124 PROCEEDINGS OF THE AMERICAN ACADEMY. 



or, putting it into words, the attack upon tlie nitro groups will be insignifi- 

 cant compared to tiiat on the atoms of bromine. This is in accord with 

 our experimental results already given, since the attack on the nitro 

 groups (Reaction III.) was to the attack on the atoms of bromine (Re- 

 actions I. and II.) as 1 to 6G. 



From the yields of the two bromdinitroresorcine diethylethers, given 

 earlier in this paper, it is possible to draw conclusions in regard to the 

 effect of the position of the nitro groups in loosening the atoms of bro- 

 mine, but there is some question whether such conclusions are valid, 

 since the difference between the yields of the two bromdinitroresorcine 

 diethylethers is only ten per ceut, and this amount is within the probable 

 limit of error in this case, where the purifications were made by crystal- 

 lization. On the other hand, the product melting at 92° (2) was obtained 

 in the larger quantity, and this is the one where we shovdd expect the 

 greatest loss, since in its purification the crystallizations were the most 

 numerous. We feel, therefore, justified in giving the following discussion 

 with all necessary reserve. In the two reactions (I. and II.) one of the 

 atoms of bromine replaced occupied in each case the same position (ortho- 

 para) toward the nitro groups, and therefore the difference between the 

 reactions depends on tiie position of the second atom of bromine replaced. 

 In Reaction I. this atom of bromine was ortho to one nitro group and 

 para to the other, and this reaction gave 28 per cent of the product com- 

 pared to 38 per cent from Reaction II., in which the atom of bromine 

 was in the ortho position to both nitro groups. It would seem, therefore, 

 that the diortho position of the nitro groups exerted a stronger loosening 

 effect upon the bromine than the orthopara position. 



When the reaction between tribromdinitrobenzol and sodic ethylate is 

 carried on at 70°, the products isolated by us were the dinitroresorcine 

 diethylether melting at 133°, a little of the bromdinitroresorcine diethyl- 

 ether melting at 184°, and much of the isomeric substance melting at 

 92°. These were the only products we have succeeded in identifying, 

 although we obtained indications of the presence of the tribromnitro- 

 phenol. There was also a crystalline substance melting at 112°, but 

 in too small quantity for identification, and a great deal of tarry matter. 

 The absence of the dinitrophloroglucine triethylether is surprising ; 

 we should account for it by supposing that the reaction ran for so 

 short a time (ten minutes) that the bromdinitroresorcine melting at 92° 

 did not undergo decomposition. The hypothesis that the phloroglu- 

 cine ether formed was converted into tarry substances by the hot sodic 

 ethylate seems to us less probable. The approximate yields of the two 

 products of the reaction at 70° were : — 



