1,2,3,5-Tetrachlorobenzene

White crystals, melting point 51-52°C.

1,2,3,5-Tetrachlorobenzene is used in the synthesis of several organic compounds including that of polyarylated benzenes by multiple Suzuki-Miyaura reactions. It was used as part of study which investigated the antimicrobial activity of tetra substituted benzene derivatives which suggested antimicrobial activity tended to decrease with increasing size of halogen substituents.

ChEBI: A tetrachlorobenzene carrying chloro groups at positions 1, 2, 3 and 5.

White crystals or off-white solid.

Insoluble in water.

Simple aromatic halogenated organic compounds, such as 1,2,3,5-Tetrachlorobenzene , are very unreactive. Reactivity generally decreases with increased degree of substitution of halogen for hydrogen atoms. Materials in this group may be incompatible with strong oxidizing and reducing agents. Also, they may be incompatible with many amines, nitrides, azo/diazo compounds, alkali metals, and epoxides. 1,2,3,5-Tetrachlorobenzene may react with oxidizers. .

ACUTE/CHRONIC HAZARDS: 1,2,3,5-Tetrachlorobenzene may cause irritation on contact.

1,2,3,5-Tetrachlorobenzene is probably combustible.

Biological. A mixed culture of soil bacteria or a Pseudomonas sp. transformed 1,2,3,5-tetrachlorobenzene to 2,3,4,6-tetrachlorophenol (Ballschiter and Scholz, 1980). The half-life of 1,2,3,5- tetrachlorobenzene in an anaerobic enrichment culture was 1.8 d (Beurskens et al., 1993).
In an enrichment culture derived from a contaminated site in Bayou d’Inde, LA, 1,2,3,5- tetrachlorobenzene underwent reductive dechlorination to 1,2,4- and 1,3,5-trichlorobenzene at relative molar yields of 7 and 93%, respectively. The maximum dechlorination rate, based on the recommended Michaelis-Menten model, was 94 nM/d (Pavlostathis and Prytula, 2000).
Photolytic. Irradiation (λ ≥285 nm) of 1,2,3,5-tetrachlorobenzene (1.1–1.2 mM/L) in an acetonitrile-water mixture containing acetone (0.553 mM/L) as a sensitizer gave the following products (% yield): 1,2,3-trichlorobenzene (5.3), 1,2,4-trichlorobenzene (4.9), 1,3,5-trichlorobenzene (49.3), 1,3-dichlorobenzene (1.8), 2,3,4,4′,5,5′,6-heptachlorobiphenyl (1.41), 2,2′,3,4,4′,6,6′- heptachlorobiphenyl (1.10), 2,2′,3,3′,4,5′,6-heptachlorobiphenyl (4.50), four hexachlorobiphenyls (4.69), one pentachlorobiphenyl (0.64), trichloroacetophenone, 1-(trichlorophenyl)-2-propanone, and (trichlorophenyl)acetonitrile (Choudhry and Hutzinger, 1984). Without acetone, the identified photolysis products (% yield) included 1,2,3-trichlorobenzene (trace), 1,2,4-trichlorobenzene (24.3), 1,3,5-trichlorobenzene (11.7), 1,3-dichlorobenzene (0.5), 1,4-dichlorobenzene (3.3), pentachlorobenzene (1.43), 1,2,3,4-tetrachlorobenzene (5.99), two heptachlorobiphenyls (1.40), two hexachlorobiphenyls (<0.01), and one pentachlorobiphenyl (0.75) (Choudhry and Hutzinger, 1984).

Crystallise it from EtOH. [Beilstein 5 II 157, 5 III 551, 5 IV 668.]

The final ITSL for 1,2,3,5-TeCB is 12 μg/m3 (24-hour average). The Initial Threshold Screening Level for 1,2,3,5-tetrachlorobenzene is 12 μg/m3 with annual averaging time.