JACKSON AND GRINDLEY. — ACETALS FROM QDINONES. 431 



That this product was the same as that prepared from the dichlor- 

 dipheuoxyquiuoiie was showu also by its properties, which agreed 

 with those observed for that substauce, especially by its very charac- 

 teristic reaction with dilute acids. 



The other product obtained from the green salt formed by the 

 action of sodic methylate on chloranil was dissolved in the alcohol 

 used in washing the dirty white precipitate from dilute sulphuric acid ; 

 after evaporating off the alcohol, it was purified by recrystallizatiou 

 from dilute alcohol, and analyzed with the following result : — 



0.2094 gram of the substance gave by the method of Carius 0.4841 

 gram of argentic chloride. 



Calculated for CuCl4(OH)2. Found. 



Chlorine 57.25 57.16 



As it melts at 235°, there can be no doubt that it is the tetrachlor- 

 hydroquinone, the melting point of which is given by Sutkowski * as 

 232°. We are unable to determine at present whether this tetrachlor- 

 hydroquinone is due to a secondary reaction, or whether it proceeds 

 from that by which the hemiacetal is made. Sodic ethylate does not 

 act in this way with chloranil. 



The dichlordimethosyquinone dimethylhemiacetal is also formed 

 when dichlordimethoxyquinone melting at 141°'-142° is treated with 

 two equivalents of sodic methylate dissolved in methyl alcohol. 



Properties of the Dichlordimethoxyquinone Dimethylhemiacetal. — It 

 is a white amorphous solid, insoluble in all the common solvents. 

 It is very easily converted into the red dichlordimethoxyquinone, 

 melting at 141°-142°, discovered by Kehrmann.f This change can 

 be effected by heat alone, since in the neighborhood of 160° it begins 

 to take on a slight reddish color, which becomes darker very slowly at 

 this temperature, but when heated to 195° or higher the substance 

 melts to a red liquid, at the same time increasing very much in volume 

 and giving otF many bubbles of gas consisting probably of the vapor 

 of methyl alcohol. Tlie decompostion point is not a definite one, as 

 in different trials this action took place at temperatures sometimes as 

 much as twenty or twenty-five degrees apart. An easier way to 

 bring about this change is by treating the hemiacetal with dilute 

 sulphuric acid or dilute hydrochloric acid, to either of which it shows 

 itself remarkably susceptible, the decomposition taking place quanti- 



* Ber. d. ch. G., XIX. 2316. t Journ. Prakt. Chem., [2.], XL. 370. 



