68 PROCEEDINGS OP THE AMERICAN ACADEMY 



would be to increase the acidity of the compound ; whereas if the 

 atom of hydrogen on tlie side-chain were replaced, the substance 

 would cease to show acid properties, as the NO2 would have taken 

 the place of the only atom of hydrogen which can be replaced by a 

 metal. Upon studying the behavior of the new compound with alka- 

 line reagents, we found that none of them affected it in aqueous solu- 

 tion, and that it was acted on only by sodic hydrate or ethylate in 

 alcoholic solution, thus showing a marked contrast to the behavior of 

 bromtrinitrophenylmalonic ester, which is acid enough to decompose 

 sodic carbonate in aqueous solution. As just stated, sodic hydrate or 

 ethylate does act upon our substance, but the red solution formed by 

 the sodic ethylate was proved to contain sodic nitrite, and there- 

 fore the formation of the red salt was preceded by the removal 

 of the group NO2, which proves that this radical has replaced the 

 hydrogen of the side-chain, as represented in the formula given 

 above. This result was confirmed by the study of the compound 

 CcH2Br(N02)2CN02(COOC2Hg)2, which proved even less suscepti- 

 ble to the action of alkalies than the corresponding trinitro com- 

 pound. The replacement of the hydrogen in the malonic ester 

 radical is not at all strange, since Franchimont and Klobbie * have 

 found that nitric acid converts malonic ester into nitromalonic ester. 



To determine whether our substances were nitro compounds, that 

 is, with the radical NO2 attached to the side-chain by its nitrogen, or 

 nitrites, that is, with the radical attached by one of its atoms of oxy- 

 gen, we considered in the first place the further action of nitric acid upon 

 the compound C,;HBr(N02)3CN02(COOC2H5)2, which converted it 

 after warming for three hours into C6llBr(N02)3C01I( 0000,115)2, 

 that is, the bromtrinitrotartronic ester; the reaction seemed to run 

 smoothly, and the yield was 40 per cent of the theory. A similar 

 change was produced by heat; when exposed to a temperature of 

 124°-126°, the substance melted, turned blood- red, and gave off a 

 great deal of gas, with a striking increase in volume at the same 

 time.t A study of the gases showed that a part of the substance 



« Ber. d. eh. G., XXIII., R. 62 from Rec. Trav. Chitn., VIII. 283. For a dis- 

 cussion of tiie efTict of different radicals upon tlie action of nitric acid on fat 

 substances, see Franchimont, Per. d. ch. G., XX., R. G89 from Rec. Trav. Cliim., 

 VI. 224, and Ber. d ch. G., XXIII., R. 64 from Rec. Trav. Cliim., Vlll. 307. 



t Tliese phenomena shown by our substance in melting, as well as many of 

 its other properties, are very similar to those observed by Gabriel in the cases 

 of the benzylidenplithaliddinitrite, Ber. d. ch. G., XVIII. 1255, and tlie etliin- 

 diphtlialiiidinitrite, Her. d. ch. G., XIX. 837, which confirms the view that our 

 substance is a nitrite. 



