1,2,4-Триметилбензол

Описание

1,2,4-Trimethylbenzene (mesitylene) is an aromatic hydrocarbon compound commonly present in commercial solvents encompassing their boiling range. Mesitylene are the most common isomer used in commercial applications. Aromatic hydrocarbons in hydrocarbon solvents are predominantly alkylated one ring structures as well as two aromatic ring structures which may also be alkylated.

Химические свойства

colourless liquid. Insoluble in water, soluble in ethanol, ether and benzene.

Физические свойства

Colorless liquid with a slight aromatic odor. A detection odor threshold concentration of 12 mg/m³ (2.4 ppm_v) was experimentally determined by Dravnieks (1974).

Использование

1,2,4-Trimethylbenzene is the unlabelled version of 1,2,4-Trimethyl 13C6-benzene (T796173), a labelled aromatic standard.

Определение

ChEBI: 1,2,4-trimethylbenzene is a trimethylbenzene carrying methyl groups at positions 1, 2 and 4. It has a role as a neurotoxin.

Общее описание

A liquid. Flash point near 130°F. Less dense than water and insoluble in water. Vapors irritate eyes, throat, and nose. Used in dyes and pharmaceuticals.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

1,2,4-Trimethylbenzene is incompatible with the following: Oxidizers, nitric acid .

Опасность

Moderate fire risk. Central nervous system depressant, irritant to mucous membranes. Asthma and hematologic effects.

Угроза здоровью

Harmful if inhaled or swallowed. Vapor or mist is irritating to the eyes, mucous membrane and upper respiratory tract. Prolonged contact can cause dermatitis, nausea, headache, dizziness, and narcotic effect.

Профиль безопасности

Moderately toxic by intraperitoneal route. Mildly toxic by inhalation. Can cause central nervous system depression, anemia, bronchitis. Flammable liquid when exposed to heat, sparks, or flame. To fight fire, use foam, alcohol foam, mist. Emitted from modern building materials (CENEAR 69,22,91). When heated to decomposition it emits acrid smoke and irritating fumes.

Экологическая судьба

Biological. In anoxic groundwater near Bemidji, MI, 1,2,4-trimethylbenzene anaerobically biodegraded to the intermediate 3,4-dimethylbenzoic acid and the tentatively identified compounds 2,4- and/or 2,5-dimethylbenzoic acid (Cozzarelli et al., 1990).
Photolytic. Glyoxal, methylglyoxal, and biacetyl were produced from the photooxidation of 1,2,4-trimethylbenzene by OH radicals in air at 25 °C (Tuazon et al., 1986a). A rate constant of 2.0 x 10^-8 L/molecule?sec was reported for the reaction of 1,2,4-trimethylbenzene with OH radicals in the gas phase (Darnall et al., 1976). Similarly, the rate constants for the reaction of 1,2,4- trimethylbenzene and OH radicals at room temperature were 3.35 x 10^-11 (Hansen et al., 1975) and 3.84 x 10^-11 cm³/molecule?sec (Atkinson, 1985). At 25 °C, a rate constant of 3.15 x 10^-11 cm³/molecule?sec was reported for the same reaction (Ohta and Ohyama, 1985). Products identified from the OH radical-initiated reaction of 1,2,4-trimethylbenzene in the presence of nitrogen dioxide were 3-hexene-2,5-dione and 2,3-butanedione (Bethel et al., 2000).
Chemical/Physical. 1,2,4-Trimethylbenzene will not hydrolyze in water (Kollig, 1993).

Методы очистки

Reflux pseudocumene over sodium and distil it under reduced pressure. [Beilstein 6 H 1088, 6 I 542, 6 II 1072, 6 III 6278, 6 IV 7339.]