Bromoxynil

• 3,5-dibromo -4- hydroxybenzonitrile
• 3,5-dibromo -4- hydroxyphenylcyanid

Solid fuel

Fixed

1.632 g · cm -3

188.7 ° C

318.2 ° C

1.7 x 10-4 Pa ( 25 ° C)

• Poorly soluble in water (0.13 g · l-1 at 25 ° C ) and hexane
• Soluble in 1 -octanol (5.0 g · l-1 at 25 ° C ) and methanol (8.5 g · l-1 at 25 ° C)

Risk

Template: Infobox chemical / molecular formula search available

Bromoxynil is a chemical compound from the group of organic bromine compounds and benzonitriles.

History

Bromoxynil in 1965 registered in the United States for the first time as a herbicide. From 1972 limits for the presence in meat products and fruit and vegetables in 1980 there were enacted. It also comes in the form of a butyrate, octanoate or heptanoate derivative used, but with the approval of the butyrate derivative was withdrawn in 1989 due to concerns about its dangerousness.

Production and representation

Bromoxynil can be obtained by reaction of 4- hydroxybenzaldehyde with bromine followed by reaction with hydroxylamine.

Properties

Bromoxynil is a solid which is sparingly soluble in water. Bromoxynil octanoate and bromoxynil heptanoate are brown crystalline solids with a melting point of about 44 ° C.

The esters are practically insoluble in water. Bromoxynil octanoate is soluble in acetone and ethanol (10 g/100 ml), benzene, and xylene (70 g/100 ml), chloroform and dichloromethane (80 g/100 ml ) and cyclohexanone (55 g/100 ml). Bromoxynil heptanoate is soluble in 1- octanol ( 33.8 g/100 ml ), methanol ( 52.4 g/100 mL), hexane (77.5 g/100 ml), dichloromethane ( 111.1 g/100 ml ), acetone ( 106.4 g/100 ml) and ethyl acetate ( 102.7 g/100 ml). The octanoic and heptanoic readily hydrolyze to bromoxynil under alkaline conditions.

Use

Bromoxynil is used as an active ingredient in pesticides. It is a selective herbicide on the foliage Applied to contain various grasses and broadleaf broadleaf weeds (especially in grain and corn postemergence ). The substance inhibits the photosynthetic electron transport ( Hill - reaction), and also affects the oxidative phosphorylation in the mitochondria. Thus, the energy production and respiration of plants is affected. Some plants have bromoxynil nitrilase by the enzyme resistant to the herbicide.

In Germany, Switzerland and Austria bromoxynil is included (sometimes in combination with other agents such as terbuthylazine, Prosulfuron, isoproturon, Ioxynil and fluroxypyr ) in various herbicides.

Safety

Bromoxynil is similar to the related Ioxynil in mammals only moderately toxic, but highly toxic to fish.