General Description
A clear colorless liquid with an aromatic odor. Density 0.937 g/cm3 (Lancaster) and insoluble in water. Hence floats on water. Toxic by skin absorption and inhalation. Flash point 181°F. May release toxic vapors when burned.
Reactivity Profile
N,N-DIMETHYL-P-TOLUIDINE(99-97-8) neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. May generate hydrogen, a flammable gas, in combination with strong reducing agents such as hydrides.
Air & Water Reactions
Tends to darken upon exposure to air. Insoluble in water.
Health Hazard
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Fire Hazard
Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.
Chemical Properties
light yellow liquid
Uses
N,N-Dimethyl-4-toluidine is an amine accelerator for the polymerization of e.g. dental methacrylic restorative materials
Synthesis
N,N-Dimethyl-p-toluidine was prepared by reacting p-toluidine with methanol and POCl3 in autoclave heated up to 280° C for 3h.
Purification Methods
Reflux for 3hours with 2 molar equivalents of Ac2O, then fractionally distil it under reduced pressure. Alternatively, dry it over BaO, distil and store it over KOH. The picrate has m 128o (from EtOH). Methods described for N,N-dimethylaniline are applicable here. [Beilstein 12 H 902, 12 III 2026, 12 IV 1874.]
