urbaf2

AROMATIC NITRO COMPOUNDS 225

OTHER REACTIONS OF NITRO COMPOUNDS

All aromatic. nitro compounds yield chloropicrin when treated with alkaline

solutions of hypochlorous acid salts. The reaction occurs at room temperature

or below (the lower the temperature the higher the yields).

The reaction was first observed by Stenhouse [146] in 1847, when treating picric

acid with a hypochlorite. According to A. W. Hofmann [147], a 114 wt. % yield could

be obtained in the reaction. As Gardner and Fox [148] reported, the yield could

be increased up to 180 - 190%. A yield of chloropicrin amounting to about 200%

can be obtained by introducing gaseous chlorine into a suspension of sodium

picrate in a solution of sodium carbonate at 0°C (Orton and McKie [149]).

It can be assumed that complete transformation of the nitro groups to chloro-

picrin takes place in the reaction:

C 6 H 2 (NO 2 ) 3 OH + 11Cl 2 + 5H 2 O -> 3CCl 3 NO 2 + 13HCl + 3CO 2 (37)

At higher temperatures side reactions occur, among others the formation of nitric

acid, while the yield of chloropicrin decreases.

Orton and McKie give the following maximum yields of chloropicrin, obtained

from various nitro compounds:

from picric acid 96-97% of the theoretical yield

from 2,4-dinitrophenol 50% ” ” ” ”

from p- nitrophenol 33-34% ” ” ” ”

from o- nitrophenol 10% ” ” ” ”

from 2,4,6-trinitrotoluene 82-84 wt. %

from 1,3,5-trinitrobenzene 53 ” %

For the last two compounds the yields are given in wt. %, since the stoichiometry

of the reactions is not known accurately.

LITERATURE

1. G. KÖRNER and A. CONTARDI, Atti. r. acad. Lincei. Roma [5], 23, I, 633; II, 464 (1914).


2. A. T. PETERS, F. M. ROWE and D. M. STEAD, J. Chem. Soc. 1943, 233, 576.


3. W. QVIST, Acta Acad. Aboensis, Math. Phys. 19, 1, 4, 5 (1953).


4. W. QVIST and G. LINDROOS, Acta Acad. Aboensis, Math. Phys. 20, 6 (1955).


5. W. QVIST and R. O. NORMES, Acta Acad. Aboensis, Math. Phys. 20, 13 (1956).


6. H. J. ACKERMANN, H. A. BALTRUSH, H. H. BERGES, D. 0. BROOKOVER and B. B. BROWN
   J. Agric. Food Chem. 6, 747 (1958).
   6a. K. L. GANGULY, Ber. 58, 708 (1925).


7. G. C. FINGER and C. W. KRUZE, J. Am. Gem. Soc. 78, 6034 (1956).


8. E. KOENIGS, H. CH. GERDE~ and A. SIROT, Ber. 61, 1028 (1928).
   8a. H. J. HERTOO and W. P. COMBÉ Rec. trav. chim. 70, 581 (1951).