Distinguishing between N-methylated imidazolinones using mass spectrometry

✍ Scribed by Stanley J. Cardaciotto; Patrick C. Mowery; Michael L. Thomson; Richard S. Wayne

• Book ID: 102558648
• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 319 KB
• Volume: 22
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210220607

✦ Synopsis

Imidazolin-4-ones are a new class of herbicides which contain both an amide and amino nitrogen in a five-membered ring. During the manufacturing process, it is possible to methylate either nitrogen. This presented an interesting analytical problem in distinguishing between the two N-methylated derivatives of ASSERT@ (a mixture of 6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl~mand p-toluic acid methyl esters) at low levels in a complex mixture. After developing a high-performance liquid chromatography method for separating and isolating components in the mixture, mass spectrometric techniques, which included electron impact (EI) and collisional activation decomposition (CAD), were used to distinguish between two isomeric N-methylated derivatives. The data from the EB and CAD experiments enabled amidomethyl and aminomethyl structures to be assigned. Accurate mass measurements and proton nuclear magnetic resonance spectroscopy were used to support the assignments. thesis in plants. ASSERT is a selective herbicide for weeds in wheat and barley.' The registration of these