306 



PROCEEDINGS OF THE AMERICAN ACADEMY 



XVII. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



RESEARCHES ON THE SUBSTITUTED BENZYL COM- 

 POUNDS. 



FIFTH PAPER. 



PARACHLORBENZYL COMPOUNDS. 



By C. Loring Jackson and J. Fleming White. 



Presented March 12, 1879. 



In the fourth paper of this series the necessity of a revision of all 

 the so-called parachlorbenzyl compounds was pointed out, and the 

 results were described, which had been obtained from the investigation 

 of some of them by Mr. A. W. Field and one of us. This work is 

 now finished, and we have the honor of laying before the Academy a 

 description of the preparation and properties of the remaining f>ara- 

 chlorbenzyl compounds, which have been heretofore made in an im- 

 pure state, and also of a few related substances not as- yet described. 



Parachlorbenzylbromide melting-point, 48^° (made from pure para- 

 toluidine), was used as the starting-point for these compounds, and 

 therefore they cannot contain the isomeric impurities which caused 

 the mistakes of our predecessors. 



A comparison, in tabular form, of our more important results with 

 the earlier ones, will be found at the end of the paper. 



Parachlorbenzylsulphoacid, C G H 4 C1CH 2 S0 3 H. 



This substance was first studied by Bohler,* whose paper, published 

 in 1869, contains a description of the preparation of the potassium 

 salt by heating chlorbenzylchloride with neutral potassic sulphite. It 

 was, in fact, one of the papers coming from Strecker's laboratory to 

 illustrate his general method of making sulphoacids,f first announced 



* Bohler, Ann. Chem. Pharm. 154, p. 56. 

 t Strecker, Ann. Chem. Pharm. 148, p. 90. 



