216 PROCEEDINGS OP THE AMERICAN ACADEMY 



pound from the mixture prepared by adding bromine to cooled toluol, 

 I decided to insure a perfectly pure substance as my starting-point, by 

 making the orthobi'omtoluol from orthotoluidin. The first method 

 employed for purifying the orthotoluidin was that of Wroblevsky,* 

 by boiling crude toluidin sixteen hours with glacial acetic acid ; but all 

 the samples obtained by this process contained traces of paratoluidin. 

 After I had convinced myself by experiment that the methods of 

 Rosenstiehl,t by treating the oxalates with ether ; and of Beilstein 

 and Kuhlberg,J by precipitating an acetic acid solution of acettoluid 

 with water, — were almost impracticable for large quantities, I tried the 

 method of Schad,§ recommended by Kekule,|| which depends on the 

 crystallization of the nitrates and chlorides, and in this way succeeded in 

 obtaining a liquid toluidin which with acetylchloride gave an acet- 

 toluid melting after one recrystallization from boiling-water at 107°. 

 As some previous attempts to convert orthotoluidin into orthobromto- 

 luol by the usual method through the diazoperbromide had given me as 

 unsatisfactory a yield as that obtained by Wroblevsky,!! I treated this 

 according to a new modification of the process of Hiibner and Majert** 

 for preparing parachlortoluol, which I had found to work admirably 

 in making that substance. This modification was suggested by Victor 

 Meyer's ft method of applying Griess's reaction, and consisted in dis- 

 solving 20 gr. of the orthotoluidin in an excess of hydrobromic 

 acid (boiling-point 125°, prepared according to Naumann t|); the pasty 

 mass was then treated with somewhat more than the calculated amount 

 of solid potassic nitrite, which was thrown in in small portions at a 

 time, the fiask being corked after each addition, and shaken until all 

 the red fumes were absorbed ; after the last portion of nitrite had 

 been added, the greater part of the liquid was distilled off, and the resi- 

 due then treated again in the same way. The distillate consisted of 

 dilute hydrobromic acid and a heavy oily liquid which was separated 

 with a drop-funnel, washed with potassic hydrate solution until the odor 

 of kresole was removed, then with water, and finally dried and rectified ; 

 in this way 40 grammes of orthotoluidin gave 29 grammes of crude 



* Wroblevsky, Ann. Chem. Pharra., 168, p. 162. 



t Rosenstiehl, Zeitschr. Chem., 1868, p. 557, 666. 



t Beilstein, Ann. Chem. Pharm., 156, p. 75. 



§ Schad, Ber. D. Ch. G., 1873, p. 1361. 



II Kekule, Ber. D. Ch. G., 1874, p. 1006. 

 IF Wroblevsky, Ann. Chem. Pharm., 168, p. 171. 

 ** Hiibner and Majert, Ber. D. Ch. G., 1873, p. 794. 

 tl V. Meyer, Ber. D. Ch. G., 1875, p. 1074, note. 

 tt Namnann, Ber. D. Ch. G., 1876, p. 1574. 



