188 PROCEEDINGS OF THE AMERICAN ACADEMY 



XIII. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OP 



HARVARD COLLEGE. 



ON SUBSTITUTED PYROMUCIC ACIDS. 



SECOND PAPER. 



By Henry B. Hill and Arthur W. Palmer. 



Presented March 14, 1888. 



ON SULPHOPYROMUCIC ACIDS* 



Pyromucic acid shows in many of its reactions so close an analogy 

 to benzoic acid that a study of its behavior toward concentrated sul- 

 phuric acid could hardly fail to yield interesting results. In 1860 

 Schwanert t prepared a sulphopyromucic acid by distilling sulphuric 

 anhydride slowly over powdered pyromucic acid. The barium salt 

 was said to be not distinctly crystalline, and its composition was es- 

 tablished by a single determination of barium in the salt dried at 150°. 

 With the exception of the brief notice by Schwanert, we have been 

 able to find no mention of furfuran derivatives containing the sulpho- 

 group. We have found that a sulphopyromucic acid is formed with- 

 out difficulty when pyromucic acid is dissolved in fuming sulphuric 

 acid, and that a second sulphonic acid may readily be made by indirect 

 methods. We have also prepared and studied several derivatives of 

 these sulphonic acids containing bromine, and have succeeded in estab- 

 lishing the constitution of these various products. 



8-Sulphopyromucic Acid. 



If dry pyromucic acid is slowly added to fuming sulphuric acid (Sp. 

 Gr.l.95),it dissolves without serious discoloration, and in a short 



* A part of the work described in the following paper was presented in the 

 form of a thesis to the Academic Council of Harvard University in May, 1886, 

 by Arthur W. Palmer, then candidate for the degree of Doctor of Science. 



t Annalen d. Chem. u. Pharm., cxvi. 268. 



