CONTRIBUTIONS FROM THE CHEMICAL LABORATORY 

 OF HARVARD COLLEGE. 



ON CERTAIN DERIVATIVES OF ORTHOBENZOQUINONE.* 



By C. Lokixg Jackson and Waldemar Koch. 



Presented May 9, 1900. Received October 17, 1900. 



Attempts to prepare the orthobenzoquinone 



have been mentioned, so far as we can find, in only two papers. The first 

 is that by Zincke,t in which he describes tetrabroniorthoquinone and 

 tetrachlororthoquinone, but says that a number of attempts to make the 

 unsubstituted orthoquinone have failed to produce the desired result. 

 The second is by Hinsberg and Himmelschein,| who obtained ortho- 

 dioxydiphenylsulphone by the action of potassic dichromate on a mixture 

 of pyrocatechine and benzolsulphinic acid, and draw the inference that 

 the formation of this substance probably was preceded by the formation 

 of orthoquinone. They add that all their experiments to isolate ortho- 

 quinone have failed because of its strong tendency to condensation and 

 polymerization. 



It seemed to us that one probable cause of the ill success of these 

 experiments was the sensitiveness of the orthoquinone to oxidizing agents ; 

 this view was confirmed by the observations of Cousin, § that trichlorpy- 

 rocatechine and dibrompyrocatechine give only red resinous products with 



* The work described in this paper formed part of a thesis presented to the 

 Faculty of Arts and Sciences of Harvard University for the Degree of Doctor of 

 Philosophy by Waldemar Koch. 



t Ber. d. chem. Ges., XX. 1776 (1887). 



1 Ber. d. chem. Ges., XXIX. 2025 (1896). 



§ Annates de Chiui. et de Phys., [7] XIII. 485. 



