Xylidines


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Xylidines

 

aminoxylenes, (CH3)2C6H3NH2. All six isomers are known (see Table 1).

Table 1. Some properties of xylidines
XylidinePosition of groups in benzene ringBoiling point (°C)Density, g/cm3(att)
CH3NH2  
*Melting point, 51 C † At 739 mm Hg (1 mm Hg − 133.322 newtons per m2
‡At 728 mm Hg §Melting point, 15.5°C
Ordinary o-x........1.232210.9910 (15°C)
Asymmetrical o-x*....1.242261.0755 (17.5°C)
Ordinary m-x......1.32214†0.9796 (20°C)
Asymmetrical m-x.....1.34216‡0.9783 (19.6°C)
Symmetrical m-x.....1.352200.9935 (0°C)
ρ-x§ ...........1.42213.40.9790 (21.3°C)

All xylidines are colorless substances with an odor of aniline; they darken rapidly on exposure to air. They are readily soluble in organic solvents, and poorly soluble in water. Xylidines form highly explosive vapor-air mixtures. They exhibit a toxic effect on blood and damage the liver. They are bases and readily form salts and undergo diazotization. Xylidines are obtained by nitration of xylenes and subsequent reduction of nitro compounds. The isomers are separated by the fractional crystallization of their salts. Xylidines serve as antioxidants and frothing agents in flotation processes. They are also used in the preparation of azo dyes.

References in periodicals archive ?
Xylidines are carcinogenic compounds originating from missile fuel and are dominating in polluted groundwater in the areas of abandoned Soviet missile bases in Eastern Europe.
A steady-state mathematical model that takes into account the mass transfer between phases, the reaction between ozone and xylidine, xylidine vaporization, the enhancement of the mass transfer due to the reaction between ozone and xylidine, and the stoichiometric ratio of the consumed ozone to the reacted xylidine was developed for the wetted-wall reactor.
2) is supposed to take place in the 2,4-xylidine degradation process; the first step for xylidine oxidation is probably just the formation of nitroaromatics.
The adsorption isoterms, xylidine diffusion coefficient in GAC pores, and breakthrough curves are presented in [7].