181259-72-3Relevant academic research and scientific papers
The preparation and characterization of some fluorinated α-aminoarylmethanephosphonic acids
Green, Donovan St C.,Gruss, Ulrike,Haegele, Gerhard,Hudson, Harry R.,Lindblom, Lars,Pianka, Max
, p. 179 - 207 (2007/10/03)
α-Aminoarylmethanephosphonic acids have been prepared with a range of fluoro, fluoroalkyl, or fluoroalkoxy substituents in the benzene ring (4-F, 3-F, 2-F, 3,4-F2, F5, 4-CF3, 3-CF3, 4-CF3O, and 3-CF3O). These compounds have relatively low aqueous solubility and their NMR spectra (1H, 13C, 31P and 19F) were therefore recorded in D2O in the presence of an excess of alkali. Under these conditions, the ring substituents appear to have little effect on δp (15-18 ppm), or on the 1H and 13C parameters for the benzylic group (α-CH), which are mainly in the ranges observed for other types of α-aminoarylmethanephosphonic acids under alkaline conditions (δH 3.8-4.0 ppm, 2JPH 15.3-16.5 Hz; δC 57-58 ppm, 1JPC 128-132 Hz). For those examples with fluorine in the ortho position (i.e., the 2-fluoro and pentafluoro derivatives) a slightly higher field chemical shift was observed for the benzylic carbon atom (δC 50-51 ppm). In the fast-atom bombardment mass spectra, pseudo-molecular ions, MH+, and ions resulting from the elimination of phosphorous acid [MH - H3PO3]+, provide a further useful means of chararacterization for these compounds. Key words: Fluorinated aminoarylmethanephosphonic acids, dialkyl N-diphenylmethylaminoaryl-methanephosphonates, NMR spectroscopy, FAB mass spectrometry.
