306 



PROCEEDINGS OF THE AMERICAN ACADEMY 



The addition product formed then loses two molecules of water, going 

 over into the furfuran derivative, 



CH 



CO2C2II5 



CO.Calls. 



Benzofarfuran Derivatives from Quinone and Acetoacetic Ether. 



Von Pechraann * describes a condensation product obtained from 

 quinone and acetoacetic ether by means of alcoholic chloride of zinc. 

 He gives it the formula CisHigOe, and, as he states, it is formed 

 according to the following equation : 



C6H4O2 + 2C6H10O3 = CiellicOo + H2O + CJloO. 



From the product CisHigOe, he obtained further, by saponification 

 with alcoholic potash, a dibasic acid, C14H12OC. 



Since v. Pechmann says that he does not intend to study the product 

 obtained any further, I have taken up the investigation of these sub- 

 stances, especially since the behavior of the compound CieHigOg is 

 very similar to the benzofurfuran derivatives obtained from chloranil, 

 and it therefore seemed probable that it possessed a similar consti- 

 tution. The formulae given by him for the above products are de- 

 duced from the mean result of a number of analyses. It is difficult, 

 for instance, to see how from a neutral substance, CigHieOe, by sa- 

 ponification, a dibasic acid, ChRi^Oq, can be formed, since the former 

 substance is not likely to contain methoxy groups. The study of 

 these substances soon showed that the empyrieal formulae given to the 

 condensation product as well as the dibasic ncid were incorrect. 



The reaction between quinone and acetoacetic ether really takes 

 place according to the following equation : 



I. CCII4O2 + 2 CcIIioOa = CisTIisOe + 2 H,0 + 2 II ; 



the two hydrogen atoms are used up in converting a molecule of qui- 

 none into hydroquinone : 



IT. C6H4O2 -f 2 n = CJI4 (011)2. 



* Ber. d. chem. Ges., XXI. 3005. 



