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Lakra 1926 3424713.Pdf Nitration Produota of Phenolic Eatera by Hans R •. La.kra B. So.• Pa.njab Un1ve;ra1ty, 1923. Submitt,ad to the Deptu:1tment of Chemistry and the f aoµlty or the Graduate Schooi or the University of Kansas in partial fulfillment of the requirements for the degree or Master or Arts. Approved by May 1926. I~~ Chairman o.f Department. ·I wish to express my gratitude to Drif R. Q. B:rewater, under whose 'd.lt'ection thia · work · was done 1 for the moat helpful auggeat1ons and all the cooper..... a:tion, Hana Laltra. page INT RODUC'X run l 5 ~, 4, DlN!ThUPHENOL ~~---~---------~-~----~-·---- 5 ETHYL J?liENYL CARBONA'l'JJ.: __ ... ______ ..,. .......... _._~ ...,.. ..... _"':".,.. ........... _ 5 ORTH.OJ NlTRU l~~r.rft{L l'lfl:&NYL C;WrJ3QN ..~\.'£E --"!"-~ .... --~-.-~ ... - 9 all1'£.ti.¥.J... J.>£1.)~N.l.u Lf.:Ui.Ovi~.:-.. t~ ..:. .....: _____ ,... .... _.-..;. __ ...,,...________ ll u. 12 PHENYL U.l{J'\.W~'rl~ ..., __________ .,. __________ .... _,..._""-""'·---- 15 £ .N.1. 1fRU l:i.HEl.J::lL vXAL.A'l.'li!. ~-------.---- .... -,.... ....... _. ........ ______ 16 "). 7 18 20 ~--~-~-~-~-~~--~--- 21 24 P • lUTRO PHEMYL PRO?IONA'.r!~ ------~ ....... ...,-... -~--..-- .... 24 PHENIL Bl~HZOA'.CE ---~---------..-...-------------·--- 26 p • NITHO PHI;~NYL BBNZOATE ___ ....,_ .... _.,._,;oo---~ .... ·-~"":'-• 27 29 BIBLIOGRAPHY -------------·----------------------- 30 1 NITRATION PRODUCTS OF PHENOLIC ESTERS. Introduction: The ma1n object ot undertaking t..h1a piece of work was to 1nvest1ga.te the position at which nitro groups enter th~ benzene r1ng in phenolio esters. At the same time we hoped to find some ,methods of linking such nltro groups to the phenolic esters by direct nitra- ., tion rather than by the prepa.ra.t1on or the same compound by indirect methods. Moat of.the products obtained by nitrating such eaters have already been synthesised by indirect methods during the last few years. The nitration or the dltf erent eaters proved to be a matter of cons1d·erable interest beoause or the var•iety or methods involved and the.\ part ,played by the temperature in ~ontroll1ng the number.of nitro groups entering into comb1na.t1on. Mitric a.c1d itself reacts 1n a number of ways,.: the following are the few more important ones: {l) Action of dilute nitric acid on some organic compounds: Dilute nitric acid,. which very often acts as a.n oxidising agent, can 'be used for introducing the nitro group, N02 1 under certain conditions. For example. phenol can be converted into n1t~o phenol by three per- cent nitric acid, while four percent nitric a.old converts 2 methyl and ethyl acetan1lld.e into the co~reeponding di.:.. nitro derivatives. The n1tro group can also be aubati- tuted 1n the side cha.in by heating toluene with dilute nitric a.c1d_under pressure. A similar reaction takes place with other alkyl derivatives of benzene. The reaction, however, is not generally ;·employ~Q., as it 1e necessary to boil the mixturer for several hours. Sodium ·<. and pota.saiumnitratee 1n dilute sulfuric acid solution of nitric acid in glacial acetic acid; ether, and acetic anhydride are also used. (2) Action of concentrated nitric acid on aromatic compounds: •n.C Concentrated nitric acid up to~hundred percent 1a required f'or nitrating many compounds which are not oxidised by this treat~~nt. For y;hls reason it ia not used in the aliphatic series nor with: compounds conta.ing ·an easily ox1disable e1de. :ch~in.· ..Th~. reaction is represented by the equation: In this reaction the question of ·temperature ls one_ of importance~ In general a.a the ttempera.ture 1s ra1sed, I the tendency to form q1-n1tro, tri-nitro and pc>lynitro derivatives 1a much increased. 3 {3) Action or a mixture of concentrated nitric acid and concentrated aulfur1c ac1d (mixed acid) on a£omat1c compounds: Thia reaction is the moat ~mportant for nitration and ia represented, ·a.a before, by the equation The theoretical quantity or nitric acid 1e added to a large excess of concentrated sulfuric acid, and the . mixed acid added to the compound to be nitrated. Or the compound may be dissolved in excess of concentrated sulfuric acid, and the theoretical quantity of strong nitric acid then added., The excess ot sulfuric acid ia added to absorb the 11ater formed 1n the reaction, ·which would reduce the concentration of nitric acid ultimately to a polnt where no nitration will take place~ Aa the reaction proceeds, the formation of water dilutes the sulfuric acid to such an extent that reaction finally ceases. The conaentra.t1on of sulfuric acid muat,there- fore, be ma.1nta1ned above a certain minimum~ Influence of ~empe~ature: The proportion of different isomers formed in nitration ia influenced by temperature• The table ahovte the alteration in proportion when nitration ia carried. out at different temperatures on toluene: 4 Temperature Ort ho Meta. Para 0 -30 55.6% 2.7 1o 41.7 'lo ~o 56 % 3.1 % 40.9 % 0 3 56.9 % 3.2 % 39.9 % I Rules of nitration: The position taken by the nitro group entering the nucleus depends· upon the ·group or groups already present 1n t~e nucleus. When the subata.nce contains an O H, NH2• ci, ·or CH3 group. nitration gives a mixture of ortho and para n1tro compounds. When a SOji, COOH, ON, CHO, or M02 group 1a presen~.• nitration gives ohlef~y the meta compound. The 1a·o1ation of n1tro compounds: There ia usually little diff 1culty in the isolation of nitro compounds .. Solid nitre products can be separated by crystalliaat;1on, and 1n some cases, by dlluting the mixed acid, or simply pouring into water. In cases, \Vhere both of these methods prove unauocessful, extraction with ether, after dilution, may be attempted, In liquid nitro compounds, advantage is ts.ken of thelr specific gravity ln the aepa.ra.tion. 5 EXPERIMENTAL. Preparation of' Phenyl' Acetate. 9. 4 grams o,t phenol. 8~00 grams of Acetyl Chloride. The a.cetyl chloride was slowly added to :the phenol in a.n erlynmeyer flask. The mixture was allowed to· stand for three to four hours, after which it.was wash- ed with dilute sodium hydroxide solution and then w1tb. water.- It was finally dried over calcium chloride and distilled. Yield tan grams. C> B. P. 193 C6H50H + CH3COCl ~ . OH3COOO()H5 + HCl NitJ;'ation ot Phenyl Acetate .• t> 13•6 grams of phenyl aoeta~e were dissolved in 5lae1al acetic a.aid, The mixture was stirred mechani- cally e-nd ten grams of fuming nitric acid were ·added drop by drop, The temperature was controlled between 50 and 60 degrees. The stirring was continued f'or several ·hours, till, a drop, when poured into water, sold1f1ed. The nitrated product was, then, poured into water. The aolld thus obtained. was separated on a. f 1lter paper. It was dried ~n ~ porous plate and reorystalliaed trom alcohol. Yield 14 grams, 6 M!! P. 113° - 114° ~No2 I ..... + CHf OOH + H20 ~02 0 • S1noe ~he produot obtained melted at 113 • 114 it was suspected that 1t might be para-n1tropheno.l I) Q . ' ' ( M., .P. 113 ..... ll4 ) , and the acetyl group might have . ' ,, been hydrolysed during thELn1trat1on.• On mixing the product with pa.ra."."'nitropheno1 1 the melting point was \) observed to be 83 ·~ Bence it was c:onf 1rmed that it was not para-nitrophenol. The p;roduot gave test ror · nitrogen. It was further hydrolyaed1 and the hydro- ' . 6 lysed product also melted at ll3 • 1140 , showing thereby that hydrolysis did not effect it 1n any ' ' ; G Q way, Since 2, 4, Di~nltrophenol melts at 113 - 114 , its a.na.lys1a was run for nitrogen. The nitrogen ·contents were found to be 15.212 percent, which checked very close to the theoretical amount of nitrogen 15.217 percent in 2, 4, Di-n1trophenol~ Hence, it was confirmed; that phenyl acetate during n1trat1onwa.s hydrolysed to acetic acid and phenol, the latter being' nitrated: to 2 1 i~, D1-n1trophenol .,,.. • T~ <oot·a·ih a still oonfirma.iory test, an attempt was made to prepare 2, 4, D1-n1trophenol, in order to obtain a. mixed melting point.• 7 2 1 4, D1-n1trophenol, "' As stated before, an attempt was made to prepare 2 1 4 1 Di-nitrophenol by the following process: 200 grams of phenol w:ere dissolved in 400 grams () of concentrated sulfuric acid at 110°- 115, with oonti- 0 nuous stirring. The product was, then, heated at 130 ~ 0 140 , :ror five hours. It wa.a, then, cooled to a temper- • 0 . ' a.ture'.between 40 and 50, and 1375 grams of concentrated nitr1c acid were added very slowly with constant stirr- ing. The product was allowed to stand for twenty four hours, after w.hioh it was heated for three days on vmter bath. '.Che solid product wa.a filtered while oool, and the precipitate wae extracted with water. Yield 100 grams. • M. P. 118 Oonclus1ons; The yield was very sa.t1ataotory - 100 grams,, but 1t was .round to be p1cr1o acid, which was. confirmed by a. ml,xed melting point determination • Notwithstanding the fa.ct 1 that every possible precaution was t·aken to control the temperature• three nit.ro groupa were in- troduced instead of two. 8 ···.\ -· .. Determination of nitrogen. 1n the product.obtained by the n1trati1on of phenyl a~etate. i_ o.1865 gra.ma or the aample'.gave. 25.47 cc. of nitrogen. (J at 22.2 and 74.4 cm. pressure. · N1t·rogen 14~ 2J1 ]b, 2.. 0.1960 grams of the sampl~ gave 26.- 75 cc, of' 0 nitrogen at 22.4 and 74,4 cm, pressure.
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