Synthesis of Dimethyl Derivatives of Imidazolinone Herbicides: Their Use in Efficient Gas Chromatographic Methods for the Determination of These Herbicides

The dimethyl derivatives of imazaquin, imazapyr, imazmethapyr, imazethapyr, 2-[4,5 dihydro-1,4-dimethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methoxymethyl-3-pyridine carboxylic acid, 2-[4,5-dihydro-1,4 -dimethyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-4-methyl benzoic acid, and 2-[4,5-dihydro-1,4-dimethyl-4-(1-methyl ethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl benzoic acid were prepared and fully characterized. The availability of these derivatives has led to the development of efficient and multiresidue gas chromatographic methods for trace level analysis of imidazolinone herbicides in matrixes such as water, soybean, and soil. Keywords: Imidazolinone herbicides; dimethyl derivatives; gas chromatography; mass spectrometry; NMR spectroscopy