JACKSON AND GRINDLEY. — ACETALS FROM QUINONES, 441 



this dibenzoate from dichlordiethoxyhjdroquinone, and found that it 

 was entirely different from the saponification product, as it melts at 

 215° instead of 14:2°. The description of this substance is given 

 later in the paper. The supposition that the substance might contain 

 an obstinately adhering impurity was disposed of by frequent recrys- 

 tallizations. The sample for Analysis I. was crystallized only three 

 or four times, that for II. and III. ten times, that for IV. eight times. 

 There was no difference in the melting points of these three samples, 

 and, as the results given above show, no essential difference in their 

 percentage composition. We must therefore accept tlie formula 

 derived from these analyses, and the most probable Jiypothesis is that 

 the atom of oxygen spans the benzol ring between two atoms of 

 carbon in the para position, but we are unable to determine at present 

 whether this atom of oxygen proceeded from the saponification of the 

 ethoxy radicals of the acetal, and therefore lies between the two atoms 

 of carbon to which the benzoate groups are attached, or from the 

 two ethoxy groups of the chloranilic ester, and therefore spans the 

 ring between two other atoms of carbon. This latter supposition 

 seems to us the more probable, as it would give some explanation of 

 the ease with which the ethyls are removed. We wished to confirm 

 such an unusual hypothesis by studying the derivatives of this sub- 

 stance, but our work in this direction has not yet brought any con- 

 clusive evidence in regard to its constitution, and we therefore propose 

 this theory only as the most probable one, leaving to future work the 

 testing of its accuracy. It may be observed here that such a sub- 

 stance would be a natural product of the saponification of dichlor- 

 diethoxy(iuinone dibeuzoyldiethylacetal as shown by the following 

 reactions : — 



C6Cl2(OC2H5)o(OaH5)o(OCOCcH5)2 + 2 HoS04 = 



CeC]2(OC2H5)2(OH)o(OCOC6H5)2 + 2 C,H5HS04 = 



C6C]2(OC.,H5)20(OCOC6H5)2 + H2O + 2 C2H5HSO4. 



We would call the substance, in accordance with its provisional 

 formula, oxide of dichlordiethoxyhydroquinone dibenzoate, although it 

 may be instead the oxide of dichlorquinone ethylbenzoylacetal. 



Properties of the Oxide of Dichlordiethoxyhydroquinone Dihenzoate. 

 — It crystallizes in white well developed six-sided prisms, often of 

 considerable size, belonjiing either to the hexafjonal or orthorhom- 

 bic system. When crystallized more quickly, it. forms rather loose 

 rosettes of prisms terminated by several planes forming a very blunt 

 end. It shows a strong tendency to separate from its solutions in the 



