2835. 2,4-DB

Nomenclature

CAS number: 94-82-6
4-(2,4-Dichlorophenoxy)butanoic acid; 4-(2,4-dichlorophenoxy)butyric acid; Butyrac (Union Carbide); Legumex D.
C10H10Cl2O3; mol wt 249.09.
C 48.22%, H 4.05%, Cl 28.47%, O 19.27%.

Description and references

Selective post-emergence, translocated herbicide. First described as a plant growth regulator: M. E. Synerholm and P. W. Zimmerman, Contrib. Boyce Thompson Inst. 14, 369 (1947). Prepn: G. W. Kitchingman, A. C. Tucker, GB 804565 and GB 883255 (1958, 1961, both to ICI). Similar in activity to 2,4-D, q.v., but more selective. Mechanism of selectivity studies: D. L. King, D. E. Bayer, Proc. West. Soc. Weed Sci. 25, 37 (1972).

Chemical structure

Properties

White crystals, mp 117-119°. Soly in water at 25°: 46 ppm. Sol in acetone, ethanol, diethyl ether. Slightly sol in benzene, toluene, kerosene.

Derivative

Sodium salt.

Nomenclature

Embutox.
C10H9Cl2NaO3; mol wt 271.07.
C 44.31%, H 3.35%, Cl 26.16%, Na 8.48%, O 17.71%.

Properties

Water soluble; hard water will show precipitate as the calcium and magnesium salts.

Derivative

Dimethylamine salt.

Nomenclature

Butoxone.
C12H17Cl2NO3; mol wt 294.17.
C 48.99%, H 5.82%, Cl 24.10%, N 4.76%, O 16.32%.

Properties

Water sol; calcium and magnesium salts precipitate in hard water.

Use

Herbicide.