JOURNAL OF CHEMICAL EDUCATION
PETER GRIESS AND THE PHENYLENE DIAMINES MANNING A. SMITH , Bucknell University, Lewisburg, Pennsylvania WILLIAM R. GOWERHazleton, Pennsylvania
INTHE determination of the structure of the isomeric disubstituted benzenes, the work of Korner on the dibromobenzenes and Griess on the phenylene diamines are frequently cited. Wheland (1) has a rather complete discussion of Korner's work. Essentially, Korner nitrated the dibromobenzenes and inferred the structures from the number of isomers obtained in each case. It is generally believed that Griess prepared the three phenylene diamines melting a t 6 3 O , 9Q0,' and 140°C. by isolating the six isomeric diaminobenzoic The modern accepted value is 102".
acids and decarboxylating them. As shown in Figure 1,such a procedure would lead to the correct stmctures. The diamine derived from three such acids would have to be the meta isomer. On the other hand, only two of the acids would yieid the ortho diamine. Finally, only one diaminobenzolc acid could possibly yield the para isomer. An assignment in our class in chemical literature led to the discovery that Griess had not actually isolated and decarboxylated the six diaminobenzoic acids. Rather he had used both the dinitro and diaminobenzoic
177
APRIL, 1952
time. It remained for Wurster and Ambuhl (5) to show that the barium salt of this acid yielded a phenylene diamine (m. p. 63'C.) on heating. The new dinitrobenzoic acid isolated by Griess (8) when he nitrated o-nitrobenzoic acid also melted a t 20Z°C. It is reasonable to suspect that he first helieved this to be Cahours' acid. However, if this HP 99. belief ever existed, it was quickly dispelled when he COOH found that the acid's behavior towards reducing agents differed markedly from Cabours' compound. The new acid yielded the phenylene diamine melting a t 63°C. directly, decarboxylation taking place during the reduction. The third dinitrobenzoic acid, melting a t 17Q°C., was also found by Griess in his nitration mixture. It had first been discovered by Tiemaun and Judson (IS) acids. In the course of nitrating o-nitrobenzoic acid, a few years earlier when they oxidized dinitrotoluene. he isolated, among other things, two dinitrobenzoic When Griess reduced this acid, it also was decarboxyacids (2). One of the acids was a new compound. lated and gave the phenylene diamine melting a t 63'C. When he reduced these with tin aud hydrochloric acid, both acids were decarboxylated as well as reduced. The same phenylene diamine was produced in both cases and it melted a t 63'C. Since this diamine had already been prepared from a third diiitrobenzoic acid (3,4,5), it was clearly mphenylenediamine. With the problem of the m t a isomer solved, the previous work of Griess with diaminobenzoic acids (6) served to establish the structure of the other two diamines. The phenylene diamine meltmg at 9Q°C. had to be o-phenylene diamine because he bad prepared it by decarboxylating two different diaminobenzoic acids. The third isomer, melting a t 140°C., bad to be the para compound and be had prepared it from a single diaminobenzoic acid. We did not attempt to determine precisely how this minor misconception concerning Griess's work first crept into chemistry texts. However, a cursory examination of some of the older texts which happened to be available to us revealed some thmgs of interest. In the second edition of his text (1880), von Richter wrote These reactions with the appropriate formulas are that "researches on the six isomeric dinitro or diamino summarized in Figure 2. benzoic acids" led to the stmctures of the phenylene diamines (7). Later editions of his book make no LITERATURE CITED mention of the dinitrobenzoic acids. As early as 1893 (1) WHELAND,G. W., "Advanced Organic Chemistry," 2nd ed., John Wiley &Sons, Inc., New York, 1949, p. 112-13. Bernthsen's text was reporting Griess as having decarboxylated six diaminobenzoic acids (8). In any (2) GRIESS,PETER,Ber., 7, 12254 (1874). (3) CAHOURS, A,, Ann. chin. et phys., (31 2 5 , 3 0 4 (1849). case that is the version generally reported in our modem (4) VOIT,C., Ann., 99, 106-7 (1856). texts (9,lO). (5) WURSTER, C.,AND G. AMRUHL, Ber., 7, 214 (1874). The three dinitrobenzoic acids related to mphenylene (6) GRIESS,PETER,B e . , 5, 201-3 (1872). V., "Chemie der kohlenstoff Verbindungen," diamine (m. p. 63°C.) are of some interest. The oldest (7) YON RICHTER, 2nd ed., F. Cohen & Sohn, Bonn, 1880, p. 493. of the three acids was first prepared by Cahours (3) (8) BERNTHSEN, A,, "Kuraes Lehrhuch der organisohen in 1847. I t melted a t 20Z°C. Voit (4), and later Chemie," 4th ed., F. Wieweg & Sohn, Braunschweig, Gerdeman (Il), reduced this to a diaminobenzoic acid. 1893, p. 328. In his studies on the decarboxylation of the diamino- (9) FIESEE,L. F., AND M. FIESER,"Organic Chemistry," 2nd ed., D. C. Heath & Co., Boston, 1950, p. 555. benzoic acids, Griess (12) reported that this acid did (10) WHELAND, G. W.,zbid.,p. 114. not yield a phenylene diamine when subjected to a (11) GERDEMAI~, F.,Z. Chem., 1865,51. dry distillation. This was in marked contrast to the (12) GRIESS,PETER,J. prakt. Chern., [2] 5,243 (1872). other diaminobenzoic acids he had been studying a t the (13) TIEMANN,F., AND W. E. JUDSON,B e . , 3,223 (1870).
0"
