Flamprop
Weed control herbicide
From Wikipedia, the free encyclopedia
Flamprop is a selective post-emergent herbicide, used in Australia on wheat and triticale.[2] It is an arylalanine.[1] Flamprop comes in several chemical variants, including flamprop, flamprop-methyl, flamprop-isopropyl, flamprop-M, flamprop-M-methyl, and flamprop-M-isopropyl.[3] The information in the right hand side box is accurate for basic flamprop.
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| Names | |
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| Preferred IUPAC name
2-(N-Benzoyl-3-chloro-4-fluoroanilino)propanoic acid | |
Other names
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| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| EC Number |
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| KEGG | |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C16H13ClFNO3 | |
| Molar mass | 321.73 g·mol−1 |
| Appearance | White crystals[1] |
| Hazards | |
| GHS labelling: | |
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| Warning | |
| H302, H315, H319, H335 | |
| P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Initial research focussed on wild oats in cereal crops in the 60s and 70s, with several chemical variants studied.[4] Flamprop was introduced to the UK circa 1974, with variants coming a few years later.[1][5]
In the 90s, Flamprop's recommended application rate was 600 grams active ingredient per hectare.[6] In Australia, flamprop is sold as a 90 g/L concentrate, and applied at 112-225 g/Ha.[2]
Under moderately basic conditions, the varieties of flamprop are hydrolysed to their base acids and alcohols. Under more basic conditions, there can be cleavage of the amide bond, resulting in benzoic acid and the corresponding amino acid.[4]
By 2000, resistant wild oats (Avena fatua) were found in Canada, as well as oat species resistant to ACCase inhibitors and triallate, and difenzoquat.[7] At the time, loss of oat crop and herbicide expenditure was estimated to cost Canada $300 million annually.[8]
Mechanism
All flamprop variants are HRAC Group Z or 0, as the mode of action is classed as unknown. It is suspected to be the prevention of cell elongation at the meristematic regions.[1] Selectivity is possible because of differential metabolism, especially at the de-esterification, which is quicker in wild oats than in wheat and barley.[5]
Formulation
Flamprop formulations have long needed an oil based adjuvant for good performance.[2] Originally, this was 30 to 36% naphthenic and 9 to 25% aromatic compounds in an emulsifiable concentrate.[5] However, more adjuvant was needed than could be provided in concentrated formulations, so farmers were advised to add extra oil (sometimes sold as "Swirl"), though a 1994 study suggests the effect was small.[5] Nonylphenol ethoxylates and allylamine ethoxylates were tested, and were worse or approximately equal to Swirl. The best adjuvants were Genamin C050 and Dobanol 25-7.[5]
"Commando" was a 200 g/L formulation of flamprop-M-isopropyl.[5]
Variants
| Variant | CAS | Formula | Molar mass | Solubility |
|---|---|---|---|---|
| Flamprop | 58667-63-3 | C16H13ClFNO3 | 321.73 g/mol | |
| Flamprop-methyl | 52756-25-9 | C17H15ClFNO3 | 335.8 g/mol | 35 mg/L[4] |
| Flamprop-isopropyl | 52756-22-6 | C19H19ClFNO3 | 363.8 g/mol | 18 mg/L[4] |
| Flamprop-M-methyl | 63729-98-6 | C17H15ClFNO3 | 335.8 g/mol | |
| Flamprop-M-isopropyl | 63782-90-1 | C19H19ClFNO3 | 363.8 g/mol | |
| Flamprop-M | 90134-59-1 | C16H13ClFNO3 | 321.73 g/mol | |
| Flamprop-ethyl | 34029-27-1 | C18H17ClFNO3 | 349.8 g/mol | 13 mg/L[4] |
| Benzoylprop-ethyl | 34029-27-1 | C18H17ClFNO3 | 349.8 g/mol | 20 mg/L[4] |
Benzoylprop-ethyl is a closely related herbicide, which was studied in the same development program and first introduced in 1969, though it is now considered obsolete.[4]