substance appears in the form of delicate platres ex-tremely soluble in alcohol and in ether but difficultly soluble in water. Adtlysis proved thein to be iodobenroic acid C;,H,IO,. The mother-liquor of this acid contains hydriodate of amido-lxnzoic acid mhicli whcn purified forms whitc riccdles of sw:.etisll-sour taste easily soluble in water difficultly soluble ilk alcohol iiisoluhle iii ether.BRIESS ON A NEW CLASS OF The formation of the two products just described is accom- plished in exactly the same manner as that of chlorobenzoic and amidobenzoic acid :-C14H,,N,0 + HI = C7H,I0 + C7H7N0,. It appears thus that the formation of chlorobenzoic and of iodo-benzoic acid is based upon a new and most peculiar mode of sub-stitution the pecnliarity of which consists in the replacement of two atoms of nitrogen by one atom of hydrochloric or hydriodic acid. Doubtless similar results will be obtained with other hydro- gen acids and will thus give rise to many new and interesting com pound s. Not only these acids however but also their ethers decompose the double acid with evolution of nitrogen.I have not had sufficient time at iny disposal to submit the pro-ducts thus obtained to a more minute examination. Action of Chlorine Bromine and lodine upon Diazo-arnidobenxoic Acid. Chlorine bromine and iodine individually act upon diazo-arnidobenzoic acid. The degree of energy with which this action takes place as well as the formation of distinct products is deter- mined not only by the nature of the element but also in an eminent degree by the form in which the element is employed whether in the anhydrous strte or in the presence of water or alcohol. The addition of anhydrous bromine to the double acid gives rise to an explosive decomposition; torrents of nitrogen and liydrobromic acid are evolved whilst the residue is changed to a brownish easily fusible resin.This resin is nearly insoluble in water easily soluble in alcohol and in alkaline liquids; acids reprecipitate it from the latter without alteration. It evidently consists of a mixture of brominated acids from which it is scarcely possible to isolate a definite compound by crystallisation. When the resin is submitted to dry distillation in a retort a brominated derivatiye of benzoic acid sublimes whilst the residue is charred with evolution of hydrobromic acid vapours. Finely divided diazo-amidobenzoic acid suspended in water and submitted to the action of bromine yields products differing in a ORGANIC COMPOUNDS ETC.marlied manner from those produced by the action of anhp-drous bromine. For although the resin above-mentioned is formed in considerable quantity yet chiefly crystallisable acids are produced the scpni*ationof cvliicli however is still attended with clifficul ty. If we bear in mind that in the action of bromine upon water we produce hyrlrobromic acid and oxygen and assuming the simplest case that both these in combination with an excess of bromine act only upon the first constituent of diazo-amidobeneoic acid viz. upon the atomic group C,H,N,O, it is obvious that at least the two following series of acids may be formed :-C,H,BrO C N,Br0 C,H,Br,T) C,€I,B,O,. If we further consider tliat the second constituent of diazo-arnidobenzoic acid is likewise acted upon by bromine the number of substances capable of being produced by this reaction is still further increased.I have endeavoured to obtain some of them by recrystallising the mixture from hot water and alcohol. Bromo-benzoic Acid C7H5Br02 crystallises in beautiful long plates of a pearly lustre difficultly soluble in hot water but readily dissolved by alcohol and ether. Trihromobenxoic acid C7H,Br,0, is obtained in small needle- shaped prismatic crystals which in their deportment with solvents differ but little from the preceding compound. They may be volatilized without decomposition. Chlorine in every respect resembles bromine in its action upon diazo-amidobenzoic acid. The double acid is decomposed with evolution of nitrogen and formation of chlorinated derivatives.The action of iodiiie upon diazo-amidobenzoic acid is less energetic than that of bromine ; dry iodine-vapour does not attack the acid at all. It is on the other hand easily decomposed when suspended in hot water and treated with iodine. The iodine- vapours soon change the original cornpound into a brown nearly insoluble crystalline body and into a second substance which is dissolved by the water ; a considerable evolution of nitrogen takes place at the mine time. The first substance is obtained in R state of purity by dissolving it in very dilute alcohol digeating with animal charcoal and once re-crystallising the product from GRTESS ON A NEW CLASS OF alcohol and ether. It is a well defined acid and appears gene- rally in long narrow nearly colourless plates which by the application of a gentle heat may be sublimed without decom- position.On rapidly heating them they are decomposed with evolution of iodine-vapour. A combustion made of the pure acid gave numbers leading to the formula of iodoxybenzoic acid C,H,IO,. The second product which remains dissolved in the water is obtained by evaporating the solution and recry stallising the residue from boiling water. It is hydriodate of amidobeiizoic acid. The following simple equation elucidates the formation of these two substances :-C14HllN304+ I + H20 = C,H,IO + C,H,N02.HT + N,. Action of Nitric Acid upon Diazo-amidobenzoic Acid.-Diazo-amidobenzoic acid is immediately destroyed by fuming nitric acid with evolution of light.In ordinary concentrated uitric acid it dissolves readily with a reddish colour; on heating however a violent reaction ensues the liquid rapidly frothing up whilst quail- tities of red fumes are evolved. On evaporating the excess of nitric acid on the water-bath a powerfully acid viscid residue is obtained which is frequently interspersed with crystals and is readily taken up by all solvents. It con8ists chiefly of a new cvstallisable acid which may be purified in the following manner. The residue is dissolved in water and the solution treated with an excess of baryta-water hy which a resinous matter is thrown down. After separating the precipitate the solution is freed from the excess of baryta by passing a stream of carbonic acid then filtered and the filtrate is evaporated on the water-bath uutil a crystal-line pellicle appears on the surface.On cooling a quantity of tlie harium-salt formed crystallises out in thick yellow needles. By again evaporating the mother-liquor the rcmaiiider of tlie salt is obtained. After the salt has been purified by several re-crystallisations it is dissolved in water and mixed with a quantity of sulphuric acid just sufficient to precipitate the whole of the baryta. The solu-tion when evaporated yields the new acid in rhombic prisms of a yellow colour which when re-crystallised from alcohol or ether are perfectly pure. An analysis of the substance dried at 100’ gave numbers corresponding to the formula C I13NsO~y ORG-4NIC COMPOUNDS ETC.309 I propose for it the name of trinitrooqthenzoic acid. It is a bibasic acid and its constitution may be expressed by the followiiig formula :-C:,I-I (NO,),a,. It crystallises in well defined rhornbic prisms and is extremely soluble in water as well as in alcohol and ether. The acid when dry is nearly white yet its solution possesses an intense yellow colour and like picric acid imparts that coloiir to animal membranes. It has an intensely bitter taste melts when warmed arid deflagrates at a higher temperature. Sulphide of ammonium reduces it with formation of a new body and separation of sulphur. It combines with bases forming well defined salts iiearly all of which are soluble in water whilst some are beautifully crystal- lised.I have only examined a few of them. T?*initrooccyhenzoate of Bari~m.-6,ffBa,(h’0,),03 is easily soluble in water ; a boiling saturated solution however deposits but few crystals on cooling its solubility in hot and in cold water differing but little. By spontaneous evaporation of the aqueous solution this salt is obtained in thick needle- shaped con-centric crystals of an intense yellow colour. They are all but insoluble in alcohol and ether and extremely explosive. They contain water of crystallisation part of which they lose on beirig dried over sulphuric acid. The ammonium-saltis prepared by saturating the acid with aqueous ammonia; it forms yellow prisms easily soluble in water but diffi- cultly soluble in alcohol ; they resemble picrate of ammonium in many respects.The silver-salt C,HAg,(NO,),O, appears in the form of yellow globular crystals easily soluble in water. Action of Nitrous Acid apon Diazo-umidobcnzoic Acid.-The products which are obtained on submitting the double acid to the decomposing influence of nitrous acid differ according to the presence either of alcohol or of water. Action of Nitrous Acid in the presence of Water.-The double acid when suspended in boiling water and submitted to a current of nitrous acid is completely decomposed with evolution of gas; the resulting red liquid on cooling deposits a reddish crystalline substance. Recrystallisat ion from boiling water with addition of a little animal charcoal yields it in hcautiful narrow plates of -.a ~ightyellow colour. ‘l’liis substance is witrocxybenzoic creid (I,T-I,(NO,)O, already dcscyibecl by G erl a lid. 310 GRIESS ON A KEW CLASS OF Action of Nitrous Acid in presence of AZcohoZ.-On suspending diazo-amidobenzoic acid in alcohol saturated with nitrous acid and passing a current of the same gas through the liquid whilst the whole is kept in ebullition exactly the same phenomena are observed. as those previously enumerated. The double acid is rapidly dissolved with formation of a deep brownish-red solution and simultaneous evolution of nitrogen. On evaporating the alcohol as soon as the double acid has completely disappeared a reddish-brown residue is obtained consisting chiefly of a crystallisable volatile acid.To purify this acid it is sublimed in a retort in order to separate it from the accompanyitlg non-volatile resin. By repeating this operation several times or by recrystallisirig the sublimed acid from boiling water it is obtained in white indistinct needles or plates having the coniposition of benzoic acid. If we neglect the formation of the red resin the formation of the benzoic acid may be illustrated by the following equation :-C1$HI1N&?( + 2CZHGO + NHOj = 2C7H,jOL + 2CaH40 + 2HzO -I-4N. Alcohol. Benzoic Aldehyde. acid. Action of Ammonia upon Diazo-amidobenzoic Acid. Diazo-amidobenzoic acid dissolved in dilute aqueous ammonia is easily decomposed on boiling with evolotion of nitrogen gas. If the dark reddish-brown liquid obtained be evapo-rated on the water-bath and treated with dilute hydrochloric acid a reddish-brown amorphous body is precipitated whilst the mother-liquor contains a second product of decomposition.The red body is purified by dissolving in alcohol precipitating with water and desiccating over sulphuric acid. Tt is a red amorphous powder insoluble in water and ether but easily soluble in alcohol. It possesses the character of an acid dissolving with facility in alkalies from Tvhich it is reprecipitated by acids. A neutral soh- tiori of the acid in ammonia gives brown amorphous precipitates with solutions of' metallic salts. I have not determined its corn-position." The niother-liquor containing the second product of decomposi-tion is evaporated and the chloride of ammonium precipitated by * Relying upon a single combustiou I had set lip for this body the formula CI,HI,,05.I have since found that it contains nitrogen; and I intend to submit it to investigation at some future time. ORBASIC COMPOUNDS E’I’C. 311 dichloride of platinum. The precipitate is filtered off and the filtrate saturated with sulphuretted hydrogen ; the sulphide of platinurn is separated; and the solution evaporated on the water bath. The residue consists of amido-benzoic acid combined with hydrochloric acid. Exactly the same decomposition takes place when diazo-amido- benzoic acid is acted upon by a dilute solution of potash. I have performed the experiment just described in many differ- ent ways.Nothing appears more simple than to suppose that diazo- aniidobeiizoic acid under the influence of alkalies splits up thus Cl4Hl1N3O4-I-H20 = C7H603+ C7H7N02+ N2. There would accordingly exist in diazo-amidobenzoic acid that is in its pre-existing atomic group C,H,N,O, an intermediate body by means of which it might have been easy to step from the amido-acids to the corresponding oxyacida. However all the experiments I have made with this object have failed the result being always amidobenzoic acid and the same red amorphous borly . These facts give a sufficiently clear representation of the chemical deportment and the nature of diazo-smidobenzoic acid. I might have considerably increased the number of products of decomposition as there are matiy other bodies which induce an alteration of diazo-amidobenzoic acid ; but in order not to extend the limits of this investigation too far I have preferred to abstain from communicating further experiments made in this direction.DIAZO-AMIDOAN JSIC ACID. Anisic acid although not standing in the same homologous series with benzoic acid yet exhibits a great auslogy with it in its whole chcmical and physical deportment an analogy which is sustained throughout nearly all the derivatives of both these sub-stances. It mas to be expected that amidoanisic acid under the influence of nitrous acid would be converted into a compound possessing those properties which are so characteristic in diazo-amidobenzoic acid. Experiment has entirely confirmed this supposition.Thct new compound is obtained by exactly the same method as that 312 CJRIESS OK A NEW CLASS O@ employed for the preparation of diazo-amidobenzoic acid. A current of nitrous acid gas is passed into a cold saturated solution of pnre amidoanisic acid or the latter is treated with an ether of nitrous acid. In both cases the substance required separates as a yellowisli green amorphous powder; it is collected on a filter and purified by repeatedly washing with alcohol. It deserves here to be particularly noticed that in order to ensure the success of this experiment it in above all things necessary to operate at a ioiv temperature and carefully to avoid an excess of nitrous acid; as otherwise the desired substarice is not even always formed and if formed is re-dissolved with the greatest facility and con-verted into another product.The latter phase is at once recog- nised by the commencement of an evolution of gas as well as by the appearance of a deep brownish-red colour. It is best not to operate upon large quantities and the operation siicceeds well if the solution of amidoanisic acid is introduced into a number of test-tubes and these severally submitted to the action of nitrous acid. The separate portions may then be mixed and purified as before described. The formation of the new substance takes place tlius :-Amido-anisic acid. New acid. One glance at the mode of formation and at the few properties already known of this substance suffices to stamp it as tlie true analogue of diazo-amidohcnzoic acid.I have called it diuzo-anlido-nnsinic acid and consider its ratioiial composition to hexpressed by the formula,-It presents itself in the form of a yello~ or @reenisli-yello;v amorphous powder and but seldom exhibits traces of cry. etalline form. It is insoluble in water as well as in alcohol and ether. Powerful acids dissolve it though not mitliout decomposition. In aqueous solutions of the nllialies or1 the other hand it dissolves without altcration if tlie temperature be kept bclow thc boilitig point. Weali acicls precipitate from tliese solutioiis the original siiljstance as a ycllow gc3l:ttinous mass. It may be drid at looo jyitilout dwger and is decoml)os;rd OillJ-at ;X coilsidc~iil,i~ higher OEGANIC COMPOTJNDS ETC.313 temperatiire. Heated 011 platinum-foil it defligrates slightly tlie residue then melting and burning qaietly with a smoky flame. Salts of Diazo-amidoartisic acid.-Diaza~amidoanisic acid is a double acid which like its analogue in the benzoic group always combines with tno equivalents of metal. Its salts are partly of great beauty; and whilst possessing but little stability when in aqueous solution will when dry bear a temperature exceeding 160'. Its salts with the alkalies are alone soluble in water the rest forming almost without exception yellow or greenish- yellow precipitates. The potassium-salt C,GH13K,N306 is obtained by dissolving the acid in an excess of carbonate of potassium. If the tempera- ture be maintained below 80° nothing but carbonic acid is evolved ; the solution assumes a yellowish-green colour.On cooling the salt is deposited in golden yellow oval plates ; they are collected on a filter and washed with very dilute alcohol until it runs off nearly colourless. In order to recrystallise this salt ft process which is not always successful it is dissolved in the least possible quantity of water at about 80° from which the greater portion separates on cooling. It is scarcely possible to obtain the remainder of the salt by concentratiiig the mother-liquor as on doing so an evolution of gas soon commences; tlie colour of the solution also changes from yellowish-green to a deep brownish red thus in-dicating the decomposition of the substance.The salt when dried over sulphuric acid has the composition C,6H,3K2~,06.2H20. The water of crystallisation is expelled only at about 169O. The crystals especially when floating in the solution exhibit a vivid scintillation resembling crystallised iodide of lead suspended in water. The salt is easily soluble in warm water; difficultly soluble in a concentrated solution of carbonate of sodium or potassium ; insoluble in alcohol and in ether. From a concen- trated aqueous solution it is precipitated by alcohol as a light yellow powder. It deflagrates at 180'. Its solution in water has no action on vegetal colours. Diazo-amidoccnisate of sodium ClBH,,Na2N,O6 is prepared in exactly the same manner as the potassium-salt which it resembles in all respects.It crystallises in well-defined six-sided plates of a golden-yellow colour and is less soluble in water than the potas- sium compound. When dried over sulphuric acid it still retains 18 molecules of water of crystallisation. nin,-o-niiLi~oanisate of uiimonium forms readily s:oluble golclcn- GKIESS ON A NEW CLA$SB OF yellow pIates. The aqueous solution is rapidly decomposed by ebullition. Magnesium-salt. -Greenish-yellow globular masses of crystals difficultly soluble in water. With the alkaline earths and the metals diazo-amidoanisic acid forms insoluble or nearly insoluble salts which separate as yellowisli-green gelatinous masses. Diazo-umidoanisate of Ethyl C,6H,3(C,H,),N306 is obtained by acting upon an alcoholic edution of amidoanisic ether with nitrous acid.If a moderately concentrated solution has been employed the new ether at once separates in small crystals By separating the mother-liquor and recrystallising the substance from alcohol it is obtained perfectly pure for analysis. Diazo-amidoanisate of ethyl is easily soluble in hot alcohol ;the greater part of it crystallises out on cooling in the form of long narrow plates of a yellowish-red colour. Nther likewise dissolves it but it is insoluble in water. It is not volatile without de- composition. When heated on platinum-foil it fuses and gives off volatile products of decomposition and finally burns with a smoky flame. The new ether possessea the character of a weak base; it dissolves very sparingly in dilute acids and is repre-cipitated by ammonia.Concentrated acids and alkalies decompose it in the same manner as the free acid. Diazo-amidoanisate of Methyl C,6H,,(CB3),N306 is obtained from amidomisate of methyl in exactly the same manner as the ether mentioned before. It forms yellowish-red plates which in nearly all their properties resemble the preceding compound. Products of decomposition of Diazo-amidoanisic Acid. In its deportment with reagents diazo-amidoanisic acid exhibits the same mutability as the correspondiug compound in the benzoic group. 'The resulting products of decorriposition are throughout analogous to those of diazo-amidobenzoic acid. I will here give a short description of a few of them. Decompositioiz with Hydriodic Acid.-On heating the new acid with hydriodic acid lodankic acid C,H,IO, and hydriodate of amicloanisic acid are formed with abundant evolution of nitrogen.The first compound separates as a reddish crystalline mass whilst the ORGANIC COMI'OUPI'DS ETC. latter remains dissolved in an excess of hydriodic acid. Iodanisic acid when perfectly pure appears in the form of exceedingly small needles almost insoliible in alcohol ether and in water. Hydriodate of amidoanisic acid obtained by evaporating the hydriodic mother-liquor is extremely soluble in water easily soluble in alcohol. It crystallises in plates or needles and fre- quently in star-shaped groups. The trausformation of diazo-arnidoanisic acid under the influence of hydriodic acid is repre- sented by the following equation :-It is remarkable that the decomposition of diazo-amidoanisic acid by hydrochloric and hydrobromic acid is totally different from that with hydriodic acid.No traces of chloranisic or brom-misic acids are formed ; the resulting products are arnidoanisic acid and a brownish-red acid insoluble in water which I have not yet thoroughly examined. Exactly the same products arise when a solution of diazo-amido-anisic acid is boiled for some time with an alkali. Chlorine bromine and iodine also act upon diazo-amidoanisic acid; the products which arise I have not yet examined ; neither have I followed up the transformations which the acid undergoes under the influence of sulphuric and nitric acids. Action of Nitrous Acid upon Diazo- amidoanisic Acid in the pre-sence of Alcohol.-When suspended in boiling alcohol and treated with a current of nitrous acid gas the new acid is rapidly decom- posed with evolution of nitrogen.Orr distilling off the alcohol a residue is obtaiued consisting of an acid which when re-crystal- lised in order to separate it from a resinous body with which it is mixed appears in the form of small prisms exhibiting all the pro-perties of ordinary anisic acid. Its formation takes place thus :-C16W15N306 + NHO2 r 2C2H60 = 2CgHy0.4 + 2CiHJO + 2HBO + Nj. Anisic acid. Aldehjde. The experiments just described will suffice to show the intimate relation which exists between diazo-amidoanisic acid aEd diazo- amidobenzoic acid. In fact there are but few bodies to be found which exbibit so great an analogy both in their physical arid GRIESS ON A NEW CLASS OF chemical dcportment.This analogy is carried to a still higher degree in tbc following compounds so that it would be but a repetition of the previous pages to enumerate their properties in detail DIAZO-AMIDOTOLUYLIC ACID. The preparation of this compound from amidotoluylic* acid is identical with that of diazo-amidobenzoic acid. Its formation takes place according to the following equation :-Tt crystallises in yellow microscopic prisms which diffcr from the crystals of diazo-amidobenzoic acid only in their superior size. It is insoluble in water as well as in alcohol and ether; acids dissolve it with decomposition; the alkalis on the other had dissolve it without alteration.When heated on platinum foil it deflagrates and then burns with a smoky flame. It is inodorous and tasteless. I have made only a few qualitative observations on the salts of diazo-amidotoluylic acid. Diazo-amidotoluylate of potassium forms a crystalline mass easily soluble in water. The same may be said of the sodium- and the ammonium-salt. The aqueous solution of the latter especially is easily decomposed on ebnllition. Diazo-amidotoluylate of barium prepared by precipitating the ammonium-salt with chloride of barium is a yellow precipitate insoluble in water and in alcohol. Diazo-amidotoluylate of silver is also a precipitate which on account of its gelatinous nature can be separated only with difficulty from the mother .liquor.* The amidotoluylic acid was prepared from Noad’s toluylic acid. I still con- sider‘this acid obtained by the oxidation of cymene by nitric acid as the true homologue of benzoic acid in spite of the reasons brought forward by Strecker and MijlIor (Ann. Ch. Ph. cxiii. 67) against thisview. For although these chemists relying on observations of the melting point and the form of crystallisation of the toluylic acid discovered by them pronounced it to be the true homologue of benzoic acid jet the deportment of their acid with certain oxidising agents with which it yields oil of bitter almonds is equally against this view. The manifold derivatives of Noad’s toluylic acid which I have prepared and which are scarcely to be dis-tinguished from the corresponding derivatives of benzoic acid will assist in restoring this acid to its original place in the systcm.t-1RO.1NTC COT19PO UNDS E:TC. The transformations of diazo-amidotoluyiic acid under the in-hence of reagents have also only been qualitatively investigated ; they resemble in every way the phenomena described when treat- ing of' diazo-amidobenzoic acid. Nitric acid converts it into a yellow crpstallisable acid easily soluble in water and in alcohol and which is in all probability homologous with trinitro oxybenzoic acid. Nitrous acid converts the new acid when suspended in water into derivatives of oxytoluylic acid whilst when suspended in alcohol it yields an acid which is no doubt identical with toluylic acid.Hydrochloric acid gives rise to the formation of chZorotoZuyZic acid and hydrochlorate of amidotoluylic acid with simultaneous evolution of nitrogen. Hydrobromic and hydriodic acids give rise to perfectly analogous decompositions. The iodotoluylic acid thus obtained crystallises in delicate white plates or needles with difficultly soluble in water easily soluble in alcohol and ether. It greatly resembles iodobenzoic acid. Its formula is C,H,IO,. DIAZO-AMIDOCUMINIC ACID. This acid of all those jwt described is the most difficult to obtain. Its preparation _succeeds best in a test -tube surrounded with ice and containing an alcoholic solution of amidocuminic acid into which a current of uitrous acid is passed great care being taken to avoid an excess of gas.It is best to stop the current as soon as the solution begins to become turbid from separation of crystals. On allowing the liquid to stand for a short time the whole of the new substance formed is deposited. It is collected on a filter and purified by washing with cold a1 cohol. Diazo-amidocuminic acid crystallises in yellow microscopic prisms or plates nearly insoluble in cold alcohol quite insoluble in water. It is the most unstable of all the analogous compouiids just described and is decomposed with evolution of nitrogen on merely boiling with alcohol. It exhibits however all the charac- teristic reactions of the double acids previously described. Diazo-amidocuminate of barium is a yellowish-white amorphous powder.Diazo-amidocuminnte qf silver fdls as a yellaw amorphous T'OL. XVIII. 2A 318 QRIESB ON A NEW CLASS OF ORGANIC COMPOUNDS. mass on treating an ammoniacal solution of the acid with nitrate of silver. APPENDIX. When describing the preparation of the different double acids the necesaity has always been pointed out of maintaining a low temperature and avoiding an excess of nitrous acid. The formation of these diazo-amido acids does not take place at all if a large excess of nitrous acid is brought in contact with a hot alcoholic solution of the amido acids. In this case a per-fectly different reaction ensues; the atomic group NH, which is supposed to exist in the amido-acids is simply replaced by one atom of hydrogen.The other products are water aldehyde and nitrogen as shown in the following equation -C,H,(XHZ)O + NHO + CzHGO = C'sH,O;1 + CBHAO + ZHLO + N2. This decomposition succeeds best in the following manner :-Al- cohol previously saturated with nitrous acid is heated to ebulli- tion and the solution of the amido-acid then added whilst a con- tinuous stream of nitrous acid gas is passed through the mixture. The liquid generally assumes a brownish-red colour whilst a vigorous evolution of nitrogen takes place and continues until every trace of amido-acid is decomposed. As soon as this point is reached the excess of alcohol is distilled off and the resi- dualy acid which is generally of a reddish colour is purified by recrystallisation and sublimation Each of the amido-acids which I have examined up to the present moment may in this manner be converted into an acid identical with that from which the amido-acid may be supposed to have originated by nitration and subsequent rednction.This following formula?will illustrate this transformation :-C*H& Anisic acid. C,H,(N02)0 Nitranisic C,H,(NH# Amidoanisic C,H,O,. Anisic acid. acid. acid. ~7H60 C7HdNOJO2 C;H&NH,)02 c;Y60;. Benzoic acid. Nitrobenzoic Amidobenzoic Benzoic acid. acid. acid. C6]E-I4(NOp)aO C~H~(NO.&&I C~,H,~NOX);(NH~)O C6H4(NO,),O" Dinitrophe-nylic acid. Trinitrophenylicacid. Amidodinitrophe-nylic acid. Dinitrophenylic.acid. * See page 270 of thifi journal.