I. Action of Hydrogen Peroxide on Aromatic Compounds. II. An Attempt to Prepare Di-Para-Di-Amino-Para-Diphenylbenzene Citation Flory, Robert Weybright (1918) I. Action of Hydrogen Peroxide on Aromatic Compounds. II. An Attempt to Prepare Di-Para-Di-Amino-Para-Diphenylbenzene. Bachelor's thesis, California Institute of Technology. doi:10.7907/zka7-6m70. https://resolver.caltech.edu/CaltechTHESIS:07092024-150922588 Abstract No abstract. Item Type: Thesis (Bachelor's thesis) Subject Keywords: (Chemical Engineering) Degree Grantor: California Institute of Technology Division: Chemistry and Chemical Engineering Major Option: Chemical Engineering Thesis Availability: Public (worldwide access) Research Advisor(s): Unknown, Unknown Thesis Committee: Unknown, Unknown Defense Date: 1 January 1918 Record Number: CaltechTHESIS:07092024-150922588 Persistent URL: https://resolver.caltech.edu/CaltechTHESIS:07092024-150922588 DOI: 10.7907/zka7-6m70 Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 16543 Collection: CaltechTHESIS Deposited By: Benjamin Perez Deposited On: 09 Jul 2024 19:43 Last Modified: 09 Jul 2024 19:44 Thesis Files PDF - Final Version See Usage Policy. 7MB Repository Staff Only: item control page

~THESIS- Part I. Action of Hydrogen :' eroxide on Aromatic Gompounds. Part II. An attempt to pre pare Di-para-di-amino- para-diphenylbenzene. by Robert W. Flory. Jlass of Nineteen Hundred and Ei ghteen. (war) De_partment of Chemistry Pasadena, Califor n ia. 1918. PART I AC 1J:ION OF HYDROGEN PEROXIDE 01:T AROMAT IC COMPOUUD3. INTRODUCTION The action of strong nitric acid and aulfuric acids upon aromatic hydrocarbons takes place as if the acids g ave a hydroxyl group that reacted with the hydrogen of the ring to form water. In t his way ni tro and sulf tonL c groups are introduced into aromatic compound.at. For example, we can write the reaction of nitric and sulfuric acids upon benzene as: 011 -t f/0#4 Q!I i f/iJ-St/;/1~ QStJ.ifl +f~O Baeyer and Villigerl in their work upon peroxides gave evidence to show that hydrogen peroxide reacts as if it contained two hydroxyl groups (i.e. HO-OR). If this is the case strong hydrogen peroxide might :prove a ready means of introducing hydroxyl groups into aromatic compounds and as water is the other product the res ult should be rather pure products. Leeds 2 has sho'Wll that when 1,2% hydrogen peroxide (2 mols) is heated with benzene in the presence of ferrous s u.lfate, phenol is one of the products formed. A maximJttll yield l. Baeyer and Villiger, Ber. 34,738. 2~ Ber. 14,975. • 2 of 15% is recorded in t his case. IVIuch workl has been done and many articles written on t he oxidation of aliphatic c ompounds (especially sugars) The action of by 2% or 3% hydrogen peroxide. strong hydrogen perixide upon the aromatic compounds is thought worthy of investigation and this paper is an attempt to prepare 100% 2 or nearly 100% hydrogen peroxide and to trv its action upon aromatic compounds. Much time was spent trying to concentrate the commercial 3% hydrogen peroxide without obtaining a satisfactory product. It was thought that the time which would be required to prepare 100% hydrogen peroxide would be so gre at that lijtle else In order to obtain more would be accomplished. practice with a purely organic research it was decided not to attempt the preparation of the 1007& hydrogen peroxide, but to take up the problem described in Part II of this thesis. 100% hydrogen peroxide is described by Wolffenstein3 as anhydrous prismatic crystals (m.p. 2°c) having a b.p. of 84°0 at 68mm. () pressure or 69.2 at 26 mm. and 3 0 a spe cific gravi,:ty of 1.458 at O . It decomposes wi. th explosive violence at the boiling point Hanriot obtained 267 vo1.l of water. hydrogen peroxide wh ich decomposed upon distillation in vacuo. Talbot and Moody2 obtained 294 vol. Hydrogen peroxide. Schilow states 3 that he obtai ned 50% hydrogen peroxide by extracting with ether a 3% solution gen peroxide containing of hydro- soda. Wol:f:fbnstein4 could not confirm Schilow'e statement but obtained by distillation at 68 mm. pressure ,d 99.5% hydrogen peroxide. He gives the following precautions as essential: The hydrogen peroxide must be feee from: 1. All alkaline reacting compounds. 2. ~very trace of heavy metal compounds. 3. Solid even if of an bodies of every kind entirely indifferent nature. 1. See note 2 page 2. 100% hydrogen peroxide would 493.5 vol. 2. Talbot and Moody, Jx. Analyt. Chem. 1892,650. 3. Russ. Phys. Chem. Ges., May, 4 •. Ber. ·27, 3307. 1893. be 4 ]1TI'ERIMEJ:lTAL A. Preparation of hydrogen peroxide. The hydrogen peroxide obtainable brands as put up for medicinal use. U.S.l'. "M.C.W."l and the was of two The 3% 10 vol. 12 vol. "Dioxygenfl. Both ' ' Came a little below the 3% standard required by the U.S.Pharmacopiea. When showed smme pressure opened, a few of the older bottles due to oxygen. This 3'}0 solution was filtered and evaporated in large flat evaporating dishes en a water bath with a large funnel inverted over it connected The to the suction. funnel caused a current of air to pass over the sur- face of the liquid and ha.'3tened evaporation. At about 20% concentration the remaining solution was distilled in a vacuum distilling apparatus at 68 mm. pressure following closely the method of Wolffenst~in2 • The vacuum was obtained by a water pump and was capable of regulation to any pressure as low as 40 mm. The receiver was a large jar with five smaller receptacles inside that could be changed without losing the vacuum. The method of Colin3 slightly modified was used to determine the hydrogen peroxide. In an acid solution the following reaction takes place: made by Mallinckrodt Chemical Works. 2. Ber. 27,3307. 3. Chem. Zeit. 9, 440 and 916. 1. "M.D.W~" , 5 2KMn04-t 5H2~ t- $H2S 0 4 ----K2S04 -t' 2M:nS 04 ,.;_ 8H20 ··(• 5 02 resc1.lting in the cre:tlhC.t ·.u ,:nof RMn.04 by H20 2 • 2cc. of hydrogen peroxide solution is pipetted into a beaker, 300 cc. water added. and 1 cc. 6N H2S04, standard1 E11n04 pipetted in slowly until a faint pink color persists after constantly stirring for 1 minute. For concentrations above 10% a _small s nmple is weighed out and diluted up to 100 cc. and a portion only pipetted out and assayed. Commercial hydrogen peroxide usually contains smalL amounts of HCl, H2S 04, H3 :P04, and HF, alumina, lime, magnesia, potash, and soda. es of Fe, If carelessly made Ba and trac- Cu, Pb, arnd I'lln may be acetanilide is present. A little frequently present as a stabilizer. The stc;ck used gave neg ~att\i'V:e tests for the heavy metals. The yield of 20% hydrogen peroxide obtained by concentrating the 3% solution on the water bath averaged about 88%. If evapora ted verJ rapidly the yield is lmr1er, and if very slowly a better yield is obt ained. :By fractional d i st ill at ion at 68 mm. pressure t 1liS app roximately 20~0 h yclro g en lJe.::· oxi dc g ives v ery d.ilute dis till a tes at fi:cs t, the boiling 1:::o int ·rises slowly and the i mp urities in the r G:~ i due bec crne so co n cent1·1::tec3.. t hat the h yd ro z-en pe roxide dee ori.1p oses end Efustillation has to 1. S tandard :?CJn04 solutions (0.2492 ancl 0.4144.lJ ) were made up a:p::;n-oxi matel y , allowed to st and. B, dr.:r or two, a:1d _s tancl. . a:cdize c1 ...a.gains, t 1Ja2C20,:j;_.,,..b Y a li :'l uot'"' method of h . ~: . ~q~t lack, ..;o ur, .. A t1 . Chem• ~a:c ..,, 40 ; . G..;:::;J ._ _, 6 be stopped. Distillates obtained we re all less tI1an concentration. Upon co .ling , the residue in the flask is discolored and f'o1·ms a sort of jelly due to im:puri ties settling out. Since a part of this jelly when filtered off and evaporated to dryness gave a non-volatile white res idne that gave nega~ive tests for organic con1>ound.s, it cou.ld not be \trte:.:acetanilioe that it resembles but r.mst be of inorganic nature at the hightr concentration. were Tv;o attempts made to extract with ether. In the first an im:pure solution containing 5lo/; hydrogen peroxide was shaken ap with ether and the layers separated. The aqueous layer assayed 417b hydrogen peroxide and subjected to di:3tills:tion at 68 mm. pressure gave a boiling point of about 77°Ca.nd a very small am ount of distillate. of 43. 95~ :nyd.rocren pe:roxide concentration. The ether layer took out 20% of the total hydrogen p e1·oxid.e and was '.J lightly discolored. '.'!hen evaporated spontaneoL1sly this ether layer lsft a brovm residue in t?le dish. In t?ie se<iond atte.mpt a 3 }6 solution was extracted with etJ,er and then the acru.e ous lay9r ev apo1·atea_ e.nd () distilled at 68 mm. pr·essure. A boiling point of 61 was obtained as against 52"v1it!10ut any extraetion. The follo wing table sllo ,7S a sumrno.ry of 1 7 1.T o. Graras / # ~2°2 1 Grams at eJ1d 5SH202 at end. yield o:'o' a,..(v :J tar-t (.~~ 1 434 2.3# 20 34.00 70 2 845 2.99 110 20.2 88 3 899 2.83 115 4 887 2.86 100 21.~~ 86 5 ,. u 945 2.99 144 17.30 88 1145 2.16 135 12. 50 '74 r/ 945 2.99 145 17.20 87 232 10.5 97.5 (~~ 8 ,;p 981 " -ff It is of in t erest to note that all carne a little below the U .s .P. re qu ire□ ent of 3% H202. extr-acted with ether t1efore evaporation. Distillation in Vacuo. 0 Pressure TTb.p. of , tenm. . . of :i.1I~0 2 in ;'}I202 in O ' rnm. i-·_r; . r:.2 2 sol 1::.. v1ater bath. distillate d.istilling li quid TY # ;,-.,I o 0 .J 70 53C 62 C . 515 64 52 62 .92 37.8 65 52 66 2.72 51. 12.4 Continued distillation of 43 grams 41;0 II202 • 64 55 C 69 C 66 61.5 80 68 70 85 14.2 64 77 86 43.97 -it to1)p ed at this p oint as cont en ts of cl.is tilling :::'lask v:ere decomposing rap idly. The residu e in flask was almost solid jelly. 8 Distillat ion in vac u o. (cont'd) :Pres su re mm . H,? • b.p. of i:":. 2 O2 ·SO 1 • T 1 n. temp. of water bath . H20 2 in d.iatillate. % I 68 52 °c s5"c .8 70 54 68 1.2 68 60 76 3.0 ( 54° - 60} 68 60 78 6.5 • (60 b • p •) Extracted tv10 1 lb. bottl es ·of hydr ogen pe1·oxide with et h er, evap orated on water bath , end d.i stille d in vacuo the res u lting 232 g r ams of 10.. 5~-1:- hydrogen :pe roxide. :Pressure mm . Hf; • b. p . of temp• of H202 sol 'n. water bath. ., '%202 in distill:ate 65 47C 60° 0 to 65 48 66 .23 68 49 71 .60 II 65 49 69 .68 " 62 56 71 2.20 68 61 72 9.2 rt II St oppe d dist ill ati on here as solut i on YJUS decoop osing rap i dly. E . Action of' strong hydrogen peroxide _o~ phenol and a.nm.line. Since no sat isfact ory results were the distillations and no v.rorkab le am olmts secured from ~ of concentratea_ hydro gen peroxide were obtro ned •t ~1is part oo ns is ts only of a few tes t-tube er;eriments the results of wh ich are inc on- 9 cl us iizie. The strongest silllutions we re the residues in the dis tilling flask and were of neces s ity t he r:1owt impure. '.I.1he mixtures obtained were not analysed as they were s mall in amount. 1. Action o f ferrous sulfate on strong__EX9£~~gen peroxide. Leeds 1 used ferrous sulfate as a catalyst in obtain- ing phenol from benzene. As he used only 1. 2% hydrogen per- oxide the purpose of this pxperiment is to ascertain the stability of strong hydrogen peroxide in the presence of ferrous sulfate. The addition of 2 drops (23% ferrous sulfat e solution) to lee. of 17.3% hydrogen peroxide caused rapid decomposition resulting in the formation of 51 cc. o2 . Complete decomposition would Res ult, 51/57.4 give 57.4 cc. 89% decomp osition. Action of strong h;y:_dr9,g_en peroxide upon phenol. 2. Tvrn grams of 4470 hydrogen peroxio.e were added to 1.2 grams molten redistilled phenol (b.p. 182.6°C). The next day the solution had turned redder. There were still two definite layers of nearly the same volu.me as the ori glhnal, so it seems no considerable action had taken place. The addition of a little c oncentratedssuliuric acid turned the oo lution black, due to charring. 3. Action of 44~b hydrogen perchxide .ui;)on/ a:hd.lin'e . 2. 4 grams 447G hydrogen peroxide added to 2. 7 10 grams aniline. peroxide did:'. :,1ot decompose noticeatily. The two layers upon standing so })robably 4. 5. 6. The mixture turned brown but the hydrogen had the same relative volumes as at start little if any action had taken place. Action of 60 7~drogen peroxide upon aniline Sulfate. To . one mol aniilline added 1/2 mol sulfuric acid. · until solid vmite aniline sulfate was formed. 1 mol hydrogen peroxide,::e2 mols ~- ana.. . a ,.:,large ,:·.exces!h:ef hydrogen peroxide was added to the solid aniline sulfate in the three different experiments. In each case the hydrogen peroxide had to be added slowly and the solution co~led to avoid heating and rapid decomposition. delicate blue, The solution at first turned a then darker as the sulfate dissolved, and finally turned black. If a long time is taken the action can be completed and no rapid decomposition noted. If allowed to heat up the mixture boils vigorously, and the action becomes almost explosive in its violence. No analysis of these black mixtures was attempted. because of the limited amounts at hand ani the impurity of the hydrogen peroxide used. To obtain an a.:ihalyzable amount would have necessitated preparation of fresh amounts of concentrated hydrogen peroxide, which did not seem advisa'tle with the limited time av:3.ile.ble. 11 S UivIMA..-qy A.r""ID COUCLUS IOlilS It was thought that strong hydrogen peroxide, above so%would act as a very good method of introducing hydroxyl groups into aromatic compounds. Attempts to prepare c oncentrated hydrogen peroxide by distillation of commercial 3% hydrogen peroxide failed due to impurities decomposing the solution$. Test tube experiments with thes e impure resddues gave no conclusive res Qlts. The conclusion is reached that: i. A concentrated solution of hydrogen peroxide if pure wo uld be stable enough to work with. 2. This work has produced no evidence tending to sh ow that the proposed method wi 11 not be success- ful. 3. To obtain other means this pure hydrogen peroxide some than evaporating the commercial product mu.st be used. PART II The diazo dyes are derived from di az o bodies and from phenols, :ini:nes, o:c t:1eir s 11lfonic acicl:3. I'henyl dj_azonium ch loride ( or cl iazo benzene chloride) aid ~-n r:-r: th ol ~rn. l f onic a cid f orm ~-nap-thol-2-a z o-1Jenzene. tetra- ~ i 13y diazotizi n 0 ben z i dene, lTII2CGE _c6E4rrn2, 4 1 has is o- d i p h s nyl-c h lo r ide f anned. G. Sch u ltz f:lho wn t h a t h enzidene ~1.a s the s tnlcture: 'l1 hen co n c o red, U:.e ,-onden ~H:>.t j cn pro(._ctct of 1 rnol tetrazo- str u ct1il.Te; The next memb e r of the 8 eries ~o ,ld be a 1. Ann. 174,(1894),227. 2. D. ? .P. No 28753, Feb. 27, 1884. diaw 13 body containing three benzene residues and ce.n b e mad.e by nitrating s.ncl then re e. ucing the di-para: di-ni trocompound of the hydrocarbon, J-diphenyl benzene. This diamine J-l2 No-c_'>--ON J.l::i... t11e literature. is not descriged in This paper is a description of some preliminary work done towards obtaining this ami ne and the tetrazo body obtained by treating its hydrochloride with nitrous acid: -N 2. -Cl It would. be of interest to find vlhat tY]_:,e of clyes ( if e,ny) this heavy tetrazo-body would make by combination with conplex radicals. For example, would 1 mol combine with 2 mols sodium napthionate to form: N=N NH.g-50~Na tu.re Stebbens 1 obtained a tetrazo b ody of the s t rucNS N-0-C H. 0- ~ ;:" N and. found that he obtained the dr c11 ex-pee tea. addition product with s odium°'-napthol sulfonate, which differs from conga red in that it will not dye cotton without a mordant: N=r..J-0 CH,.--0-N=Ns rl oH LJso.,Noi OH so3 Noi • The effect of changing the -CR2- radical to 1. Jr. Incl. and Eng. Chem. 10,445. .l.":t -C5R 4 - v.r ill be the main int er es t o f t hi s vi ork . The n atural st s,rting point for this ec experiments would. be t he hydroc a rbon c18H14 , p-diphenyl benzene. This hydrocarbon has been obtai ned in small amounts as one of the products formed when benzene 1 , ana_ mixtures of benzene and toluene 2 , ar~passed through hot tubes. It is also formed by the action of ethyl iodide on potassium benzene§, by :th e action of smdium on mmnobrom- benzene 4 , and on a mixt u,re of para-dibrombenzene and monobrom benzene5, and when diazobenzene chloride reacts with diphenyl in the presence of anhydrous aluminym chloria_e6. The yields obtained by means of all these syntheses "Ere very s mall, howev er, so it was t hought best to e mploy lidirect methods for o~taining the hydrocarbon. The met hods proposed necessi tatecl t he use of para-amino-diphenyl which c an best be obtained by one of the following nethods. The fthrst is t h e diazo reaction of R. Hirsch 7_ in which he diazotized C5H 51TR2, convert~d the diazo compound into diazoamino benzene, e.nd heate d the latter with a large excess of aniline. He distilled off t he aniline and a f ter neutre.lizing, p recipitat ed_ t he par a-amino- diIJ henyl as its sulfate. The aut hor tried t hi s re action t hr ee times c are f ully and got only a very s mall yield., so 1. Schul t z, Ber. 6, 415. 2 •. Corn.elley, J. Chem. Soc. 37, 912 3. Abeljanz, Ber. }:} 9 , 11. 4~ Weiler, Ber. 29. 117. 5. Riese, Ann. Chem. Phar. 164, 161.(Compare Chattuway and Evans, J . Chem. Soc., 69, 981) 6. hlohlan and Berger, 3er.26, 1998. 7~ Ber. 25Tl9?3. 15 small that the method was of no value in obtaining a workable amount of para-amino-diphenyl. The second method consists of three steps and can be graphically shown thus: NO. 0-0 C)-C>N,O'z Diphenyl was mdde as descri@ed by Fisher1 by pas s ing benzene vapours thry a red hot iron tube. The nitration by the method of liflbner 2 gave a good yield and easy separation of ortho : and para products. 1.l:he para body is precipitated by add.i tion of a small amount of water and is obtained pure after o~e crystallization from alcohol. The reduction was easily accomplished in glacial acetic acid with z in:C, dust. The amine distills over 'td th steam, but at a very slow r e te, and is obt ained fairly pure • .A long tb1e is required and a large volume of distillate is obtained, but as the product is very slightly soluble in co.4,d water, the method is well ·worth the e:xpendi ture of time involved. For preparing d.iphenylbenzene from the s.minodi:phenyl three methods were considered.. One would have consisted in d.iazotizing the para.-arnino-d,ipp.en171l. and.~nE, 6 treating vii th a. large excess of aniline. The diazo-amino compound formed would. be changed to omino diphenyl benxene 1. Anleitung sur Darst cllung orgDnisher l'repartl.te, J3raunschweig, 1908, F.64• 2. Ber• 8, 8711. 16 by the application of heat, as in the method of Rirschl. This ro mpound could be diazotized and the resulting diazobody reduced to the hydrocarbon. :But as the Rirbh condensation was not a success in the preparation of para-arninodiphenyl, the method was discarded• A second method ·would have consisted in treating dry diazo-diphenyl chloride with benzene in presence of aluminpm chloride yielding the hydrocarbon directly. The thtrd would be to diazotize para-amino-diphenyl in aqueous solution and treat with an . \, excess of phenol according to the method of Hirsch 2 for obtaining p-hydroxy-diphenyl. This should give hydroxypara-diphenylbenzene, which when distilled with zint dust 31ould yield the desired hydrocarbon. The steps involved are as follows : Method lJo. 1,. OON=N-NHQ Q-Q-ONzCI 1. lac. cit. 2~ 3er. 23,3705. >- HC/ + Q-0-QNH~ HNO,, 0-0-0 17 . 0-0.::._NH~ HcL > Me tho d No. 3 . o--o-N~z He.I ► Q O N ! - 1 3 C I HNCe.;., O Q N a . C l C,H,;-Ot\ O-ON-=N-0-0 oH J,eat,.. ZH . . dust The hydrocarbon, para-dipheny;-benzene give s 1 ~hen brominated , di-pa ra-di-b rom-diphenyl - t onzene . _ Jonsequentli when nitrated it woul d be expe c ted to give di-para-ainitro-diphenyl-benzene, wh ic h on reductions should give t he des ire d ~iamino -di phenyl- be n zene. CJ-0--0 HN<h~ N~-0-0-0-tJ~--!:!. HzN-0-0-0--1 \.z. U. Ol gja ti, Ber . 18 EXPERIMENTAL !reparation of diphenyl. j3repared di phenyl by passing benzene inapours through a heated i:.r-on pipe filled. loosly with pumice placed in a combustion furnace and heated. to a high reel heat as described by Emil Fisher. The apparatus was fitted with a condenser to return the C5H 6 to the boiling flask and so dl!lmplete the circuit. Time was tho~ht to be a factor in the yield of dipuenyl so the process was arranged as nearly automatic as possible, requiring attention only in case of possible accident and fire. But this was reduced to a minimum by using an electric heater to boil the C6H6 ana_ partially surrounding the fu:nnace with asbestos boards. Wm the first experiment 350 cc. c H was put 6 6 into the fl::,.sk and the process kept up for 14 hours. The C5R5 was distilled off. The boiling point went up rapidly to 240 , a fraction was coliected between 240 and geve by recrystallization and 270 from alcohol 73.5 grams of pure diphenyl of m.p. 70.5 . A 47.6% yield of diphenyl was obtained calculated from the loss in wei&ht, which was ass:umed to be benzene. Smith and Lewcock1 conducted smme experiments on the production of di:pjienyl b~r passing benxene "tapour thru tubes of different sizes using d.ifferent catalytic a.gents. They conc·lud.e that c .~rson does not ca.talize 1. JJ Chem. Soc. 101, 1453. 19 the ac tion an d that t he c &,rbon after some time ca.uses the action to stop. (I.10 check t h is the apparatus was not changed and 200 cc. benzene passed thr.~ ag ,.dn for· 2 hours, giving a yield of' 5.5 gr ams. This is 2.7 grams p er hour as c ornpared with 5. 2 grams per hour in the previous experiment. There is a loss in eff ici ency with time. :Prepara tion of para-am j_no-diphenyl b y the methoa. of Hirsch. 1 50 grams (1 mol) aniline d-n :~i. 2.5 mols hydrochloric acid is diazotizea. with a solution of 39 grams sodium nitrite in 100 cc. water followed by addition of 950 grams c6H5NR2 and thoro she.king. The aniline layer is serJars,ted ana. dried wit h c alcium c hloride. The mixture is heated to 150 in an oil bath uhtil nitro gen ceases to be evolved, the temperature gradually increqsed to l~O C6H5:rm 2 distilled. off up to 200 and exdess . Distillation is stopped, the basic mixture cooled, heated with ten times its volume of water and made acid. with hydrochloric acid. At this point the solution tu.ms a deep red, due to formation of amido-azp-benzene hydrochlori de. :By careful neutralization the reel color dissai:)pesrs and by careful addition of sodium hydroxide the gr e ater part of t h e dis s olved a.mido-a.zo benzene sep arates, anc1 can 1) e f'il t ered off. The solution is 1~ Ber. 25, 1973. 20 treated with sodium sulfate to bring down t;he amino body as the sulfate. This experiment was tried three times and in each case the yield was very poor and only a very small yield wf i mpure product was obtained. In the first case the calcium chlorid.e used for drying combined with the aniline causing a loss of aniline and the dissolved. product. Anhydrous sodiu.m sulfate was used in the next t vrn expe:i:±Ernr:~~:;:;.. :m:.ents. The ;srield'. of the precipitated sulfate wa.s very small due to inability to get the proper concentratj_on of acid. Preparation of :para-nitro-diphenyl from diphenyl. Dissolved 45 grams diphenyl in 180 grams of glacial acetic acid and slowly added a solution of 144 grams fuming nitric acid in 144 grams glacial acetic acid. Heatea. on wat er bath for an hour. Cooled and added 90 cc. water which brings down the para compotmd almost completely. Ilft a larger amount of water is added, about equal in volume to that of acid, the impure ortho-body separates as an oil. The para-nitro-di phenyl crystalizes from alcohol in long, hard, yellow needles of m.p. 114. Yield of para body is 30%. Pre;earation of rjara-amino-diphenyl by reduction of para-nitro-diphen_;yl. Dissolved 3 grams c12H9N02 in 30 cc. glacial 21 acetic acid and added slowly 6 grams of zintt dust. This is lOO!fa excess. Heatea. between each a.ddi tion to boiling point of acetio acid under a reflux condenser. Steam distilled after malcing alkaline. Upon cooling lustrous flaky drystals of the amine came down. The an,ino body is very slowly volatile with steam and it takes a long time and a large volume of distillate to bring over all the amine. Yield was not determined but was about 50%. SUM1'LARY Prepared diphenyl by passing benzene vapours thru a hot iron tube. Attempts to prepare ps.ra-a"Ilino-diphenyl by diaz9 reaction of Hirsch were not successful in obtaining a workable amount of the amino fiody. Nitration of diphenyl gave a fair yield of pure para-ni tro-di :Jhenyl. Reduction of para-nitro-diphenyl with zinc in glacial acetic acid gave para-a~ino-di!J,enyl. Completion of the work was prevented by the calling of the author to the colors.