308 



PKOCEEDINGS OF THE AMERICAN ACADEMY 



I give here, for convenience' sake, the properties of the substance.* 

 " Coloi'less needles, melting at 184°. Insoluble in water or alkalies, 

 and soluble in chloroform and boiling acetic acid. The solution in 

 concentrated sulphuric acid turns deep blue on warming. Bromine 

 reacts, forming a crystalline derivative. Phenylhydrazin, benzoyl 

 chloride, and hydriodic acid have no action on the substance." 



The proof that the compound CisHigOe has the constitution above 

 given is as follows : chlorine converts it into a disubstitution prod- 

 uct C18H16CI2O6, which is identical with ^-dichlorbenzo-jo-difurfuran 

 a-dimethyl /3-dicarboxylic ether, 



O CI 



CO2C2H5, 



CH, 



HsC.,0,C 



already described and obtained from chloranil. 



The substance is dissolved in acetic acid, and chlorine is passed into 

 the solution for several hours in the sunlight, until a portion treated 

 with zinc dust gives on addition of water a crystalline precipitate melt- 

 ing from 155-160°, when the rest of the solution is treated in the 

 same manner. By repeated crystallization from acetic acid (95%), 

 the crude product was finally converted into a substance which melts 

 constant at 175°, and crystallizes in long transparent needles iden- 

 tical in every respect with the p-dichlorbenzodifurfuran derivative 

 CisHieCloOe described above. This was also confirmed by a halogen 

 determination. 



0.2138 gram substance dried at 120° gave 0.1499 gram AgCl (Carius). 

 CI 



Theory for CigHioCUOg. 



17.79 



Found. 



17.35 



The substitution of the two hydrogen atoms of CigHigOo is un- 

 doubtedly preceded by the formation of an addition product, just as 

 CisHjcCloOe gives, when treated with chlorine, an oily addition product 

 as before mentioned, but the cldorine in these addition products is 

 easily taken out by zinc dust and acetic acid. 



These results prove conclusively the constitution of the condensa- 

 tion product CigHifjOfi; the constitution of the dibasic acid Ci4HioOe 



* Ber. d. chem. Ges., loc. cit. 



