THE ASYMMETRY OF THE ALIPHATIC 
 DIAZO ESTERS 
 
 BY 
 
 HOWARD MARION CHILES 
 
 B.S. University of Illinois, 1917 
 M.S. University of Illinois, 1920 
 
 THESIS 
 
 SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS 
 FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN CHEMISTRY 
 IN THE GRADUATE SCHOOL OF THE UNIVERSITY 
 OF ILLINOIS. 1922 
 
 URBANA, ILLINOIS 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
&.2L. 
 
 Q-Mj 
 

 
 Digitized by the Internet Archive 
 in 2015 
 
 
 
 https://archive.org/details/asymmetryofaliphOOchil 
 
ACKNOWLEDGMENT 
 
 The writer wishes to express his thanks 
 to Professor W. A. Noyes for his assistance 
 and interest in this investigation, which was 
 proposed by him and carried out under his dir- 
 ection. He also wishes to thank Dr. C. S. 
 Marvel for mary helpful suggestions which he 
 has given as well as for a part of the mater- 
 ials used which were prepared by him. 
 
I INTRODUCTION 
 
 1 
 
 A little more than a year ago Levene and Mikeska publish- 
 ed a paper in which they give experimental evidence for the as- 
 symetry of diazo diethyl succinate* This is the first direct 
 evidence which has been produced of the assymetry of an alipha- 
 
 3 
 
 tic diazo compound. The work of Noyes and Marvel produced in- 
 direct evidence of the existence of such compounds by the pro- 
 duction of slightly active hydroxy esters by the treatment of 
 amino ester hydrochlorides with nitrous acid in such a way that 
 the diazo compounds were decomposed without being isolated. 
 
 The present work on aliphatic dizao compounds was started 
 before the appearance of the paper of Levene and Mikeska and it 
 was thought desirable to continue the work on the aliphatic 
 diazo compounds not only to verify their work, but also to pro- 
 duce other similar compounds and to produce further evidence to 
 show that the activity observed was actually due to a difference 
 in the nitrogen atoms in the molecule and not to some other 
 cause. 
 
 According to the Curtius formula for the aliphatic diazo 
 compounds two nitrogen atoms are attached to the same carbon 
 atom, while from the method of formation of the diazo compounds 
 one of the nitrogen atoms comes from ammonia while the other 
 comes from nitrous acid. These compounds have the following 
 electronic formulas:- 
 
*“t_ * 
 
 iT< 
 
 .H + 
 
 H + 
 
 'H + 
 
 + — +++ — 
 H - 0 - N = 0 
 
 The electronis formula for an aliphatic diazo compound 
 could then be written according to the Curtius formula. 
 
 r ^v*; 
 
 According to the Angeli-Thiele formula for the aliphatic 
 diazo compounds which has recently won a large number of new 
 adherents, the electronic formula could be written:- 
 
 R\- 
 
 \ C+ = N 2 N 
 BT 
 
 It can be seen that even with this formula a possibility 
 of assymetry exists. 
 
 The first aliphatic diazo compound, diazo camphor, was pre- 
 
 3 
 
 pared by Schiff and Meissen by the action of nitrous acid on 
 camphor-imide . It was Curtius however who first made a diazo 
 
 4 
 
 compound from an amino ester by the action of nitrous acid on 
 
 glycocoll ester hydrochloride. He made a thorough study of the 
 
 reactions of this compound as well as a number of other alipha- 
 
 8 
 
 tic diazo compounds and assigned the structure 
 
 R V c \~ R 
 
 if = U 
 
 The principal reactions on wnich the structure of the aliphatic 
 
 diazo compounds are based are as follows:- With iodine ethyl 
 
 diazo acetate gives di-iodo ethyl acetate upon reduction with 
 
 e 
 
 zinc and acetic acid the original amino ester is obtained. 
 
- 3 - 
 
 When reduced with sodium amalgam the hydrazinoacetate is ob- 
 
 7 
 
 tained • With concentrated hydrochloric acid it gives ethyl 
 
 monochloroacetate. By the action of water or dilute acids the 
 
 corresponding hydroxy ester is obtained. By the action of an 
 
 acyl chloride on two moles of ethyl diazo acetate, one mole of 
 
 ethyl monochloroacetate is formed and one mole of the acyl 
 
 diazo ester 8 
 
 R~C - C - C-0— R. 
 
 Ha 
 
 By the reduction of ethyl diazo acetate with palladium black 
 o 
 
 and hydrogen the hydrazone is obtained. 
 
 It was apparently this last bit of evidence which caused 
 
 Staudinger, so long an advocate of the Curtius formula, to lend 
 
 10 
 
 his support to the Thiele-Angeli formula, for in 1916 after 
 a complete study of the reactions of these compounds admitted 
 that Curtius* ring formation still explains matters best if it 
 it assumed that the ring can easily be ruptured under appropri- 
 ate treatment. In the same paper he states that the introduc- 
 tion of one or two carbonyl groups at the methylene carbon of 
 a diazo compound diminishes the color and lowers the reactivity 
 of the molecule, wnile in other cases the introduction of a 
 carboxyl adjacent to unsaturated groupings enhances the color 
 and reactivity. 
 
 In this series of work Staudinger and his co-workers tried 
 without success, to isolate isomeric diazo compounds, of the 
 
 l l 
 
 two structures R - C - R and R C - R 
 
 N = H 
 
 R 
 
 ui 
 
 N 
 

 
 
 
 
 
 ■ 
 
 . 
 
 
 
 
 
 
 
 
 
 ..... . ; 
 
 ■ , i 
 
 
 
 
 %< 
 
 ; f ...... , 
 
 . 
 
 " 
 
 
 
 
 : ; - ‘i 
 
 
 . . . . ' ■ . 
 
 
 
 
 
 
 . 
 
 
 * 
 
 i 
 
 
 ... • • 
 
 t 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 . 
 
 
 
 
 ■. . - £■ 
 
 V 
 
 ■ 
 
 - 
 
 : 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -• 
 
 
 
 
 ” 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 4 — 
 
 
 II THEORETICAL 
 
 
 Methods of Preparation j 2£ the Aliphatic Diazo Compounds . 
 
 The most gexieral method for the preparation of the alipha- 
 tic diazo compounds is that of Curtius toy the action of nitrous 
 acid on amino ester hydrochlorides. This method nas been ex- 
 tended so as to include diazo compounds prepared by the action 
 of nitrous acid on other amino derivatives, such as cyanides, 
 ketones, imides and amides. A general method for their prepara— 
 
 13 
 
 tion is that of v. Pechmann and a modification of this method 
 
 1 3 
 
 introduced by Oppe by which the diazo compounds, are produced 
 by the action of concentrated alcoholic or aqueous alkali or an j 
 etheral solution of sodium alkoxides on nitroso imides. The 
 other general method for the preparation of tne aliphatic diazo 
 compounds, that of oxidation of hydrazones with yellow mercuric 
 
 14 
 
 oxide is not applicable for the preparation of optically 
 active diazo compounds due to the fact that trie hydrazones are 
 symmetrical in structure. 
 
 The only pure diazo esters prepared in this work were ob- 
 tained by the Curtius method and purified by vacuum distillation 
 of the thoroughly washed and dried crude samples. 
 
 The following diazo esters were prepared:- 
 
 Impure ethyl and methyl esters of Y diazo valeric acid were 
 prepared by the treatment of the lactam of Y amino valeric acid 
 with sodium ethylate and methylate. No method of purification 
 could be found due to the extreme instability of the products. 
 
 Diethyl^ iazoglutarate was prepared by the action of 
 
- 5 - 
 
 nitrous acid d-diethyl glutamate hydrochloride according to the 
 
 Curtius method. The purified product from different prepara- 
 
 o o 
 
 tions had a specific rotation of + 0,85 to + 1*68 * 
 
 Dimethyl <=<diazoglutarate was prepared in the same manner 
 
 from the corresponding dimethyl ester hydrochloride* This sub- 
 
 o 
 
 •stance had a specific rotation of + 0,89 * 
 
 Diethyl «=< diazo succinate was prepared in a similar manner 
 
 from 1-diethyl asparate hydrochloride. The purified product 
 
 o 
 
 had a specific rotation of - 1.23 . 
 
 Ethyl^diazo n-caproate was prepared in the same way from 
 
 l-ethjrl «=><amino-n-caproate hydrocriloride and had a specific 
 
 0 0 
 
 rotation of - 1,89 • 
 
 Ethyl o< diazo-n-caproat e was prepared from the d-ethyl 
 
 0 
 
 ester hydrochloride and had a specific rotation of + 1,84 , 
 
 Ethyl diazo isocaproate was prepared from the levorota- 
 
 tory amino ester hydrochloride and had a specific rotation of 
 0 
 
 - 1,53 * 
 
 These diazo esters upon treatment with dilute sulphuric 
 acid all gave a mixture of an unsaturated hydroxy with the same 
 cirection of rotation as the amino esters and diazo esters from 
 which these were prepared, and of the same order of magnitude as; 
 the diazo ester. 
 
 The mixture of d-hydroxy glutaric esters and unsaturated 
 ester upon saponification gave sodium salts with the same direc- 
 tion of rotation as the amino acid, hut the rotation correspond-' 
 
 ed to only about 10--13 per cent of the pure active sodium salt, 
 
 products 
 
 The acid hydrolysis/from the other diazo compounds upon sap-j 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■- 
 
 - 
 
 . 
 
 
 
 
- 6 - 
 
 onif icat ion gave sodium salts which had the same direction of 
 rotation but in some cases the salts were not identified due to 
 lack of material. 
 
 Diethyl^iazoglutarat e upon reduction gave d-diethyl gluta-i 
 mate but the activity corresponded to only about 12 per cent of 
 the pure active amino ester. 
 
 The rotation of the diazo glutaric esters prepared cannot 
 be due to the presence of the amino ester as this product was 
 specifically tested for by the Van Slyke nitrous acid method, 
 after treatment with dilute acid to destroy the diazo ester, and! 
 the total amount of nitrogen obtained calculated as the amino 
 ester the amounts obtained were negligable, and moreover the 
 amino ester gives only a normal increase in rotation when added 
 to the diazo ester. The rotation can not be due to the presence 
 of a hydroxy ester as the rotations of the hydroxy ester prepar- 
 ed by treatment of the amino ester with nitrous acid so as to 
 decompose the diazo esters without isolation, were of the same 
 order as those of the diazo esters. This of course might sug- 
 gest that the same impurity caused the rotation in the two cases> 
 but it is hard to see how, even if this supposed impurity escap- 
 ed removal by distillation, it should give both an active hy- 
 droxy acid upon saponification and an active amino acid upon 
 reduction, and that the rotation obtained although of a different 
 amount corresponds at least approximately to the same percentage 
 of the active compound in the two cases. 
 
 The rotation cannot be due to the hydroxy acid as this com- 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 . 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 • v> t 
 
 
 V • 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ... . 
 
 
 , 
 
 : 
 
 
 
 ‘ 
 
 
 
 
 
 
 » 
 
 
 
 
 
 . 
 
 
 
 
 
- 7 - 
 
 15, le 
 
 pound, in the first place is levorotatory , and moreover it 
 
 certainly would be separated by distillation. The rotation 
 cannot be due to the presence of pyrrolidone carooxylic ester, 
 
 17 
 
 as this compound besides being levorotatory has a much higher 
 boiling point. 
 
 The arguments which have been advanced in the case of the 
 glutaric esters in the main hold good for all of the other diazo 
 esters prepared as well, though in some cases the diazo com- 
 pounds prepared were not as pure as was obtained in the case of 
 the glutaric esters, it was found in all cases that purification 
 
 had onljr a small effect on the rotation, presumedly due to the 
 
 active 
 
 fact, that the chief/ impurity, the hydroxy esters in all cases 
 had rotations of the same order as that of the corresponding 
 diazo compounds. 
 
 It has been rather a common observation tha'D in the distil- 
 lation of diazo esters even those that have been carefully dried 
 
 a part and in some cases nearly all of the diazo ester is decora- 
 
 18 , 18 
 
 posed with the production of a large amount of hydroxy ester 
 It was found in tnis work that when the diazo esters were treat- 
 ed with metallic sodium in ether or petroleum ether solution 
 that the ether solution became inactive long before all of the 
 diazo ester was destroyed. When the diazo ester is successively 
 treated with sodium methylate in ether solution and distilled 
 for from 4 to 6 times the diazo ester finally becomes entirely 
 inactive. When the diazo e3ter is reduced only approximately 
 12 per cent of the glutamic acid obtained is active, and approx- 
 
- 3 - 
 
 imately the same percentage of active hydroxy acid is obtained 
 by treatment with acid followed by saponif ication of the hydroxy 
 ester. Moreover we nave never obtained diazo esters showing 
 over 99 per cent of the theoretical amount of nitrogen by ana- 
 lysis. These results might be taken as evidence that the diazo 
 esters as ordinarily prepared and dried contained some and in a 
 few cases quite a large amount of the hydrated form, which might 
 be represented by the formula 
 
 R - § R 1 
 
 \l— N -OH 
 
 However, it would not appear likely that such a compound would 
 distill without entire decomposition, in fact it is usually as- 
 sumed that this type of compound is formed intermediately in the 
 formation of diazo esters, and then it is immediately and com- 
 pletely dehydrated. Attempts were made in this work to isolate 
 
 the benzoyl derivatives of the diethyl diazoglutarate, accord- 
 
 20 
 
 ing to the method used by Staudinger in the case of diazo 
 acetic ester. It is readily seen that a compound of this type 
 would not be formed from diazoglutaric esters according to the 
 Curtius formula. The attempts to isolate such a compound was 
 unsuccessful, although the mixture of diazo ester and benzoyl 
 bromide retained the diazo color after the benzoyl bromide odor 
 had disappeared. The bromoester was isolated by vacuum distil- 
 lation of the reaction mixture, but neither the residue from 
 the distillation of the bromoester or the original reaction mix- 
 ture evolved nitrogen either in the cold or when heated with 
 twenty per cent sulphuric acid. 
 
-9- 
 
 It has long been known that optically active hydroxy acids 
 may be obtained by the treatment of amino acids with nitrous 
 
 21 , 32 , 23 , 24,25 
 
 acid * Diazo esters may be obtained from almost 
 
 any of the amino esters and these give hydroxy esters when 
 treated with water or dilute acids* Optically active hydroxy 
 esters have been prepared by the action of nitrous acid in such 
 
 26,2 7 
 
 a. way that the diazo compound may be an intermediate product • 
 
 28 
 
 These facts are considered by some as evidence that diazo com- 
 pounds are intermediate products in the formation of hydroxy 
 acids when amino acids are treated with nitrous acid. However, 
 it should be noted that in most cases the hydroxy acid obtained 
 rotates in the opposite direction to that of the amino acid 
 from which it was prepared, and at least in most cases in which 
 hydroxy acids rotate in the same direction as the amino acids, 
 the direction of rotation of the amino acid itself is in doubt 
 as the direction of rotation may be changed by choice of solvent 
 or the formation of a salt with the amino or carboxyl groups. 
 
 In this work it was found in each case that the amino esters 
 gave hydroxy esters with the same direction of rotation as the 
 amino esters from which prepared, and the hydroxy esters in turn 
 gave hydroxy acids with the same direction of rotation. Levene 
 
 29 
 
 and Mikeska found that dextro diethyl asparate gave the d- 
 hydroxy ester going through the diazo ester. While it is known 
 
 30 
 
 that 1 -aspartic acid gives the 1-hydroxy acid . She aspartic 
 
 acid itself is strongly dextrorotatory in a decidedly acid sol- 
 ution. These facts makes it appear unlikely that diazo compound:; 
 
 are intermediate products in the conversion of free amino acids 
 into the hydroxy acids by treatment with nitrous acid. 
 
- 10 - 
 
 III EXPERIMENTAL 
 
 The first attempt made was the preparation of ethyl/diazo- 
 valerate, by the treatment of nitroso methyl 2 pyrrolidone with 
 an etheral solution of sodium methylate according to Oppe's 
 method. By this method it is believed both the diazo ester and 
 sodium diazo oxide were prepared but neither could be obtained 
 in a pure condition, owing to the extreme instability of the 
 products. 
 
 Preparation of / Amino Valeric Acid. 
 
 Y Amino valeric acid was prepared by the aluminium amalgam 
 reduction of the phenylhydrazone of levulinic acid according to 
 
 3 1 
 
 the method of Fischer and Groh . Using 116 grams of levulinic 
 acid dissolved in 750 cc. of water and adding this with effi- 
 cient mechanical stirring to a solution of 108 grams of phenyl 
 hydrazine dissolved in 750 cc. of water with just enough acetic 
 acid added to dissolve the phenyl hydrazine. The yield of pink-' 
 ish yellow crude phenyl hydrazone was 200 grams and was used foi 
 the reduction without purification. 
 
 The reduction was carried on using mechanical stirring, and 
 from 200 grams of the crude phenyl hydrazone we obtained in dif- 
 ferent runs from 60-70 grams of crude gamma amino valeric acid, 
 
 o 
 
 melting at 192-194 . Some difficulty was found in obtaining 
 suitable aluminium for the reduction. None of three different 
 samples of granulated aluminium of domestic manufacture would 
 

 ■ 
 
 
 
 
 
 ' 
 
 ■ 
 
 a — 
 
 . 
 
 
 
 
 
 
 - 
 
 •> 
 
 , 
 
 
 
 
 
 . 
 
- 11 - 
 
 react longer than a few minutes after amalgamation* Kahlbaum ' b 
 
 % 
 
 aluminium reacted properly as did aluminium turnings made from 
 aluminium bars and finely cut aluminium sheets of domestic man- 
 ufacture* 
 
 Preparation of Nitroso Methyl 2 Pyrrolidone 
 
 This compound was prepared bjr the action of nitrous acid 
 upon the aqueous solution of the lactam of gamma amino valeric 
 
 33 
 
 acid according to the method of Tafel • From 20 grams of gamma 
 amino valeric acid we obtained 13 »1 g of the lactam boiling 
 138-140° 22 mm. 77 per cent of the theoretical amount. From 
 this we obtained 6 grams of nitroso methyl 2 pyrrolidone as a 
 yellow oil which could not be crystallized. The product gave 
 Libermann's nitroso reaction. The product was analyzed by 
 treating with 10 per cent sodium hydroxide and measuring the 
 evolved nitrogen. 
 
 Analysis: .0889 grams of substance gave 13*05 cc. nitrogen 
 at 27*5° and 747 mm. 
 
 Attempts to Prepare Diazo Ethyl Valerate and Diazo 
 
 Methvl Valerate . 
 
 5. g of nitroso methyl 2 pyrrolidone prepared as just des- 
 cribed was dissolved in 3°0 cc. of very carefully dried ether. 
 
 o _ 
 
 The solution was cooled to -15 to -20 and a solution of .8 g 
 of sodium in 10 cc. of absolute ethyl alcohol was added in small 
 portions. The ether solution became colored a reddish yellow. 
 
 After thirty minutes carefully dried carbon dioxide was passed 
 into the solution, whereupon the ether solution almost complete- 
 
- 12 - 
 
 ly lost its color. After filtration in dry air the ether solu- 
 tion was concentrated by evaporation in a vacuum dessicator. A 
 small amount of a sharp smelling liquid of a slightly orange 
 yellow color was left. The product would not solidify upon 
 cooling with freezing mixture. When treated with dilute acids 
 there was a small evolution of nitrogen. The product upon 
 vacuum distillation was a colorless liquid. 
 
 A number of other attempts were made by varying the amounts 
 of sodium and alcohol used, and also by the use of sodium in 
 methyl alcohol, but in all cases the large part of the product 
 was decomposed upon the addition of the carbon dioxide. 
 
 Probably the best yield of the diazo compound was formed 
 by the use of about *1 g sodium methylate in a rather large 
 excess of methyl alcohol. In this case the ether solution was 
 colored a very deep cherry red. A part of this solution was 
 treated with carbon dioxide in the usual way with same results 
 as above, the other portion of the solution was concentrated 
 to a small volume in vacuum dessicator, but it was impossible 
 to obtain ary separation* The addition of water caused an evolu-** 
 tion of nitrogen. 
 
 Attempts were also made by using just slightly less than 
 the theoretical amounts of sodium methylate or ethylate to ob- 
 tain the pure sodium diazo oxide compound but in all cases a 
 mixture was obtained. 
 
 O.O 569 of the purest material obtained gave 6.1 cc of nitro- 
 c 
 
 gen at 24 and 743 mm. when treated with dilute sulphuric acid. 
 
- 13 - 
 
 The sulphuric acid solution was evaporated to dryness and ignit- 
 ed and gave *0272 g of sodium sulphate. This corresponds rough- 
 ly to two moles of sodium to one of diazo. From the nature of 
 the compound which was a light yellow amorphous solid, quite siiQ" 
 ilar to the product obtained when a diazo ester is treated with 
 sodium methylate, it probably is a compound of the type of the 
 potassium^ diazo acetate mixed with sodium ethylate, which has 
 been prepared from diazo acetic ester by treatment with potas- j 
 
 33,34 
 
 sium ethylate . This compound was decomposed when treated 
 
 with dilute acids or water, it gave a turbid solution in abso- 
 lute alcohol which could not be clarified by filtering, and was 
 either decomposed or insoluble in all of the common organic 
 solvents. As no method could be found of purifying the diazo 
 compounds obtained the work on these compounds was discontinued. 
 
 d-Glutamie acid was chosen as the starting material in a 
 large part of the work because from its ester hydrochloride the 
 diazo ester can be obtained in fair yields. The active amino 
 acid can be obtained in a high state of purity directly and 
 with comparative ease, and further it was thought advisable, in 1 
 view of the results of Noyes and Marvel, to prepare the diazo 
 ester of a dibasic acid in hopes that the results might be more 
 positive than in the case of the monobasic acid esters prepared 
 by them. 
 
 In most cases the amino ester hydrochloride was made direct- 
 ly from the acid hydrochloride and the diazo ester made from 
 the recrystallized amino ester hydrochloride. Trial' runs were 
 

 
 
 
 
 
 i 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 ■ *, - • 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 
 : 
 
 
 
 
 
 . 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 I 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 -s 
 
 
 
 
 
 •< 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 * 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 14 - 
 
 made, however, in which the amino acid was isolated from the 
 acid hydrochloride for esterification and the ester hydrochlor- 
 ide was made toy decomposing the crude ester hydrochloride accord- 
 
 38 3 6 
 
 ing to Fischer's method or Foreman's method and vacuum dis- 
 tilling the amino ester and preparing the ester hydrochloride 
 by passing dry hydrochloric acid gas into the solution in dry 
 ether. Identical results as far as activity and purity of the 
 diazo ester were concerned were obtained by using any one of 
 the methods. The yields obtained by the method given, however, 
 were much better and the method requires much less time than vhen 
 any of the other methods \ are used, mainly due to the solubili- 
 ties and the extreme sensitiveness of glutamic acid esters to 
 alkali. Better results were obtained by Foreman's method than 
 by Fischer's method for isolating the free amino esters, but it 
 is quite difficult to remove all of the hydrochloric acid by 
 solid barium hydroxide.* 
 
 The use of sulphuric acid for the diazotazation was found 
 
 3 7 j 
 
 preferable to the use of acetic acid as used by Uoyes and Marvel 
 because of the difficulty of removing all of the acetic acid 
 from the ether solution, and also more particularly because with 
 the use of acetic acid the ether solution always contained some 
 of the amino ester, in some cases as high as four per cent of 
 the product. This necessitated repeated washing with cold dilute 
 acids for the removal, and a consequent production of a large 
 amount of hydroxy ester. It was found that in the case of di- 
 ethyl aiazoglutarate a nearly complete purification 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
could be accomplished with only a slight loss of diazo 
 
 ester by diluting the dried ether solution of the diazo ester 
 to a large volume with anhydrous ether, and adding to the dilute 
 solution the calculated amount of a H ether-methyl alcohol solu-i 
 tion of sodium methylate to form presumedly the sodium alkoxide 
 salt of the hjrdroxy ester. Upon the addition of the sodium 
 methylate solution the ether solution was turned from a bright 
 citrous yellow color to a light reddish brown, but upon stand- 
 ing a yellow precipitate separated, and the ether solution was 
 left only slightly darker than the original color. The ether 
 solution was then filtered and washed with cold water as long 
 as the water was at all colored, then carefully dried over cal- 
 cium chloride, the ether evaporated in vacuo on a water bath 
 o 
 
 heated to 35 , and the product filtered and dried by drawing a 
 stream of dry air through the product under a pressure of 2 mm. 
 for 3 hours. The product was then submitted to distillation, I 
 using a pressure at least as low as 0.2 mm. If analysis for 
 
 38 
 
 diazo nitrogen by the sulphuric acid method was low the puri- 
 fication was repeated. After pure samples of diazo ester were 
 once prepared the refractive index was used as a control test of 
 purity. The purification of the diazo ester by means of sodium 
 ethylate is open to the criticism that the diazo esters them- 
 
 39 , 40 
 
 selves react with sodium ethylate , however, when the proper 
 
 amount of the reagent is added a decided purification is obtain- 
 ed, as shown by analysis, density and refractive index. Moreover 
 nearly identical results have been obtained by repeated fraction- 
 

 
 
 
 
 
 ! I ! 1 
 
 
 
 
 
 
 
 
 t . ... 
 
 - .a 
 
 
 
 
 » 
 
 
 
 . ■ ■■(.«. 1 
 
 
 . - * ■ • • 
 
 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 v 
 
 
 
 
 
 
 
 > 
 
 
 
 
 
 . 
 
 
 
 * 
 
 
 
 
 
 
 • ' r ~ 
 
 
 
 
- 16 - 
 
 al vacuum distillation, but the amount of pure diazo dietnyl- 
 glutarate obtained by this method is small » In the case of the 
 other diazo esters prepared the yields of pure product obtained 
 by fractional vacuum distillation are much better* 
 
 DERIVATIVES OP d -GLUTAMIC ACID. 
 
 This acid has been prepared by the hydrolysis of a large 
 number cf protein products, including gliadin. For this work 
 it was prepared by hydrolysis of the crude flour protein ob- 
 tained by simply washing the flour with water to remove the 
 starch. 
 
 Preparation of d-Glutamic Acid Hydrochloride. 
 
 24 pounds of hard wheat flour in the original muslin sack 
 are soaked for 30 minutes in a sink filled with water and then 
 vigorously kneaded, with frequent changes of water until very 
 little more starch passes through the sack. The lumps are care 
 fully broken up and the product kneaded until it has an even 
 rubbery feeling and has no tendency to stick to the fingers# 
 
 The rubbery mass is then removed from the sack and kneaded in 
 the sink to remove the remainder of the starch and an 3 ^ lumps 
 present carefully broken up. 
 
 The crude, wet gluten, weighing about 4500 grams, is then 
 divided into two equal portions and placed in two 5 liter 
 flasks, and to each of the flasks are then added 2 liters of 
 concentrated hydrochloric acid, the the mixture heated on the 
 water bath for about two hours or until the purple coloration 
 has disappeared, and all has gone into solution except black 
 

 
 
 
 
 
 ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 .. . V 
 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-17- 
 
 humus matter. The mixture is then heated to boiling under re- 
 flux condenser for 24 hours, and filtered hot either on a 
 Buchner funnel fitted with a "filtros" plate or with three 
 thicknesses of filter paper. The humus matter is then heated 
 on the water bath for 10 minutes with an equal weight of water 
 and again filtered and washed with hot water until filtrate is 
 only slightly colored. The combined filtrates and wash waters 
 are then concentrated under diminished pressure to a volume of 
 2000 cc., poured into a large beaker, cooled, packed in ice, 
 and saturated with gaseous HC1 and allowed to stand in the ice 
 box for at least 12 hours, and filtered either upon a M filtros M 
 plate or three thicknesses of filter paper, using strong suc- 
 tion and pressing the product down until no more liquid runs 
 through. The crude glutamic acid hydrochloride is then mixed 
 with enough ice cold alcoholic hydrochloric acid to thoroughly- 
 wet it and again filtered and washed with cold alcoholic hydro- 
 chloric acid, and then with ether. The crude product is then 
 dissolved in the smallest possible amount of boiling water, 
 cooled, packed in ice and saturated with gaseous HC1, and allow 
 ed to stand in the ice box for 2 hours, and again filtered and 
 washed as before, the washing with alcoholic hydrochloric acid 
 being carried out until the filtrate is nearly colorless. After 
 one more reprecipitation and washing the product should be per- 
 fectly white. If it is not or the filtrate colored more than 
 yellow the product should be redissolved and reprecipitated, 
 sometimes boiling the solution with bone black and filtering 
 

 - 
 
 
 
 w 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 . 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 18 - 
 
 before reprecipitating will assist in the decolorizat ion, but 
 usually is unnecessary. The filtrates from the reprecipitations 
 are concentrated under diminished pressure and the glutamic acid 
 hydrochloride precipitated in the same way as given above, except 
 that it is possible to evaporate the solutions nearly or quite 
 to dryness, particularly in the later filtrates* The combined 
 fractions of the precipitates obtained from the mother liquors 
 are washed with cold alcohol, and then heated for l/2 hour with 
 an equal weight of absolute alcoholic hydrochloric acid to es- 
 ter ify the glutamic acid filtered from unesterified matter. Then 
 the alcohol distilled under diminished pressure and the sirupy 
 mass of ester hydrochloride mixed with ten volumes of 10 per cent 
 HC1, hydrolyzed by heating on the water bath for 5 hours, the 
 product concentrated under diminished pressure, and the glutamic 
 acid precipitated as the hydrochloride and washed in the usual 
 way. The product may be dried on porous plates for esterifica- 
 tion. Yield of pure, dry d-glutamic acid hydrochloride 285-310 
 grams. 
 
 It is found inadvisable to reconcentrate the original 
 mother liquors as the material is so viscous that it is very 
 difficult to handle and moreover very little additional product 
 is obtained. For the alcoholic hydrochloric acid used for wash 
 purposes the distillate obtained from esterification of glutamic 
 acid was utilized. 
 
 In the hydrolysis of the gluten it is advisable to reflux 
 the mixture for at least 24 hours, for although nearly as good 
 

 
 
 
 
 
 
 . r . 
 
 
 . 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 / 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 • 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 19 - 
 
 a yield may be obtained by considerably shortening the time, 
 the liquid is so viscous that the filtration of the glutamic 
 acid hydrochloride is very difficult, and the product carries 
 much more foreign matter which necessitates at least one more 1 
 reprecipitation to obtain the pure product. 
 
 It should be noted that the best grades of hard wheat bread 
 flours will give somewhat higher yields of glutamic acid than 
 the cheaper, due to the higher content of gliadin in the gluten. 
 The difference between the yields from the best and madium 
 grades however is not great. 
 
 The pure product dried in desiccator over sulphuric acid 
 
 o 
 
 and calcium carbonate sinters at 202 - 205 and melts upon 
 
 o 
 
 rapid heating at 210 • 0.6013 g of the product made up to a 
 
 o 
 
 volume of 10.00 cc. with water gave a rotation of + 1.47 in a 
 
 o 
 
 1 dm. tube in sodium light at 22 0 ; f ®< + 24.44 . 
 
 \ 
 
 Analy sis ( Kj e ldahl ) 
 
 Substance 0.2542, 0.2479: 13.35 cc., 13. 03 cc., 0.1040 N 
 
 H3SO4 
 
 Calculated for CbHio 04 NC 1 : N, 7.63. Found 7.65, 7.66. 
 d -Diethyl Glutamate Hydrochloride. 
 
 This ester hydrochloride was prepared by a modification of 
 
 4 1 
 
 the usual method which was found to give equally good results 
 with considerable smaller amounts of alcohol. 
 
 50 g of d-glutamic acid hj^drochloride ( r c=a <'I3 d + 24.44) 
 was heated on the water bath with 100 cc . of absolute alcohol 
 which had previously been saturated with dry hydrogen chloride, 
 until the acid all dissolved and then 200 cc. of absolute alco- 
 

 
 
 
 
 
 . 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 * 
 
 > 
 
 
 
 
 
 
 
 » * 
 
 < 
 
 i 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 20 - 
 
 hol were added and the heating continued for one hour. The mix- 
 ture was then concentrated to a thick sirup by evaporation under 
 diminished pressure, 100 cc. of absolute alcohol were then add- 
 ed and the mixture again warmed on the water bath for one hour, 
 and then the concentration under diminished pressure repeated. 
 Upon cooling the crude ester hydrochloride sometimes solidified. 
 Whether it solidified or not the crude product was dissolved in 
 an equal weight of chloroform by warming on water bath, and then j 
 after cooling about 30 cc, of dry ether was added, which precip- 
 itated a gummy mass containing some diethyl glutamate and all 
 of the impurities and colored materials. The clear solution was; 
 then filtered and the diethyl glutamate hydrochloride precipi- 
 tated by adding ether as fine white needles. The gummy slightly- 
 colored mass obtained upon the addition of the first portion of 
 ether was purified by dissolving in chloroform ana reprecipitat- 
 ing as before. Yield 47-55 grams (72. 5 - 85 per cent of the 
 calculated amount). M. P. 96-98°, Por analysis the product was 
 dried in vacuo over sulphuric acid and calcium carbonate. 
 
 Analysis (Kjeldahl) 
 
 Substance 0,2671> 0,2871: 11. 09 cc., 11.92 cc., 0,1040 N 
 H3SO4 
 
 Calculated for C0H18NO4CI : IT, 5 . 85 , Pound, 5 . 86 , 5 , 86 . 
 
 Other runs were made in which the glutamic acid was isolat- 
 ed from the hydrochloride by the addition of the calculated 
 amount of NaOH to the aqueous solution of the hydrochloride, and 
 
 42 
 
 by the ammonia method , and then esterified in the usual manner 
 The results were essentially the same as by the method outlined. 
 

 
 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 / 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 1 
 
 . . 
 
 . 
 
 . 
 
 
 
 
 
 
 
 
 
- 21 - 
 
 Other runs were also made in which the free ester was isolated 
 
 43 
 
 from the crude ester hydrochloride by Fischer's method , and 
 vacuum distilled and the hydrochloride prepared by passing dry 
 hydrogen chloride into the solution in dry ether, The results 
 
 i 
 
 as far as activity of the diazo ester was concerned were iden- 1 
 tical, but the yield was considerably lower, due to the solubil- 
 ity and sensitiveness to alkali of the glutamic ester* 
 
 Diazo Diethyl Glutarate 
 
 50 grams of diethyl glutamate hydrochloride is dissolved 
 
 in laO cc. of water and to this was added 25 grams of sodium 
 
 acetate, and the mixture surrounded by an ice salt freezing mix- 
 
 o 
 
 ture cooled to -10 and then 25 grams of sodium nitrite and J00 
 cc. of ether are added and the mixture gently stirred by mechan- 
 ical stirrer in such a way that the ether layer was not mixed 
 with the lower layer. Then during the course of 1 hour 50 cc. 
 of 10 per cent sulphuric acid were added, and the stirring con- 
 tinued for 2 hours. The ether layer was then separated and ! 
 
 washed first with 5 2 5 cc. portions of ice cold N sulphuric acid 
 then with saturated sodium bicarbonate until very little CO 2 
 is evolved, and then with 5 per cent sodium carbonate until the 
 sodium carbonate layer was distinctly colored, and then with 
 water. The ether layer was then dried first with calcium chlor- 
 ide containing a little anhydrous barium hydroxide, and finally 
 over fused calcium chloride. The ether solution was then dilut- 
 ed with anhydrous ether to a volume of exactly 1 liter, and 
 exactly 10 cc. of the ether solution drawn off by means of a 
 pipette and the ether evaporated off in vacuum desiccator over 
 

 
 - 
 
 
 * 
 
 
 - 
 
 . 
 
 
 
 . 
 
 
 
 ' 
 
 
 - 
 
 * i 
 
 ■ 
 
 * 
 
 
- 22 - 
 
 sulphur ic acid and sodium hydroxide* This sample was then anal- 
 yzed for nitrogen by the sulphuric acid method* The difference 
 between the theoretical amount of nitrogen and that found was 
 considered to be due to hydroxy ester and the calculated amount 
 of a H ether - methyl alcohol solution of sodium methylate added 
 to combine with the hydroxy ester* The sodium methylate solu- 
 tion was made by dissolving 2 *30 grams of pure sodium in 21 
 grams of absolute methyl alcohol, and diluting to 100 cc. with 
 anhydrous ether. After the addition of the sodium methylate 
 solution to the ether solution of the diazo ester the mixture 
 was allowed to stand for 2 hours and then filtered. The ether 
 solution was then washed with water and again dried over fused 
 calcium chloride, and then the ether evaporated off in vacuo 
 and the diazo ester dried by evacuating the flask to 2. mm. and 
 drawing a stream of carefully dried air through the product for 
 5 hours. The product was then filtered to separate a solid pre- 
 cipitate, probably diethyl aziglutarat e, as it appears exactly 
 like the product obtained under similar circumstances from di- 
 
 44 
 
 ethyl diazo succinate . The ether solution of this solid pro- 
 duct was inactive*. The crude diazo ester, which analysis by 
 the sulphuric acid method shovted to be, in different runs from 
 92 - 96 per cent, pure was then vacuum distilled, using a pres- 
 sure at least as low as 0.2 mm. The purified ester boils at 
 
 92 - 93 a t 0.1 mm. The yield of crude diazo ester before treat- 
 ment wi.th sodium methylate varied in different runs from 15 - 21 
 grams. The yield of pure vacuum distilled ester amounts to 8 — 
 

 
 
 , 
 
 # 1 I 
 
 
 
 ' 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 . 
 
 
 
 ‘ 
 
 
 
 
 
 y 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 , • • 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■ , 
 
 
 . 
 
 - 
 
 
 
 
 
 
 ■ 
 
 ' 
 
 
 
-23- 
 
 12 grams when the distillation goes well* Sometimes however 
 without apparent reason decomposition takes place even with a 
 vacuum of *1 mm and if tnis takes place, even lowering the pres- 
 sure ts>o .01 mm or less, fails to yield a pure product and in 
 this case the distillate contains besides diazo ester, hydroxy 
 ester, and probably the unsaturated ester as the product after 
 destroying the diazo ester 1 by treatment with dilute acid decol- 
 orizes permanganate solution but had nc. action oaoromine in car- 
 bon tetrachloride. Thirty preparations of tnis diazo ester 
 were made, using both sulphuric acid and acetic acid for the 
 diazot izat ion, and the only cases in which an inactive diazo 
 ester were obtained was in the cases where^good vacuum for dis- 
 tillation was not available. Three preparations which were 
 distilled tuth ;a presaurg:. of 1.-3, mm besides not giving pure 
 samples due to decomposition the products were inactive. Of 
 the preparations which were distilled with a vacuum of .2 mm 
 
 or less the rotation of the samples varied from [ C ^<J D + 0.37° to 
 o 
 
 +1.68 . Three preparations were made in which the analysis 
 showed to be 9^*5 - 99 per cent pure and the rotations varied 
 in these cases f r om r <=> <~^ + 1.38 to + 1.68 and these prepara- 
 tions as well as the others showed substantially the same rota- 
 tion in the pure state as in the crude state (before distilla- 
 tion). Six oth^r preparations were made which the analysis 
 
 showed to be 99 - 98 per cent'pure and these preparations all 
 
 0 0 
 
 had rotations of + 0.8? to + 1.68 . A typical set of 
 
 data on one sample are given:- 
 

 
 
 
 • 
 
 
 , 
 
 
 
 
 • 
 
 
 
 
 
 
 
 ■ 
 
 
 - 
 
 * •' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-24- 
 
 o 0 
 
 d 1*124; Rotation in a 1. dm tube in sodium light at 20 
 
 + 2.01°; t><3 X) 10 + 1.68° i 4° 1.4730. 
 
 Substance 0,11?, 0.1088 : 15*25 cc of nitrogen at 24° 
 and 747 mm 
 
 Calculated for CeHi+O+Hal H, 13»08* Found: lJ.OO, 12*92 
 (Sulphuric acid method) 
 
 Substance 0.2280, 0.2047 : 0.4206 C0a, 0.1599 Ha 0 and 
 O.5785 C0a,. 0.1250 KaO 
 
 Calculated for C^Hi-tO^Na : c, 50.44, H, 6. 59* Found: C, 
 50.55, H, 6.86; C, 50.40, H, 6.78. 
 
 Dumas Method 1 
 
 Substance 0.2117, 0.1989.* 25.22 cc H fat 25° and 744 mm., 
 25.80 cc II at 24° and 759 mm. 
 
 Calculated for C9H14O4H2: N, 15.08. Found II, 15*15> 15*21 
 Large samples were run with particular pains to determine 
 hydrogen. 
 
 Substance 0.5285, 1.0015 : 0.5148 HaO, 0.5994 HaO 
 Calculated for C9H14O4II3 : H, 6.59* Found, H, 6.62, 6.65* ■ 
 The residues from the sulphuric acid nitrogen det erminat ioj i 
 were neutralized with sodium hydroxide and concentrated under 
 diminished pressure and made up to a volume of 5*00 cc and 2 
 cc samples run on a micro Van Slyke machine. 
 
 o 
 
 Substance .0447, 0,0447 : 0,01 cc nitrogen at 24 and 74? 
 ram., 0,015 H at 24° and 747 mm. 
 
 Per cent diethyl glutamate in sample: 0,10 per cent. 
 
 Molecular Weight by Boiling Point of Ether Method. 
 
 0,6494 g of diazo ester raised boiling point: of 68.4 g of 
 etner .0910, Mol. wt.'220. Repeated experiment and boiling 
 point raising was .095°. Mol. Wt. 215.5. 0,9788 g of diazo 
 

 / 
 
 
 . 
 
 
 
 \ 
 
-25- 
 
 ester raised the boiling point of 69*5 g of ether 0.136 . hoi. 
 wt . 2 18 . 
 
 Calculated for CaHi+CUNa : 214.15 
 
 Samples of the diazo were tested for halogen both by 
 Beilsteiii copper wire method and sodium fusion and showed no 
 halogen. 
 
 Treatment of Biethyl Diazoglutarate with Dilute Sulphuric Acid. 
 
 Fifteen grams of the optically active diaso esterfochJ d 
 0 
 
 + I.80 were added to 100 cc. of 20 per cent sulphuric acid and 
 
 shaken at intervals until the product lost its yellow color, 
 
 the product was then extracted with ether, the ether solution 
 
 dried over anhydrous sodium sulphate, the ether evaporated on 
 
 the water bath. Yield 7 grams. The crude product was filtered 
 
 0 
 
 and roation taken in a 1 dm. tube in sodium light + 3*30 
 
 The product was then vacuum distilled and 5 grams of product 
 
 0 
 
 boiling at 90-95 a t 0.2 mm were obtained. 
 
 20° ; 
 
 d 1.072; Rotation in a 1 dm. tube in sodium light 
 
 o 
 
 was + 1.28 ; 
 
 The product was again vacuum distilled and 4 grams of pro- i 
 
 o 20° 
 
 duct boiling at 90.5 - 9i»5 at 0.2 mm were obtained, d 40 
 
 3° 
 
 1.072; hp 1.4484. Rotation in a 1 dm. tube in sodium light 
 
 O 0 r 20 0 
 
 at 20 was + I.29 ; + 1.07 . The product had no action 
 
 with a solution of bromine in carbon tetrachloride in the cold, 
 but readily reacted with dilute 1 per cent potassium permangan- 
 ate. The product prepared using IT sulphuric acid for the 
 hydrolysis gave identical results/ and the purification by steam 
 
 -J 
 
-26- 
 
 distillation gave identical results* 
 
 Substance 0.1731, 0,1749; C0 2 , 0.3445, 0.3493* HaO, 
 
 0.1156, 0.1168 
 
 Calculated for CeHi404l C, 5o»10, H, 7*57 
 Calculated for C 7 H 10 O 4 ! C, 53*10; H, 6*33 
 The analysis reaction with potassium permanganate and the 
 decrease in rotation upon distillation which does not change 
 with further distillation indicates that the product is a mix- 
 ture of diethyl glutaconate and the lactone ester^ ethyl tetra— 
 hydro-5-keto-2-furancarboxylate ). 
 
 Saponification of the Acid Hydrolysis Products of Diethyl Diazo)-- 
 glutarate. 
 
 2.0 g of the acid hydrolysis products from the preceding 
 experiment were treated with (9.-6 ec. of pure IT alcoholic 
 sodium hydroxide (from sodium) and the mixture allowed to stand 
 at room temperature until the solution was neutral to phenol- 
 phthalein. 
 
 The sodium salt starts to precipitate immediately after 
 
 mixing. After the saponification was completed, the sodium salt 
 
 was filtered off and washed with alcohol and then with ether, 
 
 and the product dried in desiccator over sulphuric acid. Yield 
 
 0.9 grams (SOper cent of the calculated amount). 
 
 O. 585 O g of the sodium salt dissolved in water and made up 
 
 0 
 
 to 5*00 cc had a rotation of + .14 in a 1 dm tube in sodium 
 0330 45 
 
 light at 23 ;[c*<J D + 1,20 . Pischer and Warburg gives the 
 
 0 
 
 rotation of l-sodiumo<hydroxyglutarate as - 8.65 , 
 

 - 
 
 
 
 
 
 
 
 
 
 
 « 
 
 . 
 
 ■ 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 
 • 
 
 
 
 
 
 
 
 
 
 
 
 ‘ t 
 
 
 « 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 . 
 
 
 
 
 
 
 
 , 
 
 
 
 
 
 4 
 
 
 
 
 . 
 
 
 
 
 
-27- 
 
 therefore the salt prepared, is about 13 per cent active* Ihree 
 
 bther preparations of this salt were made and the rotation was 
 
 o 
 
 always between + 1*0 and + 1.20 * 
 
 The product was tested for amino nitrogen in a micro Van 
 
 Slyke machine and showed no amino nitrogen. The product gave 
 
 no test for nitrogen after a sodium fusion. 
 
 Substance O. 5833 , 0.4461: 0 . 4329 , 0.3342 ttaaSCU 
 
 Calculated for CeHeO e J3a 3 : Ha, 23 . 97 . Found 24.14, 24.21. 
 
 In the first preparation of the sodium salt alcoholic 
 
 sodium hydroxide was used which had been prepared some time 
 
 before from ordinary " C.P. M sodium hydroxide. A sodium salt 
 
 0 
 
 was obtained which had a specific, rotation of 8.36 which com- 
 
 4 6 
 
 pared well with the value given by Fischer for the pure active 
 sodium salt. The analysis for sodium however was slightly too 
 high. Another preparation from the same hydroxy ester with 
 the pure sodium hydroxide gave the results shown above. The 
 descrepency was evidently due to the presence of sodium carbon- 
 ate in the sample prepared with the impure sodium hydroxide. 
 
 0 
 
 As' it was found possible to get rotations as high as foci] + 40,, 
 by the addition of sodium carbonate to the solution of the 
 sodium <=< hy dr oxy glutarate. This great influence on the rota- 
 tion of hydroxy acids by foreign salts has been studied in 
 
 46 , 47 , 48, 40 
 
 detail 
 
 For comparison with the product obtained by hydrolysis of 
 the diazo ester, the amino ester hydrochlor ide was diazotized 
 in such a way that the diazo ester was decomposed without being 
 isolated. 
 

 
 
 
 
 ■ ■ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ' 
 
 
 
 
 
 
 
 
 
 - 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 . 
 
 
 
 
 
 
 * 
 
 
 
 
 
 
 
 
 
 ■ ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 23 - 
 
 30 g of d-diethylglutamat e hydrochloride was dissolved in 
 
 o 
 
 320 cc of N sulphuric acid and solution cooled at 0 and then 
 
 to the solution were added slowly 18 g of sodium nitrite dissolv 
 
 0 
 
 ed in 43 cc of water. The mixture was allowed to stand at 0 
 
 for 1 hour after the addition of the sodium nitrite and then 
 
 removed from the cooling hath, and allowed to stand at room tem- 
 
 0 
 
 perature for 3 hours, and finally warmed to 40 for 1 hour, l’ne 
 
 mixture was then extracted with ether, the ether solution dried 
 
 over anhydrous sodium sulphate and the ether evaporated on 
 
 water bat^h and the product vacuum distilled, collecting frac- 
 
 o 
 
 fcion boiling at 90-95 at .2 mm. Yield 3 grams. This fraction 
 
 0 
 
 was redistilled collecting fraction boiling at 90.5 - 91*5 
 
 .2 mm. Yield 5 g. 
 
 20 ° 20 ° 
 
 d 1 . 072 ; nj 1 .4485; Rotation in a 1 dm. tube in 
 
 o o _ _23° O 
 
 sodium light at 23 +2.04 D + 1.90 . 
 
 Substance : 0 . 1966 , 0 . 1780 ; C0 2 , 0*3917* 0.3551; HaO, 0.134*, 
 0.1189 
 
 Calculated for CeHieOs : C, 52.91, H, 7*90. Found: C, 54.34 
 
 54.40 ; H, 7*52, 7*42. 
 
 The product was saponified as described in the preceding 
 experiment. From 3 grams of the ester 1.1 gram of sodium salt 
 was' obtained. 
 
 Substance : 0*3242 : 0.2417 Ha a S04 
 
 Calculated for CcHeOeNaa : Na, 23 . 97 . Found: Ma, 24.18. 
 
 0.5672 dissolved in'water volume of solution 5. 00 cc. 
 
 0 0 23 
 
 Rotation in a 1 dm. tube in sodium light at 23 + *21 p 
 
 o 
 
 1.85 . 
 

 
 
 
-29- 
 
 Reduction of Diethyl Diazoglutarate 
 
 5 . g of the diazo ester was dissolved in cc of ether and 
 
 BO 
 
 1*9 g of aluminium amalgam which had been freshly prepared 
 and washed with alcohol were added* There is a vigorous reac- 
 tion with a copious evolution of ammonia* If the reaction became 
 too vigorous the contents of the flask were diluted with ‘dry 
 ether. The flask was frequently shaken for four hours wirh the 
 occasional addition of a drop of water, 1 cc of water was then 
 added and the flask allowed to stand overnight. The ether sol- 
 ution was then filtered and the aluminium hydroxide washed with 
 ether. The ether solution was then evaporated in vacuo, the re- 
 sidue had the appearance and odor of; diethylglutarate. 2*7141 
 g of residue made up to 5*00 cc with ether had a rotation of 
 + 0.90° in a 1 dm. tube. To the residue were added 20 cc of 10 
 per cent hydrochloric acid, and the acid solution extracted with 
 ether, to remove the hydroxy ester. The acid solution was then 
 heated on the water bath for 5 hours and the solution evaporated 
 nearly to dryness under diminished pressure. Upon cooling beau- 
 tiful white crystals formed on walls of flask which had the 
 characteristic taste of glutamic acid. The crystals were washed 
 from the flask with a little alcohol and ether added to complete 
 the precipitation. Yield from different preparations .75 -1*1 
 g (30 - 43 per cent of the calculated amount). The product was 
 dissolved in water and reprecipitated by adding alcohol and then 
 ether. 
 
 0.2511 g. dissolved in water and made up to a volume of 5. 00 
 

 
 
 
 
 u'» ,'v.' 
 
 
 
 
 
 
 
 
 • v •«**.- 
 
 J 
 
 * 
 
 * • V J> • 
 
 - 
 
 > t • . . ■ • 
 
 . 
 
 
 
 V. . 
 
 
 . . ■■ 
 
 
 . . , 
 
 w 
 
 . . . - 
 
 . 
 
 • % 
 
 
 . , 
 
 ... V- * 
 
 
 
 
 
 i. . 
 
 
 . i 
 
 
 
 
 
 
 
 
 
 
 
 
 C) " 
 
 
 
 
 
 
 
 
 
 
 
 
-30- 
 
 o 
 
 cc had a rotation of + .16 in a 1 dm. tube in sodium light at 
 
 o 2 3 o 
 
 23 ; + 3*20 . 
 
 •3829 g dissolved in water, volume of solution 3*00 cc had 
 
 0 0 
 
 a rotation of + . 36 in a 1 dm. tube in sodium light at 24 ; 
 
 24 0 
 
 [ c * d o + 3.10 . 
 
 The rotation of the glutamic acid hydrochloride from 3 other 
 
 0 0 
 
 runs varied fromcpOL + 2.90 to + 3. 20 • 
 
 Substance 0.1134, 0.1214 : 5*89 cc., 6,27 cc. 0.1040 N H 2 SQ 4 
 Calculated for C 15 H 10 O 4 NCI : N, 7*63* Found 7 •36, 7*32. 
 
 Attempts to Prepare Diethyl Diazoglutarate by Oppe's Method. 
 
 Bi 
 
 Ethyl 5 pyrrolidone 2 carbo^ylate. Fischer and Bolhner 
 have prepared this compound by heating of diethyl glutamate and 
 found that it was not racemized in the preparation as it gives 
 d-glutamic acid with full activity upon hydrolysis. 
 
 15 g of d-diethyl glutamate was heated for 20 minutes on 
 
 0 
 
 an oil bath to 160-170 under a pressure of 20 mm with a water 
 
 pump, the flask was then evacuated with oil pump and the product 
 
 distilled. The contents of the flask nearly all distilled over 
 
 0 
 
 at a constant temperature. Boiling point 137 - 140 .43 rmn. 
 
 Upon pouring the distillate out into open dish the product crys- 
 tallizes in white needles. Yield 9*3 g ( 80 per cent of the cal- 
 culated amount ). After recrystallization from ether solution 
 
 0 
 
 by the addition of petroleum ether the product softens at 49-50 
 
 o 
 
 and melts at 54 ♦ 
 
 Substance 0.4511, O.3556 : 29*01 cc. 0.09872 11 HC1( Kj elhahl 
 Calculated for C7H11O3U : N, 8. 91. Found: 8.86> 8.84. 
 
 L. 
 
 
-31- 
 
 2.0013 % dissolved in water and made up to a volume of 
 
 10.00 cc gave a rotation of -.49 in a 1 dm. tube in sodium 
 
 o 
 
 light ; -2.45 . Neither this product or the free acid 
 
 made by heating d-glutamic acid in a similar manner gives a 
 nitroso derivative when treated with hydrochloric acid and 
 sodium nitrite, sodium nitrite in glacial or 50 per cent ace- 
 tic acid (or in solution in dry ethe r when treated with amyl 
 nitrite and dry hydrogen chloride). 
 
 d-Dimethyl Glutamate Hydrochloride. 
 
 The crude ester hydrochloride was prepared exactly as des- 
 cribed for the diethyl compound, the ester hydrochloride would 
 not crystallize upon cooling and the product would not crystal- 
 lize when precipitated from chloroform solution by means of 
 ether i 
 
 Dimethyl «=<Diazoglutarate 
 
 This diazo compound was prepared from the crude amino 
 ester hydrochloride exactly as described for the diethyl ester 
 from 3 0 g. of the d-ester hydrochloride , there was obtained 
 
 f 
 
 12 g of the crude diazo ester. After vacuum distillation there 
 
 o 20 ° 
 
 was obtained 6 g of product boiling at 86 - 87 *5 nun; d 4 0 
 
 I.I83; njj 1.4730 at 20 ; Rotation in a 1 dm. tube at 22° +1.04 
 23 ^0 
 
 CcK.*] x) + *88 • The product was redistilled and 3 g of pro- 
 
 0 p o° 
 
 duct was obtained boiling at 85 - 86 ,4 mm d—~ 1.185 n-^ 
 
 1.4753' Rotation in a 1 dm. tube in sodium light at 22 +1.06; 
 22 0 9 
 
 + » 8 9 . 
 

 
 
-32- 
 
 Substance : 0,2203, 0,2091 : 29.87 cc N at 23 0 and 739 mm. 
 28.33 cc N at 22° and 740 mm. 
 
 Calculated for C 7 H 10 O 4 U 2 : N, 15*07* Found: 14.78, 14.83* 
 
 ! 
 
 Another preparation of this diazo ester was made in exactly 
 the same way except that a lower pressure was used in the dis- 
 tillation, the results were exactly the same. Eoiling point 
 o 
 
 82 - 83 0.2 mm. 
 
 d-Isopropyl Glutamate 
 
 The crude ester hydrochloride was prepared in the same 
 manner as described for the diethyl ester hydrochloride, except 
 that it was necessary to heat the reaction mixture for about 
 3 times as long. The crude ester hydrochloride would not crys- 
 tallize upon cooling, and could not be crystallized from chloro- 
 form by the addition of ether, so the free ester was liberated 
 in the usual manner and the product vacuum distilled. From 50 
 
 g of glutamic acid 'hydrochloride 22 g of product were obtained, 
 
 0 
 
 boiling at 115 - 117 0.15 mm. The product is a water, white 
 
 viscous oil. 
 
 20 ° 20 ° 
 d -40 1.023 1.4402 
 
 0 0 
 
 The rotation in a 1 dm. tube in sodium light at 22 is +5*65 
 
 2 . 2 . ® 
 d + 5*o8 . 
 
 Analysis (Kjeldahl) 
 
 Substance O. 2739 , 0 , 2853 : 11,49 cc., 11.97 cc., 0.1040 N 
 
 H 2 SO 4 
 
 Calculated for C 11 H 21 HO 4 : N, 6,06. Found: 6.11, 6.10. 
 
 d-I so propyl. Glutamate Hydro chloride 
 
 ihe ether solution of the free ester was treated with dry 
 
hydrogen chloride, and the ester hydrochloride was precipitat- 
 ed as a thick viscous oil* The ether was decanted and the re- 
 mainder of the ether and hydrochloric acid removed in vacuo 
 over sulphuric acid and sodium hydroxide* The yield was prac- J 
 tic ally quantitative. 
 
 Diisopropyl-Diazoglutarate 
 
 The preparation of this diazo ester was carried out ex- 
 actly as described for the diethyl ester, using the ester 
 hydrochloride prepared by precipitation of the free ester from 
 ether solution by dry hydrogen chloride. From 20 grams of the 
 ester hydrochloride there was obtained 6 grams of crude pro- 
 duct, the product was washed and dried as described for the 
 
 o 
 
 diethyl ester. The crude product had a rotation of + 1.24 in 
 a 1 dm* tube in sodium light. The product was tested for amino 
 nitrogen by the Van Slyke method*. 0.1084 was warmed with 504 
 acetic acid until yellow coloration was destroyed, and then 
 
 i 
 
 "gave only 0-04 cc. of, nitrogen T .?han treated in a micro. Van Slyke 
 ^machine. An attempt to distill a portion of the product results! 
 
 ;in a large amount of decomposition. 
 
 Diisopropyl o< Hydroxy Glutarate. 
 
 The remainder of the crude diazo ester prepared above was 
 shaken with 20 per cent sulphuric acid in the usual manner 
 until the 3^ellow cloor disappeared. The mixture was then ex- 
 tracted with ether, the ether layer dried over anhydrous sodium 
 sulphate, the ether evaporated off on the water bath and the 
 

 . — 
 
 
 
 
 
 
 h i 
 
 
 
 
 >- 
 
 . 
 
 ■ 
 
 
 
 V 
 
 L 
 
 
 ; 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-34- 
 
 product distilled with steam. Yield 2 grains. The product is 
 
 slightly heavier than water, n 1.4440. 1.4732 g of 
 
 product dissolved in ether volume of solution 5*00 cc., rota- 
 
 o o 24 
 
 tion in a 1 dm tube in sodium light at 24 + .33 ; [o< J -p 
 
 o 
 
 +1.12 ♦ The product gave no test for amino nitrogen when 
 tested by Van Slyke nitrous acid method. 
 
 Attempt to Prepare d-Di-n-butyl Glutamate. 
 
 Fifty grams of d-glutamic acid hydrochloride was treated 
 in the same way used for the preparation of the diisopropyl 
 ester. The product after the evaporation of the excess alcohol 
 would not crystallize, and the product was soluble in ether. 
 
 The crude product was treated with potassium carbonate and con- 
 centrated sodium hydroxide in the usual manner to obtain the 
 
 62 
 
 free amino ester and the crude product vacuum distilled. 
 
 o 
 
 Yield 20 g B.P. 151-153 at 0.2 mm. The product is a colorless, 
 very viscous sirupy liquid with a small amount of flaky mater- 
 ial floating in it. The product was redistilled and obtained 
 
 as a clear oil. The product would not crystallize when immers- 
 
 20° 20 
 
 ed in a bath of salt and ice. d 1.1101; I. 4773 . 
 
 o 32 
 
 Rotation in a 1 dm. tube in sodium light at 22° -13*75 >£°Od 
 -12.39°* 
 
 Substance 0.8499, 0.3201: 46.58, 17.62 0,0979 N KC1 
 
 ( Kj eldahl ) 
 
 Calculated for CiaHacNO*: B, 5*40* Found: N, 7*53, 7*55 
 Calculated for CeHicOsN : 7 . 56 , 
 
 The product did not react when treated with an equivalent 
 
 0 
 
 amount of hydrochloric acid and sodium nitrite at 0 . The 
 

 
 
 
 
 
-35- 
 
 product evidently is butyl 5 pyrrolidone 2 carboxylate. It 
 probably was formed during the esterification and not upon dis- 
 tillation as the crude esterification mixture after evapora- 
 tion of the excess alcohol was soluble in ether* 
 
 1-Diethyl Asparate Hydrochloride. 
 
 The crude ester hydrochloride was prepared from 1-asparag- 
 
 sa 
 
 in according to the method of Curtius and Lang and was re- 
 crystallized from chloroform solution by means of ether as 
 described for d-diethyl glutamate. From 30 g of asparagin 
 
 0 
 
 there was obtained 27 g of the ester hydrochloride. M.P. 95 * 
 Diethyl c^Diazosuccinate. 
 
 This compound was prepared from the recrystallized amino 
 ester hydrochloride according to the method of Curtius and 
 
 " 6 4 
 
 Muller . From 27 g of the ester hydrochloride there was ob- 
 tained after two distillations 7 S of product, boiling at 77“ 
 
 0 
 
 78 at 0.1 mm. 
 
 20 ° 
 
 d 4 1.139 Rotation in a 1 dm. tube in sodium light 
 
 O 0 38 o 20 
 
 at 22 - 1.40 , L^< - 1.23 hp 1.4620 
 
 The product was analyzed by the sulphuric acid method. 
 
 0 
 
 Substance 0.2106, 0.20831 26.94, 26.53 cc N at 24 and 
 742 mm. 
 
 Calculated for C8H13O4H2; 14,00. Found; 13*93* 13*87. 
 
 The product was tested for amino nitrogen by the Van Slyke 
 nitrous acid method: 0.10 cc of the diazo ester after treat- 
 
 ment with 50 per cent acetic acid until the yellow color was 
 destroyed gave only 0.02 cc of nitrogen. The diazo ester was 
 

 
 
 
 
 
 
 
 
 
 , 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 . 
 
 * 
 
 
 
 • 
 
 
 
 
 ; • 
 
 
 
 
 <• 
 
 • 
 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
-36- 
 
 treated with dilute sulphuric acid in the usual manner. 3. 0112 
 
 grams of crude material was obtained, the product was diluted 
 
 with ether to a volume of 5. 00 cc and the rotation taken in a 
 
 0 024 0 
 
 1 dm. tube in sodium light at 24 ; cx - 0.59 “ 0*98 . 
 
 cK>Amino n-Caproic Acid ( Nor-leucine ). This amino acid was 
 
 31 »5B, 8fi 
 
 prepared by the methods previouslu used and resolved by 
 
 'TJ7 j 
 
 means of the brucine salt of the formal derivative • The d. 
 
 e b 
 
 and 1 ethyl esters were prepared by Fischer's method and the 
 
 37 
 
 ester hydrochlorides prepared by the method of Noyes and Marvel. 
 
 Preparation of Optically Active Diazo Esters from the d- and 
 1-Ester Hydrochlorides of cKAmino-n-Caproic Acid* 
 
 The diazo esters from these esters have been prepared by 
 
 89 
 
 Noyes and Marvel and found to be inactive, using substantial- 
 ly the same method, except using 10 per cent sulphuric acid 
 instead of glacial acetic acid and lower pressures for the dis- 
 tillation of the optically active diazo esters were prepared. 
 
 The crude diazo esters obtained were purified in the same manner 
 as already described for diethyl diazo glutarate, omitting the 
 
 treatment with sodium methylate however. Using 20 grams of the 
 
 23 
 
 1-ester hydrochloride - 7*27 ) 4*6 of crude diazo ester 
 
 were obtained which after one vacuum distillation (boiling 
 
 0 0 
 
 point *35 mm) had a specific rotation of -I .89 . After 
 
 0 
 
 a second distillation 2 g. were obtained boiling 54-55 .35 mm: 
 
 Tex} -1.89, n|° 1.4535 d f 2- .972. 
 
 The product was again vacuum distilled and 1.1 g of product 
 
 0 0 
 
 was obtained boiling 54 - 55 .35 mm. 
 
“ 37 - 
 
 30 
 
 np 1*4543 d^o .974 
 
 1.0112 g dissolved in dry ether. Volume of solution 2,00 c. 
 
 0 . r 24 
 
 Rotation in a 1 dm tube in sodium light at 24 - • 97>t 0< J r 
 
 V 1 
 
 - 1 . 92 . 
 
 Analysis (sulphuric acid method) 
 
 Substance O. 1567 , 0.2243: 24.19 cc N at 23 ° and 745 mm. 
 33.50 cc. U at 24° and 745 mm. 
 
 Calculated for C 8 H 14 O 3 U 2 : N, 16.47* Found: 16.27, 16.33* 
 
 The product gave no test for amino nitrogen when tested 
 
 by the Van Slyke and nitrous acid method in the usual way. 
 
 When the product was hydrolysed with dilute sulphuric acid as 
 
 described for diethyl diazo glutarate, the hydrolyzed product 
 
 was levorotatory and upon saponification a levorotatory sodium 
 
 salt was obtained. The aqueous solution was acidified and 
 
 extracted with ether. The ether extract was also levorotatory. 
 
 From 12 g of the d-ester hydrochloride L«=<J ^ + 5.48 
 
 there was obtained 3 grams of the crude diazo ester, which 
 
 0 
 
 after vacuum distillation (B.P. 53-55 at O .35 mm. ) had a 
 
 0 
 
 rotation in a 1 dm. tube of +1.79 • After a second distilla- 
 
 0 
 
 tion 1.4 grams of product was obtained boiling at 54*53 *35 
 
 a o '20 
 
 mm.. n^ 1.453 g d^: O. 97 ; 1.1813 g were dissolved in 
 
 ether, volume of solution 2.00 cc. rotation in a 1 dm, tube in 
 
 3 3 O 
 
 sodium light at 23 ° 1.09 . + 1.84 . 
 
 Substance 0.1843, 0.1663* 26.82, 24.16 cc. H at 24 and 
 741 mm. 
 
 Calculated for CsHi^OsHa : N, 16.47. Found 15*82, 15 . 79 . j 
 The product was hydrolyzed by dilute sulphuric acid in the 
 manner described for diethyl diazoglutatat e, the ether solution 
 

 
 
 
 
 V 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
-38- 
 
 of the hydrolysed product was dextrorotatory. Volume of ether 
 
 solution 3.00 cc rotation in a 1 dm. tube in sodium light 
 
 + 0.22; the ether was evaporated, the residue weighed 0.9211 
 
 0 
 
 grams px"] - + 1.19 * 
 
 The crude hydroxy ester was saponified. When this saponi- 
 fication mixture was acidified and extracted with ether, the 
 ether extract was also dextrorotatory. 
 
 Amino Isosaproic Acid (Leucine). This amino acid was 
 
 / bo « 
 
 prepared and resolved by the methods given in the literature 
 
 ei 
 
 The d and 1 esters were prepared by Fischer's method, and 
 the ester hydrochlorides perpared by dissolving the free ester 
 in ether and passing in -dry hydrogen chloride. Ten grams of 
 the levo leucine ([eKl-n -13*47° in 20 per cent EC1 ) gave 9*5 
 grams of ester boiling at 84-83° at 13 mm. ° 0 . 92 . 
 
 Rotation in a 1 dm tube in sodium light at 22° - 10.93* ;[<* ? D j: 
 - 11.41°. The yield of the ester hydrochloride was 11. 3 grams. 
 
 Ethyl Diazoisocaproate. 
 
 The ester hydrochloride was diazotized in the usual man- j 
 
 ner. From 11. 5 grams of the hydrochloride there was obtained 
 
 0 
 
 2.0 grams of the diazo ester boiling at 47-30 at 0.3 mm. 
 
 20° 20 
 
 a ^0 0.938 n c 1.4310; 1.8360 grams dissolved in ether 
 
 volume of solution 5*00 cc. Rotation in a 1 dm. tube in sodium 
 0 
 
 light -.36 ;ro<] D - 1 . 32 °^ The product was redistilled and 1.2 
 
 0 20 
 
 grams were obtained boiling at 49-30 at 0.30 mm. d 0 . 961 : 
 
 30 
 
 n D 1.4333* 
 

 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 - 
 
 . 
 
- 39 - 
 
 I.II 38 grams dissolved in ether, volume of solution 3*00 
 
 0 o 
 
 cc; Rotation in a 1 dm tube in sodium light at 24 -0.34 ; 
 
 0 
 
 -1.32 . The product was analyzed by the sulphuric 
 
 
 acid method. 
 
 Substance 0.1438, 0.1318,* 21.33, 22 . 
 7*41 mm. 
 
 Calculated for CaHi-iOaila: N, 16,47. 
 
 15 * 97 * 
 
 0 
 
 30 cc. N at 24 and 
 Round II, 16 . 12 , 
 

 - - 
 
 , 
 
 
 
 
 
 
 
 ' 
 
 
 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
- 40 - 
 
 IV SUMJiARY 
 
 1* Diazo esters were prepared from the' following amino 
 ester hydrochlorides by the Curtius method: 
 
 d-Diethyl Glutamate Hydrochloride, d-Dimethyl glutamate 
 hydrochloride, 
 
 1-ethyl cxamino-n-caproate hydrochloride, d-ethyl <=<amino- 
 n-caproate hydrochloride. 
 
 l-ethylc=<aminoisocaproate hydrochloride, 1-diethyl asparate 
 
 % 
 
 hydrochloride. 
 
 2. The diazo esters prepared from all of the above amino 
 esters were found to be optically active in the same sense as 
 the original amino esters. 
 
 3* When the above diazo esters were decomposed by dilute 
 acids the products are optically active, in the same sense 
 and to a similar degree. 
 
 4. The products obtained by the treatment of diazo esters 
 with dilute acids are strongly unsaturated, indicating the 
 presence of considerable amounts of the corresponding unsatu- 
 rated esters.. 
 
 When the amino esters are treated with nitrous acid 
 under conditions by which the diazo esters are decomposed 
 without being isolated the products are optically active, in 
 the same sense but to a slightly higher degree than those ob- 
 tained from the decomposition of the purified diazo esters. 
 
 6. The products obtained under these conditions have ex- 
 actly the same physical constants as those obtained by the de- 
 

 
 
 
 
 
 
 
 
 i 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 •r 
 
 
 
 
 
 
-41- 
 
 composition oi the purified diaso ester, except - or a slightly 
 higher optical activity* 
 
 7* Vacuum distillation of the hydrolysis products of di- 
 ethyl diazoglut arate decreases the activity on the first dis- 
 tillation but subsequent distillation causes no further change 
 in activity. Analysis density and molecular refraction indi- 
 cates that, the product is a constant boiling mixture of the 
 unsaturated ester and ester lactone* 
 
 5* The produce obtained by steam distillation shows exact- 
 ly the same properties and constants* 
 
 9* Upon saponification of the hydrolysis products of the 
 diazo esters optically active sodium salts are obtained which 
 rotate in the same direction as the original amino acids* 
 
 10* When tne sodium salts are acidified and the mixture ex- 
 tracted with ether the ether extract is optically active in the 
 same sense as the original amino acids* 
 
 11* Upon reduction with aluminium amalgam in moist ether 
 solution followed by acid hydrolysis diethylo<diazotf lutarate 7 
 gives glutamic acid with a rotation corresponding to approxi- 
 mately thirteen per cent of the active acid. 
 
 12* Impure diisopropyl ok diazoglutarhte was prepared which 
 was optically active but it was largely decomposed upon distil- 
 lation. 
 
 13* Impure ethyl and methyiydiazovalerates were prepared 
 from the lactam of y amino valeric acid by Oppe*s method*. 
 
 14. An attempt to prepare d-dibutyl glutamate by the usual 
 

 
 
 
 * s > 
 
 . 
 
 , 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 I 
 
 
 
 
 
 
-42- 
 
 method resulted in the production of butyl 5 pyrrolidone 2 
 carboxylate(p<? -12. 39°* 
 
 13. It appears probable that there are two forms of diazo 
 ester, the one optically active and the other inactive, the 
 active form beiiig decomposed by dilute acids with the formation 
 of hydroxy esters and being reducible to the active amino acid* 
 The inactive form decomposing with the formation of the unsat- 
 urated ester and giving the inactive amino acid upon reduction. 
 
 16. It seems unlikely that diazo compounds are intermedi- 
 ate products in the formation of hydroxy acids when free amino 
 acids are treated with nitrous acid. 
 
 

 * 
 
 
 
 I 
 
 V, 
 
 
—43“ 
 
 V BIBLIOGRAPHY 
 
 1* Leverie and Mikeska, J. Biol* Chem., 4 %, 593 (1921) 
 
 2. Noj^es and Marvel, J. Am. Chem. Soc., £ 2 , 2259 (192 0) 
 
 „ r 
 
 3. Schiff and Meissen, C-azz. 3J., 171 ( l88l ) : Ber. 1375(1881 
 
 4. Curtius, Ber., l£, 2230 ( 1883 ) 
 
 5* Curtius, J. prakt. Chem* (2)^8, 394 ( 1888 ) 
 
 6. Curtius, J. prakt. Chem. 38 . 440 ( 1888 ) 
 
 7. Darapsky and Prabhakar, Ber. 42, 1654 (1912 ) 
 
 8. Staudinger, Ber. 49, 1884 (1916): 
 
 Staudinger, Becker and Hirzel, Ber. 4 %, 1978 (1916). 
 
 9* Staudinger, Gaule and Siegwart, Hel. Chem. Acta., IV 212-217 
 (1921) 
 
 10. Staudinger, Ber. 4$, 1884-97 (1916). 
 
 11. Curtius, Ber. 1&,~ 2230 (1883) 
 
 12. V. Perchmann, Ber. 22, 1889, (1894); 28, 855 (1895 )* 
 
 13. Oppe, Ber.. 44, 1095 (1913 ) 
 
 14. Staudinger, Eer.. 2198 ( 1911 ) 
 
 15* Ritthausen, J. pr. Chem., ( 1 ) 105 . 239 (1868); (2 ) 2» 354 
 ( 1872 ) 
 
 16. Pischer, Ber. 45., 2447 (1912) 
 
 17% Pischer, Ber. 4£, 1332 (1911). 
 
 18. Curtius, J. prakt. Chem., (2)2°, 477 ( 1888 ) 
 
 19. Koyes and Marvel, J. Am. Chem. Soc., 4£, 2262 (1920) 
 
 20. Staudinger, Ber. 4£ 1884; £9, 1978 (1916) 
 
 21. Ritthausen, J. prakt. Chem. ( 1 ) 2£2» 239 ( 1868 ); (2)2, 554 
 ( 1872 ) 
 
 22. Walden, Ber. 2&, 2?22 (1895); . 
 
 t 
 
 23. Pischer, Ber, H, 2897 (1908^22, 2020 (1912 ) ' 
 

 . 
 
 
 4 
 
 
 
 
-44— 
 
 24. Scheibler and Wheeler, Ber. 44, 2684 (1911) 
 
 2^* Fischer, Ber. 2., 2447 (1912) 
 
 26. Fischer and Weibhbold, Ber. .4^, 1294 (1908): 
 
 27* Noyes and Marvel, J. Am. Chem. Soc., ^2, 2268 (1920) 
 
 28* Levene, J. Biol. Chem., .21, 348 (1919) 
 
 29. levene and Mikeska, J , Biol. Chem. 43., 993 (1921) 
 
 30. Walden, Ber. 28, 2772 (1899 ) 
 
 31. Fischer and Groh, Ann. 385 . 363“372 (1911) 
 
 32. Taf el, Eer., jL2, 2414 ( 1886 ) 
 
 33* Curtius, Darapsky and Mttller, Ber., 4J*, 3140, 3161 (1908) 
 
 34. Hantzsch and Lehmann, Eer. ^4, 2506 (1901) 
 
 35. Fischer, Ber. 34, 433 (1901) 
 
 36. Foreman, Biochem. J., j£ 9 378 (1919) 
 
 37 » Noyes and Marvel, J. Am. Chem. Soc., 42, 2270 (1920) 
 
 38. Curtius, J. prakt. Chem., (2)^£, 4l8 ( 1888 ) 
 
 39» Curtius, Darapsky, and Miller, Ber. 4^, 3140, 3161 (1908) 
 
 40. Hantzsch and Lehmann,, Ber. 2506 ( 1901 ) 
 
 41. Fischer, Ber. 34, 433 (1901) 
 
 42. Abderhalden, Zeitsch, Physiol. Chem., XL* 79 (1912) 
 
 43. Fischer, Ber, £±, 1332 (1911) 
 
 44. Curtius and Koch, Ber. JX* 2460 (887) 
 
 49* Fischer and Warburg, Ber. 2447 (1912) 
 
 46. Schneider, Ann. 207 Zb 7 (l88l); 
 
 47* Thomsen, J. prakt. Chem. (2) 33., 149 (1887)$ Ber. Xl» 441 ( l8o2 ) 
 
 48. Stubbs, J. Chem. Soc », T 2263 (1911) 
 
 49. Clough, J. Chem. Soc. T 326 ( 1918 ) 
 
 50. Ber. 28, 1325 (1893) 
 

 
 
 
 
 
 . 
 
 
 ' 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 
 
 : 
 
 
 
 
 
 
 
 
 
 
-45- 
 
 51. Fischer and Bolhner, Ber., 14, 133 2 ( 1911 ) 
 
 52. Fischer, Ber. 14, 438 (1901) 
 
 33 . Curtius and Lang, J. prakt. Chem. (2) 44 . 564 
 54. Curtius and Muller, Ber. 12., 1261 (1904) 
 
 55* Z. physiol. Chim. 84 , 454 ( 1913 ) 
 
 56 . J. Am. Chem. Soc., 42 . 320 (1920) 
 
 57. Ann. 362, 113 (1908) 
 
 58 . Fischer, Ber. 14, 433 (1901) 
 
 59* Noyes and Marvel, J. Am. Chem. Soc., 42, 2272 (1920) 
 
 60. Fischer and Warburg, Eer. 38 , 3997 (1905) 
 
 61. Fischer, Ber. 14, 433 (1901) 
 
VITA 
 
 The writer was born near Carlinville, Illinois, July 2, 
 l894* He entered Blackburn College in the fall of 1912, which 
 he attended the ensuing year,. In the fall of 1913 he entered 
 the University of Illinois and graduated with the degree of 
 Bachelor of Science in Chemical Engineering in 1917* He began 
 his graduate work at the University of Illinois in June, 1917 > 
 while employed as full time assistant in Animal Nutrition. In 
 June, 1918, he resigned his position in the University to take 
 up war work with the Bureau of Aircraft Production, doing re- 
 search work on the production of isopropyl alcohol and the oxi- 
 dation of it to acetone, together with other minor problems. 
 
 In January, 1919> he reentered the Graduate School of the Uni- 
 versity of Illinois and graduated with the degree of master of 
 Science in 1920. While at the University of Illinois he held 
 the following appointments : - full-time Assistant in Animal 
 Nutrition, 1917“l8, Assistant in Chemistry, January, 1919 to 
 June, 1920, Graduate Assistant in Chemistry, 1920-21, 1921-22. 
 

 
 
 
 
 
 
 
 
 
 
 
 * • * 
 I 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 . 
 
 
 
 
 
 
 I 
 
 
 
 . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 . 
 
 
 .