Ryan and O'Kiokijan — On a-, /3-, and y- Trinitrotoluenes. 177 



obtained, the compounds yielding trinitrobenzene and trinitroxylenc 

 respectively. 



According to Meisenheimer (Liebig's Annalen der Chemie cccxxiii (1IJ02), 

 pp. 205-246) the formula of Hantzsch and Kissel is not correct. He found 

 that the compound of potassium methylate with the ethyl ether of picric 

 acid is identical with that formed from potassium ethylate and the methyl 

 ether of picric acid, whereas according to the formula of Hantzsch and Kissel 

 two different substances should be obtained. Meisenheimer proposed the 

 formula II for this compound, 



C.H 5 0\/OCH 3 



/\ 

 NU>\/ \/N0 2 



II II II 

 \ / 

 \/ . 



II 



O^N-OK 



this formula being surjported by work on the nitro-derivatives of anthracene, 

 and also by the fact that on decomposition by acids it yields a mixture 

 of the methyl and ethyl ethers of picric acid. The deep colours of this and 

 similar compounds are due, according to Meisenheimer, to their quinonoid 

 structure. 



Hantzsch and Picton (Ber. d. Dtsch. Chem. Ges. xlii (1909), pp. 2119-2128) 

 were not in agreement with either the formula of Meisenheimer or that of 

 Hantzsch and Kissel ; they argued that the deep colours of these compounds 

 show that more than one nitro group must be affected by the added alcoho- 

 lates, since the salts of mononitro compounds are colourless. According to 

 Hantzsch and Picton trinitrobenzene-potassium methylate is represented by 

 formula III (a, b, c, or d) : — 



H\/OCH 3 H\/OCH 3 



/\ /\ 



O.N— / III N— NO: (),N— /ill V-N0 2 



a b 



\ / \ / 



\/ \/ 



N0 2 N0 2 



H\/OCH 3 H\/OCH 3 



/\ A 



0,i\ _/ III ^N : OjN —( II I V-NO . OK 



I 



</ 



\ / \ / 



\/ ! \/ 



i i ii 



Kd . uN NO — 



Busch and Koegel (Ber. d. Dtsch. L'hem. Ges. xliii (1910), pp. 1549-64) state 

 that picryl aniline unites with one, two, or throe uioh-culcs uf an ak-oholate, 

 and that all polynitro-benzene derivatives behave similarly ; the higher 

 alcohols, especially, have a marked tendency to form * i i - and tri-alcoholates. 



According to Green and his en-workers (Jour. (hem. Soc., 1904, 

 pp. 1424-31, 14:i2-o.S; 19U7, pp. 2076-83 ; 1908, pp. 172 1 -26), ^-uitrotoluene 



