OF ARTS AND SCIENCES. 



309 



obtained from it by means of alcoholic potash necessarily follows ; it 

 is a benzo-j9-difurfuran a-dimethyl jS-dicarboxylic acid, 



O 



IlaC 



HOoC 



H 



H 



CO.,H 



CH„ 



O 



p-Oxyhenzofurfuran a-dimethyl ^-carboxylic Ether, 

 H O 



H; 



no 



CH« 



CO2C2H5. 



H 



The above alcoholic chloride of zinc mother liquors, from which the 

 product CisHigOs has been removed, always contains hydroquinone 

 and a furfuran derivative, C12H12O4, besides acetoacetic ether. The 

 hydroquinone was isolated^ after driving off the alcohol, by taking up 

 water and extracting the aqueous solution with ether. The condensa- 

 tion product C12H12O4 is obtained by allowing the alcoholic mother 

 liquors to evaporate spontaneously, when it separates out in pearly 

 scales. It is formed from quinone and acetoacetic ether according to 

 the following equation : 



CeH,02 + CeHioOs = C12H12O4 + H2O. 



The best yield (50% of quinone taken) is therefore obtained by 

 heating quinone (1 molecule) with a molecule of acetoacetic ether in 

 the presence of alcoholic zinc chloride. After filtering off the insoluble 

 product CigHigOc, which is invariably formed, the filtrate is allowed 

 to evaporate in the air, and the pearly scales which separate out are 

 brought on porous plates and washed with water. Recrystallized 

 twice from petrolic ether (bpt. 70-80°), the substance is obtained in 

 colorless scales or in flat needles, melting at 137°. 



0.1889 gram substance dried at 110° gave 0.4510 gram CO2 and 

 0.0997 gram HoO. 



