N,N-Dimethyl-p-toluidine Property

Melting point:

-25°C

Boiling point:

211 °C(lit.)

Density 

0.937 g/mL at 25 °C(lit.)

vapor density 

>1 (vs air)

vapor pressure 

0.1 hPa (20 °C)

refractive index 

n20/D 1.546(lit.)

Flash point:

182 °F

storage temp. 

Store below +30°C.

solubility 

0.65g/l

form 

Liquid

pka

pK1:7.24(+1) (25°C)

color 

Clear yellow

explosive limit

7%

Water Solubility 

Miscible with alcohol, ether and chloroform. Immiscible with water.

BRN 

774409

Dielectric constant

3.3（20℃）

Stability:

Stable. Combustible. Incompatible with strong oxidizing agents.

InChIKey

GYVGXEWAOAAJEU-UHFFFAOYSA-N

LogP

1.729-2.81 at 35℃

CAS DataBase Reference

99-97-8(CAS DataBase Reference)

IARC

2B (Vol. 115) 2018

EPA Substance Registry System

N,N,4-Trimethylaniline (99-97-8)

Safety

Hazard Codes 

T

Risk Statements 

23/24/25-33-52/53

Safety Statements 

28-36/37-45-61-28A-51-44-36-22-20/21

RIDADR 

1708

WGK Germany 

3

RTECS 

XU5803000

F 

8-10-23

Autoignition Temperature

425 °C

TSCA 

Yes

HS Code 

2921 43 00

HazardClass 

6.1

PackingGroup 

II

Hazardous Substances Data

99-97-8(Hazardous Substances Data)

Toxicity

LD50 orally in Rabbit: 1650 mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H330Fatal if inhaled

H373May cause damage to organs through prolonged or repeated exposure

H412Harmful to aquatic life with long lasting effects

Precautionary statements

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P314Get medical advice/attention if you feel unwell.

N,N-Dimethyl-p-toluidine Chemical Properties,Usage,Production

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

Uses

N,N-Dimethyl-p-toluidine is used as a polymerization catalyst for polyesters, acrylate and epoxy resins. It is also used as a hardener for dental cements and in adhesives. It serves as an intermediate for photographic chemicals, in industrial glues, in artificial fingernail preparations, colorants, pharmaceuticals. It reacts with vinyl ether in the presence of copper(II) chloride gives tetrahydroquinolines. Further, it is used to accelerate polymerization of ethyl methacrylate.

Synthesis Reference(s)

Synthetic Communications, 19, p. 3051, 1989 DOI: 10.1080/00397918908052700
Tetrahedron Letters, 8, p. 1849, 1967

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.

Air & Water Reactions

Tends to darken upon exposure to air. Insoluble in water.

Reactivity Profile

N,N-Dimethyl-p-toluidine 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.

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.

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.]