134 • PROCEEDINGS OP THE AMERICAN ACADEMY. 



rather than strict determiuations, as must necessarily be the case where 

 the products are purified by crystallization. The numbers are percent- 

 ages of the theoretical yield in each case : — 



C6HBr(OC2H6)2(N02)2, melting point 184° . . 22 per cent. 



C6HBr(OC2H5)2(N02)2, melting point 92° . . 19 per cent. 



C6H(OC2H5)3(N02)2, melting point 105° . . 19 per cent. 



C6H2(OC2H,)OH(N02)2, melting point 77° . . 6 per cent. 



C6HBr3(N02)OH, melting point 90° ... . 1 per cent. 



Total 67 per cent. 



It appears from this that the principal reaction is that which forms the 

 bromdinitroresorcine diethylether melting at 92°, since the dinitrophloro- 

 glucine triethylether must be formed from this by a secondary reaction, 

 and the yield of the two together is 38 per cent. Next after this comes 

 the reaction forming the bromdinitroresorcine diethylether melting at 

 184°, and its decomposition product, the dinitroresorcine raonoethylether, 

 as these together make up 28 per cent of the theoretical yield ; while 

 the third primary reaction, that which forms the tribromnitrophenol, is of 

 very inferior importance, yielding only one per cent. These results also 

 make it probable that no other product was formed in any considerable 

 amount, as the percentage unaccounted for (33) is no greater than the 

 loss which would be expected from such numbers of crystallizations, and 

 other wasteful methods of purification, as were necessary in isolating the 

 substances enumerated. Small quantities of oily products were observed 

 at various points in the work, as stated in the description of the purifica- 

 tion, but except for these all the products were recognized. 



Constitution of the Dinitroresorcine Diethylether melting at 133°. 

 The dinitroresorcine diethylether was boiled for some time with sul- 

 phuric acid of specific gravity 1.44 in a flask with a return cooler. The 

 reaction runs smoothly, and gives an almost quantitative yield of the 

 symmetrical dinitroresorcine (0C^ll,\\,b,(1^0^).^A. This was recog- 

 nized by its melting point 210° -211° ; Typke * gives 212°.5, Schiapa- 

 relli and Abellif 214°.5, both of which are higher than that observed by 

 us ; but, as only two dinitroresorcines could be formed from tribromdini- 

 trobenzol, the symmetrical one, whose melting point is given above, and 

 the adjacent, which melts at 142°, there can be no doubt about the iden- 



* Ber. d. chem. Ges., XVI. 552. 

 t Ibid., XVI. 872. 



