Description
Bifenox is a herbicide for the control of broadleaved weeds and some grasses. It has a low aqueous solubility, is volatile and would not be expected to leach to groundwater. It would also not be expected to persistent in soil or water systems. It has a low mammalian toxicity and no serious health concerns have been identified. Bifenox is moderately toxic to fish, aquatic invertebrates and earthworms but is highly toxic to algae.
Uses
Selective preemergence or postemergence herbicide used to effectively control a wide variety of broad-leaved weeds (such as bindweed, jimsonweed, kochia, mustards, pigweeds, sesbania, smartweed and velvet-leaf) in tolerant crops (corn, grain sorghum, maize, rice and soybeans).
Definition
ChEBI: MC-4379 is a nitrobenzoic acid.
Production Methods
Bifenox is synthesised through a multi-step process culminating in an Ullmann condensation reaction. The final step involves reacting the potassium salt of 2,4-dichlorophenol with methyl 2-nitro-5-chlorobenzoic acid to form the herbicidal compound. The precursor, methyl 2-nitro-5-chlorobenzoic acid, is itself produced via a five-step synthesis starting from toluene, involving chlorination, oxidation to benzoic acid, methylation, and nitration.
Agricultural Uses
Herbicide: Used to control a variety of broadleaf weeds and
grasses in legumes such as soybeans and peanuts, and
post-emergent weed control in wheat, barley and sugar
beets. Not currently registered in the U.S. However, it is
used in 21 European countries and there are 27 global
suppliers.
Trade name
ALIBI®; FOX®; MODOWN®[C]; MC-
4379®; SABINE®
Mechanism of action
Selective, absorbed by foliage, new shoots and roots to inhibit protoporphyrinogen oxidase
Environmental Fate
Soil. Bifenox degrades in soil forming 5-(2,4-dichlorophenoxy)-2-nitrobenzoic acid
and methyl 5-(2,4-dichlorophenoxy)anthranilate (Hartley and Kidd, 1987; Smith 1988).
The average half-life in soils is 7–14 days (Hartley and Kidd, 1987; Humburg et al., 1989)
Plant. Rapidly undergoes ring hydroxylation and subsequent conjugation in rice plants
(Ashton and Monaco, 1991).
Photolytic. The UV photolysis (λ = 300 nm) of bifenox in various solvents was studied
by Ruzo et al. (1980). In water, 2,4-dichloro-3′-(carboxymethyl)-4′-hydroxydiphenyl ether
and 2,4-dichloro-3′-(carboxymethyl)-4′-aminodiphenyl ether were identi
