1264 SAUNDERS SOME NEW CXXXV1.--Some New A xop yrazolones and Allied Compounds. By KENNETH HERBERT SAUNDERS. IN seeking t o asmirt'ain the eiffecit procduced on the co3our of com-polunds of the a,zo-typel belonging to the1 benzene naphthalene and anthraquinone grolups b'y inmelasing moleculas weight by a corn-pa,risoln. od the abslolrption spectra' o,f the various members it was folmd that sca,rcmly any of the required substa,nms beyond t'he belnzeiaeazol- a'nd na~ht;halane;a~o-selrias have be'en prepared. Alth,oagh a,zobenzelneI arnd the a,zonaghthalelneis are. very well knolwn a-azoa,nthra,quino~ne ha's ,olnly beten disaomreld in recelnt yelam (Gattelrma,nn a8nd Eberti Ber. 1916 49 2117) whilstl the a.zoa,nthra,aenes a,rei unknolwn. For the1 purposel oif such a' oom-pa,rison the azopyrazollones being more strongly coloure4d and much f a8ster to1 light tha,n t'he c,orreaponding membelrs of the! azobenzene series woluld seeelem t,ol be more suitahlel and haw therefocel been se;leateld for the investigation.A clolmpleta series of co8mpolunds ha,s been preparead in whic8h the ant'hra.quinolne1 nucleus is intro-duwd e1ithe:r into the 1-position of the1 pyrazolone ring or as tthe first colmponent of a,n amzopyramzolonel compolund or in b0t.h positions tcogether. The 1 -a,nt8hraquinonylpyraxo~lones cannot be ob,t8ainemd by the simple prolaess of he:a,ting ethyl amceltioa~ceta8te with the relquired h y d r axi nei bemuse' rea#ction inva'r i ably s t,op s with t,he f osm a,ti on olf the hydra.zone. The further action olf condensing agents is nelceesary before tlhe fl-anthra#quinonylhydrazons of ethyl amto-acetlats can be convelrteld into a.pyrazolom. Although bo,iling sulphuria a,&d will elffect tlhia change' in one stsagel t,he yield of the pyrazolone is sma(l1 a large proportion od tihe original hydra(zine1 b,eing rege,nelra;t;ed. A far more satisfa<otory method is to! b,oil the hydralzolne with acetic anhydride( wherebsy l-P-a,ntfhra.quinonyl-5-a~~tyl-3-me~thylpyra~zolone~ is produoeld (Mohlaa and Re'iner Ber., 1912 45 2244> and tlhsn hydrollyse with hydrochlorio acid. 1 -P-Anthra~u,~Onyl-3-methy~-5-1ryrarzolo~e is olbtaineld in tlhis way 8.5 an olrangei powder showing all the! propertiels of the cla.ss except tha,t the a,ntlhra8quinona n u o h s causes i t to1 be highly insoluble and rather slow to enter int'o relaction.It aouplee with diazonium salts in a,aeltic a,cid solution to1 give t-ypical a,ryla.zopyra.zodones od great stability which do not sho'w delfinite melting pain& but slowly begin to deloo8mpose abomve 250° olr thereatbout'. The so3e prolduct of the1 compbtel conde.nsa,ticm of the a-a.nthra AZOPYRAZOLONES AND ALLIED COMPOUNDS. 1265 quinonylhydrazone of ethyl aaeltoamt-ate is pyrazoleanthrorie and the required pyrazolone cannot be obtained (Reiner Diss., Dresden 1912; Mohlau and Viertd Ber. 1912 45 3238). Difficulty i n obtaining the a-isomeride is also1 expelrienceld in the preparation of the l-na4phthyl-5-pyrazolones (Knolrr Ber. 1884, 17 550) for whilst l-j3-naphthyl-5-pyrazolonel is easily prolduoeld, t!he produd olbtained from the fusion of a-naphthylhydrazine with ethyl acetoacetate contains scarmly any pyrazoloine whilst in solvent8 the colndelnsation does not take place1 at all.As noted above the colour of P-anthraquinonylpyrazolone is orange althoagh all the ohher pyrazolonels olf this type1 hitherto described are1 colsur-less. The colour vibration may be selti up by tlhe carbonyl group off the pyrazolone reacting with that of the anthraquinone nucleus, owing t o their being so a,rranged in space that they are in the closssb proximity. Thatl the1 colour is concerned with these1 two1 groups is shown by the fact that amtylation od the pyrazolone changes the collour t a lemon-yellojw. It seems possible thereforel, that the codour of the produde and also the diffiaulty oif intro-ducing the a-anthraquinonyl group may be referred to1 the con-tiguous position od the carbonyl groups in the anthraquinonel and pyrazoilone nuclei.Evidenoei f o r this view vmuld be1 the pix-pa,ra;trion od the 1-a-naphthyl- and l-a-anthraquinonyl-3-pyrazolone, but thew compounds do1 nolt yet seem tot have! beleii described, For the preparation of the arylazo-derivatives of the abovb anthraquinolnylpyradonei the alternative process due to1 Bulolw and Helcking (Ber. 1911 44 437) has also beein investigated. The first two 5teps are easily accomplished P-anthraquinone-diazonium sulphatel for example readily combining with ethyl acetolamtate whilst the1 azol-compound so formed o n boiling with hydroxylamine passe@ inta the isooxazolone.When however the isooxazolone is treateld with hydraziiies although a yield approach-ing theoretioal is olbtaineld from hydrazina itself the yield steadily falls as phenyl naphthyl and anthraquinonyl nuclei are introl-dumd so that the1 methold is useless for produ-cing the higher members of the series. Sodium dihydroxytastratel dscomposss below a temperature a t which P-anthraquinonylhydrazine will mad excepting with extreme shvnelss so thatl it1 was found impossible to olbtain new members of the tartcazins group by this method all products of readion. from a large variety of solvents beling for ther most part a mixtlure of the decompoaitioln proiducts of the dihydroxytartrate . The antlhraquinoinelazopyrazolones whether unsubstituted in the 1 -position olr substituted by phenyl naphthyl o r anthraquinonyl rwidues are1 aharauterised by having at best only a sparing sdu 1266 SAUNDERS SOME NEW bilitly in most osga.nio solvents.They can be ary&allisd fairly well from pyridinei or nitrollsenzeiiel. They also ham t~he property oQ many anthraquinonelaz&compolunds of dissolving in warm alkali hydrolxide to1 form a deep purple solutio'n a<nd in the case of 4-B-ant hra;qu,imomneaz 0- 3 m e t h y I- 5 -pyratz o h o.rz.e w hi oh is very reladil y soluble1 in this reagentl a rnolnosoldim saltl can be mystallised by saJting the wa,m. sollutioin. Thelir melting points a<ret very high so, t8halt o 4 t a decompoaitioln 14eltls in bef o'rel fusion t,akels place'. The prolpelrty which firstl atlt'racted a.t,tentlion t o the group is tha't 4-~-anthraquino~ne~azo~-l-phenyl-3-met~hyl-5-pyra~zolone can exist in t'wo differelntly cololured moldificat'ions (1) yedlolw unst,ablel, and (2) red stable (Mohlau and Relinea Rer.1912 45 2240). These ant'holrs prepared b,otlh forms and forund tha't the same absorptioln speotrum is give'n by both a8nd tfhat on hela.t.ing the ydhw foran. chafnge.s into the1 md withoat melltling. The sa4me behaviour is sholwn by 4-~-amthra~purin~om~ca~zo~-l-~-naphthyl-m.ethyl-5-pyrazo~lo.ne esce'pting that1 tlhe yelllolw form is still less stlabmle a,nd oinly appeers direlotlly a.f telr colmbination ha,s ttakeln place', rapidly cha-nging tlol the md fo'rm. oln wa'rming. On th0 olthelr ha,nd 4-~-antlhra~quino~nea~z~-3-methyl-5-pyra~zollo~ne~ and 4-P-mt hra-quin8mleaz ocl -P-ailz,tIzrai~ui/n,~ln.~yl- 3-methyl-5 -pyraz crloin,e exist in the solid stlattel only in yelloiw forms and by no means ca,n be induced ta crystallise olthelrwiss.It1 would a,ppear t8hhereifoirel thah a phenyl a,nd molrel partimla8rly a napht,hyl nucleus substibutling the 1 -pit,io'n olf tlhe; pymzollolne ring causes the ordinary yedlolw form t'ol be unstable( with the1 result that slightl re8arrangsmenb takes p1a.m on crystlallisa,tioa a rno're st'able reld f olrm being produced. The eolour olf tlhe s,olutiolns od the amnthraquinonea,zopyra8zololnea is deep yellow almolst indistinguishablet to1 t'he eye from those! of the( benzeneazopyrazollonea the am-colmpoiunds derived f rm l-~-ant~hraquino~nyl-3-me~t~hyl-5-pyra~zo~lo~ne noIt.withst.anding t,he red cololur of this compound shotwing practically the1 same colour as those in which the a,nthraquinone nucleas is absentl f r o m the 1-position of the pyrazollonel ring.This agrees well1 with Hewitt's bheolry (T. 1907 91 1251) since the t'wot aarb'olnyl groups in the ant.hraquinotne1 nudelus cut shojrtl the chain oif double a7nd single bolnds isollating the benzelnel ring beyo,nd sol tha8t~ it1 c,a.nnolt add its e)ffe,ct acrid thus ths nelt rea,ult+ on the1 cotloar of an anthraquinone group in a,n a,zol-c:olrnpoand of this type is pradioaslly t,hat' of a single be,nz.ene ring. I3 x P E R I M E N T A L. &A I t tki*uIT'iiiiO~i,!ilh~lrJ1.azi?i e.-For the purpose oif this reeeaarch, a considerable quantity of tlhis hydrazinel was required. Th AZOPYRAZOLONES AND ALLIED COMPOUNDS.1267 synt.he&s has been described in detail by Mohlau Viertel and Reiner in a comprelhensive paper (Ber. 1912 45 2233) and also by Mohlau (&id. p. 2244). The1 latter paper delals wit.h the pre-pasa.tJon f rolm P-ohloroanthraquinone by heating with hydrazine hydra,& but as the yielldsi ase olnly about 20 pelr celnt?. the process is useless on t,hel la'rge sca'le. The1 fotrmelr paper is a,n account otf the1 process oatdineld in D.R.-P. 163447 consi&ing in the reduction of P-anthraquinonediatzonium su1phat.e in aqueous so1utio.n with potassium hydrolgeln sulphitei f o'llowed by hydrollysis od the hydraaineldisulpholnic a#cid wit,h hydrochlolric a,oid. Owing ts t'lie fact that all the1 intelrmeidiatel compounds ha,vel to be isolated in t'hei sollid stla.te! the proow is lengthy a,nd cumbelrsomel on accolunt~ of the ra4t,helr large volume of water nelcessary f o'r the1 spasingly solu b,lei P-a<nthr a8quinonediarzoaium su1pha;te.T he1 relduct ioln o:f t he1 diazonium chloride with &annous chlolridel has the'ref o'rel been trield. If p-aminoa,nthraquinolnel is boiled wit'h excess of coaclent'rated h y d ronhlolr ic a clid un ti1 comple,tedy convelr ted t'ol the hy d r olclhl o'ri d e, it aa,n b,a dia.zoltise!d a.6 the1 ordinasy tempesakure as recrlily a.s i n concent8rated sulphuric acid. ColmpletJon is shown when a. drop oif t,he liquid diluted witlh water gives yellow diazomnium sulphate, soilublei oln shaking inst The1 a,&don of stannoas chlolride on such a solution is compleix and leatds to poor yie,lds of P-antlhraquinolnylhydra,zinel.Even whe8n strongly cooled wit'h ice and salt' nit'rolgen is emollved during the reacltioin and tlhel tot'al nit,roigen coatsnt olf the final prolduct nelver rises above 7.5 per cent. This seems to be duel to1 at t'wo-folld causel. First the ant:hraquinone-aarbolnyl grotups are more easily reduced tlha.n the diarzo8-group a,nd secolndly st'erio hindrance causa the getnelra'l sluggishness of the1 a-hydrogen in the1 hydra'zine, reduoing agelntls noit being able t'o a4dd this hydrolgeln thus musing fissioin of the dia,zonium chloride t'ol t'akei pla,oe instread. Itl was further found that the a.dditi0.n of one1 molecule1 o'f st,annic chloride ca,useid the reactioa t,o pro,ceed more smoothly a gre,en int,elr-meldiatel produet beling folrmetd but on isollating t,hhs free1 base! it gave no1 b'ettea results oln analysis.The hydra.zons prepreid from this hydraxine was purified oaly with difficulty a,iid finally t'he b,ulk off the hydra,zinei was preparetd by t,ha use of po,t,assium salts, whiclh give bettelr yiellds aad morel uniform results t,han those 0.f sodium a c:onst.antl yielld of 70 per cents. being obtained. d of a,minolant,hra,quinonel in reld flakels 1268 SAUNDERS SOME NEW P-Anthraquinonylhydrazinet was co,ndeaaed with ethyl aceto-ace.tafe in amyl alcohol sollution and the hydrazonei recrysta,llise.d from a h h o l . Ten grams of this boileld with 100 C.C. olf acet'io anhydride gave 7.5 grams olf t'he a,wltylpyra.zolonel which was dis-sollved in a mixture1 oif 200 e.a.olf glaoia.1 a,c,etic a.cid and 75 c . ~ . od hydrochloric a,cid and hydrolysed by two hoiurs' boiling lamt~telrly with t'he addition of animal chasaoa\l. The1 mixturet was coole'd, filt8elred and polureld into1 elxmss of wafelr when 1 -P-an,th1"a,qzcino.nyI-3 -met h yl-5-pyraz o1on.e selpa8r afeld as a yellolwish-r eld gella,tinous mass whioh was wa,sheId ma,ny times wit'h colld watelr and clried at, looo. The yielld wa6s 6.5 grams. . The pyrazolloae is so3uble in glacial a.cet,ic acid to1 an orange solution which deposits minuts red crjmtals otn coolling mom re.a,dily sol in pyridine but only sparingly sol in alcohol1 and momst, &her organic so'lvents ; insoluble in wa,te.r dilute acids or allia,lis, but giving a reld solution in concentra4t'eld sulphuric acid and a polrt-wine ooloaretd vat in a,lkaline hyposulphite.It wa8s recryst.alliseld from pyridine giving an olrangel powder, but a,ltholugh many co,mbustions were1 ca,rried out neithe'r satis-f aot,ory nor concolrda,nt reslulta welre olbtaineld. This woald seen t a be due to the impossibility olf effelct.ing colmpleltel combustion t3he nit,roge.n continuing t.01 bet evolveid f o r long pelriolds elven a't al bright red heat. The same trolublel ocourreld t'ol a leis de,gres with the azol-deriva,tives heIa$t.ing having t.01 be1 contdnued f oc an unusua.1 time1 before nit,rogeln oeawd to1 be evollveid. The folllowing reamctlioiis cha,ra,ct,e8ristic of the1 pyra'zolones welrej sholwn. I n acetda a,cid so<lut<ion t,hei coniponnd reta.dily rela8cta' with nitrous acid to give a spasingly sollublel palel yelllolw isornitroso.cmmpound. Bromine wa,te,r a,dde!d tot thel same1 solutdoln is atl onm det601101rised and a yedlow preIcipitlate of the dibromopyrazolonel is folrmeld. Sol far a delfinit'el memb,er of the a'ntipyrinel group ha's notl bmean obt'aineld. 4-Beltz en eazoil -P-a,mt hrapuinomy l- 3 -met lzyl-5-pyramz o b n e, To a solution od the1 pyrazolonej in glacial acetic acid the! requi-site quantity of benzeaeldiazcnium chloride was addeld. I n the! prese'nm of sodium aceitate combination a,tl once took plaml a AZOPYRAZOLONES AND ALLIED COMPOUNDS. 1269 yelllow gedatdnous mass se'pasating. After stirring f o r an hour at, Oo itl was ponreld int,o wa.ter collectsd wa,sheld and dried.It crystallisels from pyridine, in which it is ve,ry rea'dily soluble in minutq yelbw neeiclles. It is soluble1 in nit'rotbenzene and to a s,ma,llelr elxtmt in g1ac:ia.l a.celtda acid ; in concelntrated sulphuric a.cid i t gives a deep olrangs sollutioln (Found N=13.58. C,H,,Q,N requires N = 13.71 pelr cent'.). 4 - a - Nn ph t halcn e m 0-1 - p -an t h rap. uin o n1yl-3-m e t h y I - 5 -pyraz olome and 4-P-Napht halenenzo- I-P-ant hra p i n onyl-3-met hyl-5-pyramzolone, N:CMe I >CH.N:N*Cl,H7. C,,H +-I,* N-CO Thetse were prelpa,red in eIxactly t,he same way a.s t,he belnzenela.zoc compoand. The former was obtaineld in minuto velrmilion needlea 0.a crystallisat,ion frolm pyridine in which it is very sparingly so'luble (a.bout 0.75 gram in 100 c.c.).It gives a purple1 sollution in concelnt ra8ted sulp huria acid whetreas the P-naphthalelneazol-componnd is de!ep osangei in t'his solvent the1 usual test which ServeiS tot distinguish the1 two1 isomelridee no! rnatkm what the I-substltuent olf t'hei pyra,zololneI ring is (Foand N = 12.06. C28H,,03N4 requires N=12*22 pe,r cent.). The second compund beling almost insoluble1 in pyridine was cryata,lliseld from nit,robeiizelne giving a dull red po1wde:r. Bot,h are1 insoduble. in most olrgania solvents (Found N = 12.10. C,,H,,O,N relquirea N = 12.22 per cent.). 4 -p- A n. t hraqzcirzon eazo-1 -p-an t hraqi~inOnyl-3-me t hyl-5 -pyrazolome, >CH.N:N-C!,,H,O2. :CMe c1 H70,. K-co P-Aminoanthraquinonel (I * 1 grains) after convewion to the hydrochloride was diazotised in 30 C.C.of glacial acetic acid with 30 per cent. excess of amyl nitpite (Kaufler Zeitsch. Farben-lnd., 1903 2 469). This was combined with 1.5 grams of the pyrazolonei in acetio acid soilution giving a theoireitioal yield od the crude1 azol-compound. When orystalliseld f rom nitrobenzene it f o m s finel microscopic yellow needles ; variation of the conditions faileld to1 produce1 any other form. Itl is insoluble in a11 solvents except nitrobenzene and to1 a less extent in pyridine (Found: N = 10.26. C,H,,O,N requires N= 10.39 per aent.) 1.270 SAUNDERS SOME NEW 4-P - A ?L t hTaq 1 ~imoneaz 0- 3-nze t h y 1 - 5-p'y ra z d o n e r= CMe>CB N :N C',*H7* . NH-CO P-Amino8a,nthraquinoiiel (2.5 grams) was dissolved in 19 C.C. of sulphuria acid (D 1-84) wibh me,chanica.l st'irring.The1 bsaker was susroundeid witlh EL wa8ter-ja,cket8 and 4.5 grams of dry crushed ice we're added to t,hei solutiolii. I n five1 minute,s a volluminous, white pa,st,el oif P-aminola.nthra(quinone1 sulphat,el was folrmeld. A so1u.tion olf 1 gram olf soldium nitsitel wa,s t'hea added frolm a t.ap funnel wit,h a velry fine nolzzle sol tha't a8n holur elapsed before all ha'd beeln run in whilstl tlhel ttempelratturel ,elf the1 acid and t.he surrounding barnth wa's allolweld to1 rise to 30° under t'he helast( of dilution. As t'he diazolt<isation proceeldeld the! P-amino,ant.hraquin-one sulpha,te diasodveld md on c:o'mpleltion at cle.a#r bmwn sollution resulted a drop of which a8dded t,a waltelr7 ga,ve a yedlolw precipitate, dissoilving to1 a velry palel yelllow sollutioln 0111 shaking.Sufficient ice to d i h t e t+hel wa.rm solutioln emofugh t'ol st,ast8 the! erystfa.llisa,tion of tha fl~-antehra8quino~nedia.zolnium sulphate was a8ddeld and the whole1 set aside to1 ciool. In ha#lf an hour the1 dia'zonium salti cryst8a.llised in shining yellow plates the content's of the1 belake'r set'ting solid. The nmss wa,s sciraped outq 0;11 t'ol crushetd ice] collected and wa.shed oncei w i t,h icei- w a,te>r. The fl- a4n th r aquinolnediazonium sul p h a t,el was olbtained in this way as a yedlo~w st'a'ble crystallinel powder in a yield of 87 per ceati. olf tlhe tllielo~ret6aa81. It' was dissolved by stirring into 400 a a . olf wa,t.er a-l; 200 and decompoeed wit.h a so3utioln olf 5 grams olf soldium a,e8ttatei.Tein grams of 3-metrhyl-5 -pyra,zollone~ ha'ving bewi dissoilved in 350 O.C. of wa,tec the dia,zo-solution was addeld with st,irring and immejdia;tfelly tfhel azoI-compolund selpasa;t8ed in ye~llo~w flakes. It was colllelcteld washeld twice wit'h bolt water and drieid at looo ; t,he yield was t'he'oretioal . This colmpolund wars folund t.01 he cha.ra.oteriseb b,y extreme1 in-solubilit<y in a,ll o>rganio sollvents. Itl was crystallised from pyridine, in which it dissollveld t o the1 e,xtent o1f lem tlha4n 1 pelr clent. the crystals f o,r,ming microiscolpio nesdles. It wa,s aJsol spa,ringly soluble in nitro)belnzeael or a,myl adcoholl ; in c,o,ncentra#ted sulphuric acid the sotlutioln was oirangel (Folund N = 17.12. CI2Hl2O3N4 requims N = 16-90 pelr centl.).Whein warmeld with diluta soldium hydrolxide sollutlion it dis-so,lved rela.dily giving a deleip purple soJutioa. On sadtdng the hot, solu tiotn shining pu rplish-bl a,ck cry st'ads welrei delp osi teid and o ii acidifying a sollutiotn oIf these' the original azolpyrazollone was pre-cipit>a,t.ed as a yelllo8w jellly. By t.it,rat.ion of a solution with 0*117-AZOPYRAZOLONES AND ALLIED COMPOUNDS. 1271 hydrochloric acid using the above colour change1 as indicator it was found that the1 salt coatained one atolm of sodium. 4-p- A nthraquinomeaz 01- 1 -j3-?zaph t h y l-3-m e t h y l- 5-pp-a~ 01 one -SJ:CMe C,,H7 *N-GO >CH* N N*C ,H,O,. Four gra,ms of 1 -~-naphthyl-3-met~hyl-5-pyra~zolo8ne~ dissollveid in glacial a ceitdc aci d we're.con1 bineld w it'h thei anthr aquinoineidia,zolnium slulpha.tei prepased from 4.6 grams olf P-aminolaathra,quinone diazoltiseld a,s a,b,oIvel. The am-compolund obt'aineld a8 a' flocculeint, ora,nge mass on dilut'ion witlh. wa,t.elr was collelcteid washeid twice1 with colld waher and once with holt, and dried a.t looo'. It gave brick-reld needlee whein cryst alliseid frolm nitrobelnzeliiel in which it is f a.irly solubslei a t the1 boiling polint,. Cryst'allisatioa of t<hei cool solutJoln dilutgd wit'h a,lcoiholl ckndit;lons undelr which 4-P-antlhra-quinoneazo-1-phenyl-3-me~tJhyl-5-pyra.zo~1oae~ gives a hrga propoIrtdo,n od the yellow form fa,ileld tot givei any oltheir vatrie;ty. It is adso soluble in pyridinel or glacial aceitJc acid whilstl in a(1coholic soldium hydroxide it gives t,heI typical purplei sodutlioln ; in concentrakd sulphuria a.cid its sollut,ion is deep red (Foand N=12.46.C,,H,,O,N requirels N = 12.25 peir cent,.). Attempts welre ma,de to prepa,rel thei isolmeric 4-P-anthraquinolne-azo~l-a-napht~hyl-3-metlhyl-5-pyra~z~o~lone~ bfut the remits webre unsa,t.isf a,ct,ory a'nd a pure1 substmael was noit obtained. E thy I &Ant h.1.a,qu~~o~ea,zol~cetoacetat e , C,,H,0,*N:N*CHAc*CO2Et. The /3-anthraquinolneidiazolnium sulpha,te resulting from the dia.zoltisatioin of 10 grams of &a,minolanthraquinonel was dissoilveld in a litre of water to which were added 20 grams of sodium acetate. Tot this a d u t i o n of 5.1 grams od &hyl amltolamta8te dissollved in 39 C.O. of fl-soldium hydrolxidel was added and the1 whole stirreid unt,il the odolur olf the1 eist,elr hard dis,appela,reid.The1 yeillotw a,zol-compound being quitel insotluble in wat.telr sepra,tsd a.tl olncm a,nd wa,s c!oillelot,eld wa,shed and drield. The1 yieild was t'heolretiaal calm-la,t,ing from the a,ntihra,quinoneldia,zonium sulphate used. Thel orude substlancmei ha,d a gre,eln t.iiige butl aftes boiling with a.nima.1 cha,rcolal and recrystmatllising f rolm glacial a,celtia acid it ga,vel a, yeillow powder mellting a.t. 21 6-218O. Itl is surprisingly sollublel f o r an a,nthra,quinonei delrivative; dissollving in adaolho~l ohlolroform, benzenei t,odu elnet ni trolbetnzelnel or pyridine. Alka.li hydroxide t.urns itr purplei butl it is sparingly soluh.lei a,nd a,cids prelcipitatre! i t as a yellolw jelly (Found N = 7-84.C,,H,,O,N requires N = 7.69 pe.r cent.) 1272 SOME NEW AZOPYRAZOLONES AND ALLIED COMPOUNDS. 4-&A mt hraquiao.neaz0~3 -met h y li~o~oxrazolone, Eight grams od elthyl P-anthraquinoneazoaceltolacetate were dis-solveld in a mixture1 of 175 c . ~ . of glacial acetic acid and 25 c . ~ . of an aqueioius dutyion of 3 grams of soldium acetatel. To the warm solutian 1 -5 g r m e od hydroxylaminel hydrolohloride dissolveld in 10 a.a. od wa,ter were1 added and the1 whola was boiled for two hours when a drop no longer shoiweld a relducing action on Fehling’s solution. The cololur was then orange. Animal. charcoal was added and the whole boiled f o r a furtheir ten minutes filtered hot, though asbestos and slowly cololed.A mass of orange needle-shaped crystals was depositsd and these were1 collleoted and dried ; the yield was 6 grams. The substance! melteid and decomposed at 188-191’. It was soluble in acetio acid alaohol ahlolro~form, bnmnel o r toluene inaoiluble in water or dilute mineral acids and sparingly soluble to1 a purple1 solution in alkali hydroxide1 (Found: N = 12.01. C,,H,,O,N requires N = 12.68 per cent .). On trelating an acetic acid solution of the1 icooxazoloiiel with hydrazine so voluminous a preoipitate of 4-P-anthraquinoneazo-3-me~t~hyl-5-pyrazolone was obtained that the whollel selt sollid. This substlance was idelntified by the propertiea given above. With phenylhydrazinel al small crop olf 4-P-anthraquinonelazoi-l-phenyl-3-meltlhyl-5-pyrazolone~ was olbtaineld and identifieid by its melting point. With the1 napht?hylhydrazines the produds were t o o impure and tairry tot identify with crertainty. When 1 gram was boiled with 0.9 gram of P-anthraquinonylhydrazinel a precipitate of 0.8 gram of a reid substance was obtained. By its insollubility in all soilvent& except nitrolbenzenei and its giving a relddish-purple solution in alkaline hypoisulphitel i t was concluded that it was 4-P-ant hraq~inone~azol- 1 -&ant hraquinonyl- 3-met hyl-5 -pyrazol-one but the yield being so poor and the product sol impure( this methoid of prelparation was abandoned as beling tool wasteful of the1 valuable P-anthraquinonylhydrazine. The author wishes to elxprelss his thanks t o thel Salters’ Institute olf Industrial Chemistry f o r a Fellowship which enahled the work to he colnducted tot Sir William Pope for his inspiration and intlerest and to Dr. M. 0. Forster for his guidance1 throughoiut the1 course of the work. THE UNIVERSITY CHEMICAL LABORATORY, CAMBRIDGE. [Received Srptentbc? 1 Sth 1920.