urbaf2

NITRO DERIVATIVES OF TOLUENE^283

CHEMICAL PROPERTIES

The methyl group in dinitrotoluenes is particularly reactive due to the presence
of two nitro groups. Thus it readily undergoes such reactions as for example with
p- nitrosodimethylaniline to form an anil:

(6)

or with benzaldehyde, in the presence of piperidine, to form a stilbene derivative:

(7)

TABLE 51

HEAT OF NITRATION OF MONO- TO DINITROTOLUENE (CF. FIG. 50)

Starting product Nitration product

Reaction heat

kcal/mole

o- Nitrotoluene

o- Nitrotoluene

p- Nitrotoluene

m- Nitrotoluene

m- Nitrotoluene

m- Nitrotoluene

m- Nitrotoluene

2.4-Dinitrotoluene

2,6-Dinitrotoluene

2,4-Dinitrotoluene

2,3-Dinitrotoluene

3,4-Dinitrotoluene

3,6-Dinitrotoluene

3,5-Dinitrotoluene

+29.7

+28.2

+21.3

+18.8

+18.5

+23.2

+25.4

Under the influence of alkalis it forms a stilbene derivative, especially easily

in the presence of oxidizing agents (air oxygen, NaOCl):

(8)

The ease of these reactions can be explained in terms of the hyperconjugation

of toluene accentuated by the influence of the nitro groups.