214 PROCEEDINGS OF THE AMERICAN ACADEMY 



m 



Metahromhe7izylbromide (CfR^Br.CH.Br.) was made from meta- 

 bromtoluol, prepared by Wroblevsky's * method (compare also 

 Grete t)j as follows : 30 gr. of the mixture of para- and orthoacettoluid, 

 obtained as a secondary product in Wroblevsky's process for purifying 

 orthotoluidin, previously reduced to a granular condition by crystalli- 

 zation from boiling-water, were suspended in cold water, and 45 gr. 

 of bromine dissolved in water added in small portions at a time^ shak- 

 ing until the yellow color disappeared after each addition ; the acetyl 

 group was removed from the metabromacettoluid thus obtained by 

 boiling with fuming hydrochloric acid in a flask with a return-cooler ; 

 the base, set free by an alkali, was dissolved in portions of 10 gr. at 

 a time in absolute alcohol, and the amido group replaced by hydro- 

 gen by Griess's reaction ; the alcohol was then partly distilled off on 

 the water-bath ; the residue distilled with steam, dried, and rectified, the 

 portion passing over from 179° to 185°, being collected. To convert 

 this into metabrombenzylbromide, 10 gr. of it were heated to boiling, 

 and treated with 12 gr. of bromine in the way described under para- 

 brombenzylbromide (see page 212) ; the slight excess of bromine over 

 the molecular proportion was taken to allow for the loss in the pro- 

 cess ; the metabromtoluol took up the bromine somewhat more slowly 

 than the parabromtoluol. The liquid left after the brorairing was fin- 

 ished, was distilled in a current of the vapor from hydrobromic acid 

 (boiling-point 125°), prepared according to Naumann,]: until a con- 

 siderable portion had passed over : the flask containing the substance 

 was not heated for fear of decomposition. The hydrobromic acid 

 vapor cannot be replaced by steam ; as under these conditions some of 

 the brombenzylalcohol might be foi-med, although I am inclined to 

 think that this reaction woul 1 take place much less readily here than 

 it does in the case of the parabrombenzylbromide (compare page 212). 

 The residue left in the flask was transferred to a funnel-tube, closed 

 with a rubber stopper on a glass rod, and surrounded with ice. If 

 the distillation had been carried on long enough, nearly the whole of 

 the oil solidified to a dark, j^asty mass. The stopper was then removed, 

 and the bi'own oil sucked out as completely as possible by means of 

 the Bunsen pump. The white scales left on the funnel were boiled 

 with a small quantity of alcohol ; the clear solution poured off from the 

 undissolved oil and cooled in a corked flask. As soon as no more oil was 



* Wroblevsky, Ann. Chem. Pharm., 168, p. 153. 



t Grete, ib., 177, p. 231. 



I Naumann, Ber. D. Ch. G., 1876, p. 1574. 



