172 PROCEEDINGS OF THE AMERICAN ACADEMY 



Properties of Dinitroresorcine Diethylether, C^Y{.-^{C.^Y{f))./J^O.^^. 

 — Tliis substance crystallizes by cooling from an alcoholic solution in 

 long slender needles or flattened prisms with a sharp point. If the 

 alcoholic solution is allowed to evaporate spontaneously, it forms some 

 curling hair-like crystals which are very characteristic. The crystals 

 from alcohol are also apt to form clumps of radiating hairs shaped 

 somewhat like a toadstool, especially if the substance is not absolutely 

 pure. From ether it crystallizes in needles combined longitudinally 

 into prisms with prickly ends ; from chloroform, in radiating needles. 

 It melts at 133°, and is nearly insoluble in water, although apparently 

 a little more soluble in it hot than cold ; not very soluble in cold 

 alcohol, freely in hot; more soluble in methyl than in ethyl alcohol, 

 whether cold or hot ; freely soluble in chloroform, glacial acetic acid, 

 or acetone ; soluble in benzol ; slightly soluble in ether ; very slightly 

 in carbonic disulphide ; essentially insoluble in ligroine. Alcohol is 

 the best solvent for it. Strong sulphuric acid dissolves it in the cold, 

 forming a yellow solution ; strong nitric acid has no action on it when 

 cold, but gives a colorless solution if heated with it ; strong hydro- 

 chloric acid has no action on it, whether hot or cold. 



Conversion of Bromdinitroresorcine Diethylether into Dinitro- 

 resorcine Diethylether . 



It has been shown in the two preceding sections that the action of 

 sodic ethylate on tribromdinitrobenzol differs according to the condi- 

 tions under which it takes place, since in the cold bromdinitroresor- 

 cine diethylether is formed, but when the mixture is heated the third 

 atom of bromine is also removed and replaced by hydrogen, so that 

 the product is the dinitroresorcine diethylether. In order to throw 

 more light on this substitution of hydrogen for the third atom of bro- 

 mine we next tried the action of sodic ethylate when heated on the 

 bromdinitroresorcine diethylether, as it was possible that this substitu- 

 tion could take place only at the moment of the replacement of the 

 other two atoms of bromine by the ethoxy radicals, and in that case 

 boiling sodic ethylate would not convert the ready formed bromdini- 

 troresorcine diethylether into'the dinitroresorcine diethylether. Ac- 

 cording]}' 3 gr. of bromdinitroresorcine diethylether were mixed with 

 the sodic ethylate from O.G gr. of sodium dissolved in alcohol,* and the 



* We found that benzol must not be added in this case, as it seemed to inter- 

 fere with the progress of the reaction. 



