\ 
 
 
 
 
 
 
 
 
ARTIFICIAL MUSKS: 
 
 THE STABILITY OF THE ISOPROPYL 
 GROUP IN CYMENEAND ITS 
 DERIVATIVES 
 
 I1Y 
 
 MORIS HOWARD JOFFE 
 
 THESIS 
 
 FOR THE 
 
 DEGREE OF BACHELOR OF SCIENCE 
 
 CHEMICAL ENGINEERING 
 
 COLLEGE OF LIBERAL ARTS AND SCIENCES 
 
 UNIVERSITY OF ILLINOIS 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
UNIVERSITY OF ILLINOIS 
 
 Ua,j c**x 
 
 192 
 
 THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION BY 
 
 Yorie Hcv.^rd Jot:; 
 
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 J^TTj*jTJ ,J J . Jk. - _ W ... - » 
 
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 • rou±. in Cy.osne anl its Derivative^ 
 
 IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE 
 
 DEGREE OF 
 
 Bachelor of 
 
 . Vy *- . U- 
 
 Chemical Engineering 
 
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 C_c^^vJL_ JL l 
 
 Instructor in Charge 
 
 Approv 
 
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 HEAD OF DEPARTMENT OF 
 
Digitized by the Internet Archive 
 in 2015 
 
 https://archive.org/details/artificialmuskssOOjoff 
 
ACK1T 0 vVItSDGrBLIEIff T 
 
 In writing this thesis the author wishes to 
 acknowledge his indebtedness to Doctor Carl S. Marvel, 
 under whose supervision this work was done, for his 
 numerous, invaluable suggestions, for his interest in the 
 work and for his ready willingness to help. 
 
TABLE OE CONTENTS 
 
 Page 
 
 I. Introduction and Historical -- — ■ 1 
 
 II* Theoretical — 3 
 
 III. Experimental 10 
 
 IV. Summary 17 
 
INTRODUCTION AND HISTORICAL 
 
 Most of the expensive perfumes are unstable; the fragrance 
 will not last, ^uite accidentlly it was found that a small 
 portion of ’mush' will prevent decomposition and will even increase 
 the strength of the fragrance. LIusks, then, find their chief use 
 in the perfume industries. Natural products which are obtained 
 with difficulty and are expensive always form an incentive towards 
 the preparation of synthetic or artifical products. 
 
 When one speaks of a syntptie or artifical product one 
 naturally surmises that the synthesized compound has the same 
 composition as the natural product. With artifical musks, however, 
 this does not apply. Natural musks have been studied, yet 
 little is known as to their structure. It has been determined 
 that the active principle is of a ketonic structure and that it 
 contains no nitrogen. The artifical musk is a nitro-derivative 
 of the benzene series and resembles the natural product in odor 
 only. 
 
 Among the foremost of investigators in synthesizing artifical 
 musks was Albert Bauer. Together with Thurgan he synthesized 
 
 tri-ni tro-pseudo butyl toluene, tri-nitro pseudo butyl meta 
 
 1 2 
 
 xylene , methyl ether of tri-nitro oxy pseudo butyl methyl benzene, 
 
 dinitro tertiary butyl xylyl methyl ketone, methyl ketone of tri- 
 
 1. B. 24, 2832-2843 
 
 2. B. 27, 1614-1619 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 2 - 
 
 < 7 . 
 
 nitro pseudo butyl toluene and di-nitro tertiary bu.tyl xylyl 
 4 
 
 aldehyde . All of these compound smell strongly of musk. Kis 
 work was followed by many others and numerous patents, both in 
 Germany and France were issued for the preparation of artifical 
 musks . 
 
 The object of this research is to prepare a product having 
 a strong odor of musk, using cymene as the base; cymene being 
 chosen because of its comparative cheapness. 
 
 3. B. 31, 1344-1349 
 
 4. B. 32, 3647-3648 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
THEORETICAL 
 
 Following along the line of work done by Baur and Thurgan, 
 
 the methyl ketone of cymene was prepared"* - . In the first runs 
 
 the yield was very poor but by using a mercury seal stirrer and 
 
 a three-necked flask, which made possible the introduction of the 
 
 acetyl chloride slowly, the product was obtained with a yield 
 
 of 62$. In large runs extreme care had to be exercised because 
 
 of the large amount of carbon bisulphide used as a solvent. This 
 
 ketone was then nitrated. For nitration purposes, in synthesizing 
 
 ketone musks, Baur used 100 $ nitric acid. Although 100 $ acid, 
 
 as a nitrating agent is not used now.it was thought advisable to 
 
 make a run using Baur's method. Being unable to obtain the acid 
 
 its preparation was tried, but the attempt proved unsuccessful. 
 
 The problem was referred to the research department of the 
 
 General Chemical Company, but was reported as a failure. This 
 
 means of nitration had to be given up and instead, 7 $ fuming 
 
 sulphuric acid followed by fuming nitric acid was used. 
 
 of 
 
 The results obtained by nitration 'acetocymene were very 
 
 A 
 
 discouraging. All of Baur's compounds possessed a definite cry- 
 stalline form. Acetocymene, however, on nitration came down as 
 a gummy mass, which could not be crystallized from alcohol, petrol- 
 
 et/m 
 
 ether, benzene, ethyl acetate or a mixture of ethyl acetate and 
 benzene. The mass was set aside for six weeks and then a crystal- 
 line compound isolated from carbon tetrachloride. It was thought 
 that this compound was a mono or dinitro derivative of acetocymene, 
 
 1. Jour, fxir pr. ch. 42, 508 
 

 
 
 
 
 
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— i3— 
 
 but tests showed that the compound was an acid, giving a definite 
 neutral equivalent. This fact seemed so out of the ordinary that 
 the preparation of further artifical musks was given up and the 
 determination of the structure of this compound undertaken. 
 
 The nitration of acetocymene was repeated to obtain the 
 yield of crystalline product. Attempts to isolate a solid from 
 carbon tetrachloride immediately after nitrstion failed. It seemed 
 that some "aging" is required before a separation can be made. 
 
 In 1920 A If than ^ , a German chemist* studied the nitration 
 products of cymene and toluene. He found that cymene on nitration 
 gave 2,6 din itro cymene and also 2,4 dinitro toluene. In the 
 latter case the iso-propyl group is first oxidized to the acid 
 and then the carboxyl group is replaced by a nitro group. He 
 also found that p-acetfi) toluene upon nitration gave 2,6 dinitro- 
 p toluic acid. 
 
 The product which was obtained by nitrating acetocymene 
 dissolves in sodium hydroxide and gives a neutral equivalent. 
 
 From previous work on cymene the following possibilities for its 
 structure suggest themself. 
 
 I 
 
 C-OH QN 
 
 hC^ch 3 
 J Z68 
 
 B. 53B, 178 
 

 
 
 
 
 
 
 , ' « * Jig i 
 
 
 
 
 , 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-4- 
 
 All three possibilities contain two nitro groups. The analysis 
 for nitrogen clearly verifies this assumption. The neutral 
 equivalent of 263, that was obtained eliminates formula I. The 
 analysis for C eliminates formula II; formula III then remains. 
 The nitrated product was oxidized using potassium permanganate in 
 alkaline solution as the oxidizing agent. A white ciystalline 
 product melting sharply was obtained. A neutral equivalent was 
 taken which showed the presence of two carboxyl groups. If 
 formula III were correct the oxidation product should be 
 
 From previous work it has been shown that the isopropyl group is 
 unstable and will be oxidized first. An analysis of the oxidation 
 product showed the presence of only one nitro group and the 
 neutral equivalent and the analysis for carbon did not check 
 with the above formula. The only other possibility is that one 
 nitro group has entered the isopropyl group, which on oxidation 
 was removed. 
 
 The following structure was assigned to the crystalline product 
 isolated from the nitration of acetocymene. All analysis verify 
 
 CHj 
 
 N OH 
 
 Hf^CH d 
 

 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
— 5— 
 
 this assumption. 
 
 The stability of the isopropyl group in all of the previous 
 work was not of the same degree. The author set out, therefore, 
 to determine what properties or conditions were necessary to 
 make the isopropyl group in cymene or its derivatives stable 
 towards the action of the nitrating agent, sulphuric acid-nitric 
 acid. 
 
 1 
 
 P- cymene treated with chlorine forms monochloro- cymene. 
 
 This on nitration gives 2- chloro-dinitro cymene. The yield was 
 
 high, although a small amount of oxidation product was obtained, 
 b 2 
 
 Again, when tymol was nitrated , trinitro- thymol was not obtained. 
 Instead, the isopropyl group was removed forming trinitro-m- 
 cresol. Mr- Zellhoefer, of our laboratories, nitrated the 
 methyl ether of "thymol and obtained the methyl ether of tri-nitro- 
 a-cresol . 
 
 These works as well as the work on cymene led to the belief 
 that the group meta to the isopropyl group had some definite 
 relation to the stability of that group. So many ideas have 
 been set forth that nothing definite has as yet been determined 
 along this line. With these points in view the second* step in 
 
 V 
 
 this research was begun. 
 
 Since the -COOH^ group in acetocymene on nitration was 
 oxidized to the carboxyl group the first step was to prepare 
 o- me thy 1-m- isopropyl benzoic acid from acetocymene. A strong 
 
 1. J.Ind. and 3ng. Chem. 11, 1130-1133 
 
 2. Chem. News 47, 115 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 I 
 
 
 
 
 
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- 6 - 
 
 strong oxidiz&ng agent could not be used because of the unstabil ■ 
 ity of the isopropyl group. Directions are given in Noyes 
 laboratory Manual for the oxidation of berjalacetone to cinn- 
 amic acid by using sodium hypochlorite as the oxidizing agent. 
 
 By following these general directions with the exception that a 
 more concentrated hypochlori te solution was used it was possible 
 to oxidize acetocyrnene to o- me thy 1-m- isopropyl benzoic acid 
 in yields exceeding 75 $• This acid has previously been 
 prepared’ 3 ' by heating tricarvaCrol phosphate with potassium 
 cyanide and then hydrolyzing the product. This reaction is 
 
 acc omp a n /ed 
 
 ^by the formation of many impurities which make it much more 
 complicated than the method used above. 
 
 The acid thus obtained was then nitrated under the same 
 conditions that acetocyrnene was nitrated, A pale yellow 
 compound was obtained which upon recrystallization from 50 $ 
 alcohol came down in very fine needles, clustering to form 
 plates. A mixed melting point with the nitration product of 
 actocymene gave a melting point which was the same as that of 
 the original compound. There is no doubt that the compound 
 obtained from the nitration of acetocyrnene and from the nitra- 
 tion of o-methyl-m-isopropyl benzoic acid are the same. There 
 is, however, a marked difference in the yields of these products, 
 The first was obtained with difficulty with a yield of 15$, 
 while the second was obtained with a yield of 9 £$. Here we 
 have evidence, surely, of a stabilizing action. 
 
 1. B. 18, 1714 
 

 
 
 
 
 
 
 
 
 
 
 
 
 J 
 
 _ 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
-7- 
 
 It seems highly probable that the carboxyl group meta 
 to the isopropyl group stabilises that group towards the action 
 of the nitrating agent. 
 
 <P 
 
 To further verify the assumption that the - C -Q 
 stabilizes the isopropyl group the methyl ester of o-methyl- meta- 
 isopropyl benzoic acid was nitrated. The o-me thy 1-m- isopropyl 
 benzoyl chloride was first prepared and this on treatment with 
 
 absolute methyl alcohol gave the ester. 
 
 a 
 
 The ester, like acetocymene, is* high boiling liquid; the 
 characteristic properties of these two compounds are closely 
 related. Yet, aceto-cymene on nitration forms a gummy mass 
 from v/hich a definite crystalline compound is obtained with 
 difficulty, while the ester when nitrated under exactly the same 
 conditions, reacts very smoothly forming a well crystallized 
 product. The difference in behavior of these two compounds can 
 
 fi 
 
 be explained by the stabilizing action which the - C -0 group 
 meta to the isopropyl group has towards that group. 
 
 Alfthan^ in his article states that 2,3,6 trinitrocymene 
 
 has been obtained by nitrating cymene. R. Ritiig 2 obtained a 
 
 0 
 
 ’trinitrocymene’ v/hich melts at 119 . Zaloziecki also 
 isolated a ’trinitrocymene' melting at 126°, while Landolf^ 
 obtained a compound which he also calls trinitrocymene melting 
 at 183.5°- 184. 5°. It is the belief of the author that cymene 
 
 3. B. 27, 2065 
 
 4. B. 6, 938 (1873) 
 
 1. B. 53B, 180 
 
 2. A. 145, 142(1863) 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 , 
 
 
 
 
 
 
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 ' 
 
 
 
 . 
 
 
- 8 - 
 
 on nitration forms dinljtrocymene and that on farther nitration 
 the third nitro group enters the side chain forming a compound 
 with the following structure. 
 
 The 2,6 dinitrocymene was prepared and then nitrated. The 
 reaction did not proceed smoothly. 
 
 Inc connection with the preparation of acetocymene several 
 
 runs were made to determine whether aluminum chloride in the 
 ffriedel and Craft’s reaction adds on as A1C1,, or as AlgCl . If 
 
 it adds on as AlgCl. two mols would have to he used to obtain 
 $he product. Two runs using first one mol and then two mols of 
 aluminum chloride gave yields of 41 /j and 41.5;b • Without a 
 question only one mol is necessary in the above reaction. 
 
 Butyl derivatives of the benzene series, especially toluene 
 and xylene, when nitrated form very good artifice! musks. The 
 introduction of a tertiaiy bujyl group into cymene by the Friedel 
 and Craft’s reaction using aluminum chloride was tried but very 
 poor yields were obtained. In a recent review on artifical 
 musks'*' the authors state that to intoduce the butyl group into 
 the benzene ring ferric chloride should be used instead of 
 
 1. Chemie and Ind. 6, 719 
 
 ch 3 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 9 - 
 
 aluminura chloride. The failure to prepare tertiary butyl cymene 
 is then accounted for. 
 
 Acetoraesitylene was prepared and this product nitrated 
 gave a compound with a musk odor. 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
EXPERIMENTAL 
 
 p-Cymol methyl ketone, acetocymene 
 
 To 480 gr. of cymene ( 10 mols) 2000 c.c. of carbon, 
 bisulphide was added. The mixture was kept in an ice bath. To 
 this 440 gr. of pulverised aluminum chloride was slowly added. 
 After the reaction ceased 280 gr. ( 10 mols) of acetyl chloride 
 was added drop by drop, the mixture being vigorously stirred 
 by means of a mechanical stirrer. The whole was allowed to 
 reflux for two to three hours until all the hydrochloric acid 
 evolved came over. The carbon bisulphide was then quickly 
 distilled and the residue poured over ice water to remove the 
 aluminum chloride. The dark brown oil was separated and ex- 
 tracted with ether. The ether solution was washed with water 
 and then dried over calcium chloride. The dry ether solution 
 was then distilled. A clear, yellow, sweet smelling oil 
 boiling at 256° - 260°, uncorrected, was obtained. Yield 
 392 gr., 62/o. 
 
 Nitration of Ace to cymene 
 
 To 20 gr. of acetocymene, kept at 0° 0., 66 gr. of Tp 
 
 fuming sulphuric acid was slowly added. The ketone slowly 
 
 changed its color until quite dark brown on addition of all 
 
 the acid. To this solution 34 gr. of fuming nitric acid ( sp. gr. 
 
 1.50) was added at the rate of 30 drops per minute, a mechanical 
 
 stirrer being used. After all of the acid was added the nitra- 
 tion was allowed to proceed for another two hours. 
 
, 
 
 
 
 
 : 
 
 ■ 
 
 
 
 
 
 
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 . 
 
 
 
 
 
 
 
 , 
 
 * 
 
 
 
 . 
 
 
 ; , 
 
 »■ 
 
 
 ’ 
 
 
 
 
- 11 - 
 
 A dark brown mss was obtained which was poured over ice water 
 and thorougly washed from all acids. The final product which 
 was light yellow r in color formed a gummy mass. After standing- 
 six weeks a crystalline compound was isolated from carbon tetra' 
 chloride. Yield 3 grams. 
 
 Analysis of Nitration Product 
 
 Subs. Q.1S86; 6.35 c.c. of 0.1187 IT. ITaOH required. 
 
 Subs. 0.E500, 0.4000; C0 g ;266.8 c.c., 428 c.c.; Temp. 26°, 
 
 23° 0.; Pressure: 741.7 mm., 734.2 mm. 
 
 Subs. 0.2090; N: 20.4 c.c.; Temp.: 24° C. ; 3ar. 741 mm. 
 
 Calc, for C i:L H 12 0 6 IT 2 : C, 49.2; IT: 10.42; N.E. 268 
 
 Pound: G: 49.23; 2 : 10.71; N.B. 263 
 
 n 49.51 
 
 M.P. 182.5 , 183.5°, 183°. 
 
 Oxidation of Nitrated Coumpound 
 
 1 gram of the nitrated product was dissolved in 10 c.c. of 
 10/a sodium bicarbonate solution. To this 5.5 gram of potassium 
 permanganate, dissolved in water containing 3 c.c of 10 fo sodium 
 hydroxide, was added. The mixture was allowed to refux for 
 twelve hours. At the end of this period the manganese dioxide 
 was filtered off and any impurities soluble in ether removed. 
 The residue was acidified with dilute sulphuric acid and the 
 product extracted with ether. The ether was distilled off and 
 the product recrystallized from hot water. It came down in 
 fine white needles melting at 199° - 200° q. 
 

 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 12 - 
 
 Analysis 
 
 Subs: 0.23275; 22.14 c.c. of 0.0909 N i£0H required. 
 
 Subs: 0.3014 gr. ; CO , 310 c.c.: Temp. 21. 8 U C. , Bar. 740.5im|. 
 Subs: 0.1932; N: 10.4 c.c.; Temp. 25° C. ; Bar. 746.8 mm. 
 
 Calc, for C g K„0 N: N.E. , 112.5; C: 48; N: 6.22 
 
 found 
 
 N.E. , 115.5; C: 48.27; N: 5.93 
 
 o-LIethyl-m- Isopropyl Benzoic Acid 
 
 To 450 gr. of chloride of lime 600 c.c. of water was added. 
 To this 550 gr. of sodium carbonate in 650 c.c. of water was 
 added. The mass was filtered and washed once. The filtrate was 
 added to 50 gr. of acetocymene and the whole refluxed for four 
 hours, keeping the temperature at 80° - 90° C. A mechanical 
 stirrer was used. At the end of the reaction, shown by the 
 disappearance of the oily layer, the mixture was cooled and the 
 uncombined acetocymene extracted with ether. The residue was 
 acidified with dilute sulphuric acid, the produce extracted with 
 ether and then recrystallized from 50 °/o alcohol. It came down in 
 white needles clustering into plates. M.P. 75° C. Yield 27.5 gr. 
 55$. 15 gr. of acetocymene was recovered, making an actual yield 
 
 of 78.5 $. 
 
 Nitration of o-me thy 1-m- isopropyl benzoic acid 
 
 To 5 gr. of the acid, kept at 0° G. 17 gr. of 7$ fuming 
 sulphuric acid was slowly added, which seems to dissolve the 
 
 product .forming a brown mixture. To this mixture 8 gr. of 
 fuming nitric acid (sp. gr. 1.50) was added drop by drop. On 
 

 • ■ ; , 
 
 
 
 
 
 
 to 
 
 
 
 
 
 
 
 
 
 
 
- 13- 
 
 add i tion of the nitric acid the mixture gradually chanXged to a 
 lemon yellow color* It was allowed to mitrate for one hour after 
 all of the nitric acid was added, and then poured over ice water 
 and thoroughly washed* Upon recrystallization from 50^ alcohol 
 it came down in fine white crystals melting at 182° G. A Tftixbd 
 melting point with the product isolated from the nitration of 
 acetocymene gave a melting point of 182° * ITo gummy mass was 
 formed. 
 
 o-Ifleizyl-m- isopropyl benzoyl chlorid e 
 
 To 5 gr* of o-methyl-m- isopropyl benzoic acid 6 gr* of 
 finely pulverized phosphorous pen tachlo ride was added* The 
 reaction began after shaking vigorously and heating slightly on 
 the steam bath* A dirty yellow liquid was formed which ^as distill- 
 ed under diminished pressure from an oil bath. The excess phos- 
 phorous pen ta chloride distilled over first and was removed* A 
 light greenish yellow, clear liquid having a sharp odor and boiling 
 
 o , V 
 
 at 153 (25 mm.) was obtained. 
 
 Yield 2.5 gr. , 45.4 fo 
 
 Analysis of Product 
 
 To 15 c.c. of absolute ethyl elcohol a definite amount of the 
 chloride was added. To this solution 1 gr. of sodium was added, 
 and the whole refluxed on the steam bath for a half hour. A 
 miliy white liquid was obtained. The alcohol was distilled off 
 and the residue diluted with 20 cc. of water containing 2 c.c. of 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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-14- 
 
 conc. HNO r . . The solution was titrated with standard silver nitrate 
 5 
 
 using ferrous sulfate as the indicator. 
 
 Subs: 7559, 42.3 c.c. of 0.0981 N AglTG- required. 
 
 Calc, for C__H__QC1: Cl: 19.29y6. Found Cl: 19*51/6 
 
 11 15 
 
 Methyl Ester of o-methyl-m- i sopropyl benz ol c acid 
 
 To 7 gr. of the acid chloride 10 c.c. of absolute methyl 
 alcohol was added, and the whole refluxed for eight hours. The 
 liquid obtained was distilled under diminished pressure using 
 an oil bath. A clear, colorless liquid having a very pleasant 
 odor and a boiling point of 132° (10 mm.) was obtained. 
 
 Yield 5.9 gr. 86.876. 
 
 Nitration of the methyl ester of O-methyl-m- isopropyl benzoic acid 
 To 5.9 gr. of the ester 19.7 gr. of 7 '76 fuming sulphuric 
 acid was slowly added, keeping the solution at 0°C and well 
 stirred. No change in the solution was noticed. To this 9.8 gr. 
 of fuming nitric acid ( sp.gr. 1.50) was ad' ed at the rate cf 30 
 droids a minute. The solution first became orange yellow then 
 light yellow and viscous as more acid wad added. After the 
 addition of the nitric acid the mixture was allowed to nitrate 
 for another hour. At the end of this period it was poured over 
 ice and thorougly washed until free from acids. It was recrystal- 
 lized from 50/6 alcohol coming down in clustering needles which 
 were v/hite when freshly formed, but which turned orange on 
 

 
 
 
 
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-15- 
 
 standing. M.P. 161°, but not definite. No sticky mass, as in 
 the nitration of acetocymene, was formed. 
 
 2,6 Dinitrocymene 
 
 To 25 gr. of p-cymene 100 gr. of sulfuric acid ( sp. gr. 1.84) 
 was slowly added. The solution was cooled by salt-ice mixture 
 and well stirred by a mechanical stirrer. On addition of the 
 acid the solution became yellow. To this 50 gr. of fuming nitric 
 acid ( sp. gr. 1.50) was added drop by drop. The solution became 
 dark brown. It was allowed to nitrate for two hours. At the 
 end of this period it was poured over ice water. It came 
 down as a sticky brownish mass which was extracted with ether 
 and thorougly w r ashed with v/ater until free from acids. To the 
 ether solution 50 c.c of 10$ sodium bicarbonate solution was added 
 Any acids that may have formed were thus removed. The ether 
 soluble portion was again washed and then dried over CaCig. The 
 ether was distilled off leaving a clear, rather viscous, reddish 
 liquid. Yield 25 gr. , 59.7$. 
 
 Analysis 
 
 Subs. 0.4148; 493.6 c.c. CGg; Temp. 30.2°; Bar. 741.3 
 Calc, for c i0 H 12°4 K 2 : G: 53 * 57 '^ Found: C: 53.51$ 
 
 Nitration of 2,6 Binitrocymene 
 
 To 10 gr. of dinitrocymene 33 gr. of 7 $ fuming sulfuric 
 
 acid was added. The solution first became light yellow but turned 
 to dark boown on addition of all of the acid. To this 17 gr. of 
 
 fuming nitric acid (sp. gr. 1.50) was added drop by drop. The 
 

 
 
 
 
 
 
 
 
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-16- 
 
 color gradually changed to yellow* After nitrating for an hour 
 the product was poured over ice water. It came down as a gummy 
 mass. A solid was isolated from carbon tetrachloride which 
 melted at approximately £10°. The yield was poor. 
 
 Ace tomes itylene 
 
 50 grams of mesitylene was dissolved in 200 c.c. of carbon 
 bisulphide, to which wa& added 125 gr. of freshly distilled 
 acetyl chloride. By using a three necked flask 50 gr. of 
 finely pulverized aluminum chloride was added just fast enough to 
 keep the reaction going. The mixture was mechanically stirred 
 and allowed to react for one hour. The carbon bisulphide was 
 then quickly distilled and the residue poured over ice water. 
 
 The oil was extracted with ether, washed, then dried over calcium 
 chloride and distilled. A light yellow, clear liquid boiling at 
 235° -237° (uncorrected) was obtained. Yield 48 grams., 72;a . 
 
 The reaction should not be allowed to proceed for more than one 
 hour, and the aluminum chloride must be added slowly to obtain a 
 product with yields over 70 'jo. 
 
 Hitration of Ace tomes itylene 
 
 To 10 gr. of aeetomesitylene 34 gr. of 7$ fuming sulfuric 
 acid was added. To this solution 17 gr. of fuming nitric acid 
 (sp. gr. 1.50) was added drop by drop. After nitrating for an 
 
 hour the product was poured over ice water and thorough tly washed. 
 It was extracted w ith ether and the ether then evaporated. A 
 
 light brown solid melting at 193° with darkening v/as obtained. 
 

 
 
 
 
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-17- 
 
 suiUAKV 
 
 I* Acetocymene was prepared and then nitrated using fuming 
 sulfuric acid and fuming nitric acid( sp. gr. 1.50) as th^i trating 
 agent. A crystalline compound was isolated with difficulty. 
 
 II. The structure of this compound was determined. The -COOK^ 
 group, was oxidized to the carboxyl group, one nitro group 
 entered the side chain in the isopropyl group and one nitro 
 group entered the ring. 
 
 III. o-Me thy 1-in- isopropyl benzoic acid was prepared and then 
 nitrated under the same condition as acetocymene. The nitration 
 products of both were the same, the yield in the latter, however, 
 was much greater. 
 
 IV. The methyl ester of 0-methyl-m- isopropyl benzoic acid was 
 nitrated as above and a solid compound obtained without the 
 formation of side products. 
 
 v. Some evidence was collected which indicated that the - 0 - 0 
 group, meta to the isopropyl group, stabilizes that group towards 
 the action of the nitrating agent sulfuric acid--nitric acid. 
 
 VI. Ace tomes itylene was prepared and then nitrated. A compound 
 smelling of mush was obtained.