Description
2,3,6-TBA is a post-emergence herbicide. It is highly soluble in water and most organic solvents. It is considered volatile. Little has been reported on its environmental persistence or mobility. It is moderately toxic to mammals and a recognised irritant. Based on its chemical properties it would not expected to bioaccumulate. There are gaps in knowledge regarding its toxicity to biodiversity however data has shown that it is moderately toxic to bids, fish and honeybees.
Chemical Properties
A solid.
Hazard
Poison; moderately toxic.
Mechanism of action
Systemic, absorbed by leaves and roots with auxin type action
Safety Profile
Poison by intraperitoneal route.Moderately toxic by ingestion and subcutaneous routes.When heated to decomposition it emits toxic fumes ofClí. Used as an herbicide.
Synthesis
The general procedure for the synthesis of 2,3,6-trichlorobenzoic acid from 2,3,6-trichlorobenzene was as follows: 2,3,6-trichlorobenzene was added to 100 mL of water, followed by the addition of 0.4 g of tetrabutylammonium chloride as a phase-transfer catalyst, and 63 g of potassium permanganate. The reaction mixture was heated to 50 °C for 6 hours. Upon completion of the reaction, the pH of the filtrate was adjusted to 3 with 5% hydrochloric acid solution (mass percent, as HCl), at which time a large amount of white solid precipitated. The precipitate was collected by filtration, washed with a small amount of water and dried to give 43.3 g of 2,3,6-trichlorobenzoic acid with 95% purity and 96% yield by HPLC.
Environmental Fate
Photolytic. Plimmer (1970) postulated that the irradiation of 2,3,6-trichlorobenzoic
acid in methanol will undergo dechlorination forming 2,3-, 2,6- and 3,6-dichlorobenzoic
acids. Further irradiation may yield 2- and 3-chlorobenzoic acids which may ultimately
form benzoic acid (Plimmer, 1970).
Chemical/Physical. Reacts with alkalies and amines forming water-soluble salts.
References
[1] J. Appl. Chem. USSR (Engl. Transl.), 1980, vol. 53, # 12, p. 2076 - 2078
[2] Zhurnal Prikladnoi Khimii (Sankt-Peterburg, Russian Federation), 1980, vol. 53, # 12, p. 2737 - 2740
[3] Patent: CN105294419, 2016, A. Location in patent: Paragraph 0105; 0106
[4] Journal of the Chemical Society, 1951, p. 1208,1212
[5] Journal of the Chemical Society, 1902, vol. 81, p. 1335
