Flucarbazone- sodium

Stable in neutral to basic aqueous solution Unstable in acidic aqueous solution Flucarbazone-sodium is a post-emergent grass herbicide for use in winter wheat and spring wheat, including... 

The crop residue definition includes parent flucarbazone-sodium and the A/-desmethyl flucarba-zone metabolite (I). The soil and water residue definitions include parent flucarbazone-sodium and the sulfonic acid, sulfonamide and A/,0-dimethyl triazoli-none (NODT) metabolites... 

Wheat samples are extracted with dilute ammonia on the ASE200. The extracts are amended with isotopically labeled internal standards. The extracts are purified by sequential octadecyl reversed-phase solid-phase extraction (Cig SPE) and ethylenediamine-iV-propyl anion exchange (PSA) SPE. The samples are analyzed by LC/MS/MS. This method determines crop residues of flucarbazone-sodium and A-desmethyl flucarbazone with a limit of quantitation (LOQ) of 0.01 mgkg for each analyte. 

Data are collected for negative daughter ion transitions of m/z 395 to 128 and m/z 381 to 113 for the flucarbazone-sodium analyte and m/z 395 to 131 for the flucarbazone-sodium-ds internal standard... 

Note The LC/MS/MS system should be set up and tuned by a skilled operator for maximum sensitivity to flucarbazone-sodium and A-desmethyl flucarbazone... 

Because acceptable recoveries were obtained at O.Olmgkg", the method LOQ is 0.01 mg kg for flucarbazone-sodium and O.Olmgkg" for Af-desmethyl flucarbazone in all wheat samples. Linearity curves in both solvent and matrix blanks were mn from 0.005 to 0.100 mg kg . Because 0.005 mg kg of each analyte was reliably detected, the method limit of detection (LOD) was 0.005 mg kg in all wheat samples. 

Five replicate recoveries of flucarbazone-sodium, sulfonic acid, sulfonamide and NODT from soil fortified at 0.001 mgkg averaged 97, 90, 100 and 87%, respectively. Therefore, the LOQ is 0.001 mg kg for each analyte. 

R. Neri, Pharmacology and pharmacokinetics of flutamide. Urology 34 (1989) 19-21. R. Eliason, J.J. Schoenau, A.M. Szmigielski, W.M. Laverty, Phytotoxicity and persistence of flucarbazone-sodium in soil. Weed Sci. 52 (2004) 857-862. 

Nandula and Messersmith (2001) found that a wild oat accession with metabolism-based resistance to imazameth-abenz, an ALS inhibitor, was cross-resistant to flucarbazone-sodium (BAY MKH 6562). 

Another example found in herbicides is the ALS inhibitor flucarbazone-sodium (Everest ) [87]. This postemergence wheat herbicide controls grass weeds, as well as a number of broadleaf weeds of commercial significance. 

The first examples of the new herbicidal dass of sulfonylaminocarbonyl-triazolinones (SACTs) were reported in 1989 [1]. Following intensive chemical optimization two representatives were developed and commerdalized for selective weed control in cereals. In 2000, flucarbazone-sodium (1) was introduced in the Canadian market under the trade name Everest for the control of wild oats Avenafatua) and green foxtail Setaria viridis) in spring wheat Triticum aestivum) and durum wheat (Triticum durum) (Fig. 2.6.1). 

Table 2.6.1 Physicochemical properties of flucarbazone-sodium and propoxycarbazone-sodium.

The sulfonyl part 4 of flucarbazone-sodium (1) can be prepared by a classical Meerwein reaction from the aniline (5) prepared according to Refs. [24, 25] (Scheme 2.6.6). 

The flucarbazone-sodium intermediate (7) has long been known [27], but for safety reasons there was a great need for alternative procedures (Scheme 2.6.8) ... 

Flucarbazone-sodium (1) was discovered and developed by the former Plant Protection Division of Bayer AG (now Bayer CropScience) [40-42]. Since 2002 it is commercialized by Arysta lifeScdence in Canada and the USA under the trade name Everest [43] and in Chile as Vulcano . 

The exchange of the ortho-COOMe by the ortho-OC i residue in the sulfonylaryl unit of propoxycarbazone sodium (103 2001, Attribut , Bayer CropScience) [194] led to the systemic herbicide flucarbazone sodium (104 2000, Everest , Bayer CropScience) [195] (Fig. 35.25) (for more details see Chapter 2.6). 

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