JACKSON AND GRINDLEY. — ACETALS FROM QUINONES. 427 



159°-160°, the melting point* of the dichlorhydroquinonedimalonic 

 ester discovered by J. Stieglitz ; * our dichlorquinonedimalouic ester 

 is therefore identical with that obtained by him from the direct action 

 of sodium malouic ester on chlorauil. Our indirect method of pre- 

 paring it, however, gives a better yield than the direct method, 27 per 

 cent instead of 10 per cent. That we might not intrude on this field 

 of research already occupied by Stieglitz, we have confined our work 

 on this substance to that necessary for establishing its identity. 



Sodium Salt of Dichlorqamonedimalonic Ester, 

 C6Clo(CNa(COOC2H5)2)202. 



In order to prepare this salt the dichlorquinonedimalonic ester was 

 dissolved in ether, and treated with rather less than the required 

 amount of sodic ethylate in a strong alcoholic solution. The sodium 

 salt separated at once as a blue precipitate, which was repeatedly 

 washed with ether by decantation, and dried over sulphuric acid and 

 paraffine until the weight remained constant,* after which the sodium 

 was determined with the following result : — 



0.2788 gram of the salt gave 0.0731 gram of sodic sulphate. 



Calculated for 

 CgCljCCNaCCOOCaHjjo)^- Found. 



Sodium 8.57" " 8.49 



The sodium salt has a beautiful blue color, and is very easily soluble 

 in water, givino- a solution of a blue color as intense and strikinEf as 

 that of aniline blue. It is somewhat soluble in alcohol, but insoluble 

 in ether. 



Diethoxyqidnonedimalonic Ester, C6(OC2H5)2(CH(COOC2H5)2)202. 



In the first attempt to form the sodium salt of the dichlorquinone- 

 dimalonic ester, the substance was dissolved in absolute alcohol and 

 boiled with an excess of dry sodic carbonate. When the sodic car- 

 bonate was first added, the alcoholic solution was colored dark blue ; 

 but after filtering out the excess of sodic carbonate and evaporating 

 rapidly, the solution became nearly colorless, and left after the alcohol 

 had been driven off a residue of almost white crystals, which were 

 purified by crystallization from alcohol until the melting point re- 

 mained constant at 115°. The analysis of the substance dried over 

 sulphuric acid and paraffine gave the following results : — 



* Am. Chem. Journ., XIII. 38. 



