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Cameron, David George (1983) The synthesis, structure and fungicidal activity of guanidinophosphonic acids and their aminophosphonic precursors. Doctoral thesis, Polytechnic of North London.
Alkanephosphonic acids of the classes a-amino, a-guanidino, a-(hydroxy)amino, a-thioureido, w-amino, and w-guanidino have been prepared, and also the u-amino and 10-guanidino types having aza substituents In positions 2 and 3 In the alkyl chain. The 1H, 13C, and 31p nmr spectroscopy of these compounds was examined in detail and the 13C nmr particularly useful for positive Identification of these phosphonic acids. The phosphorus-carbon coupling constants vary along the alkyl chain with 1jpcc = 130 -160 , 2Jpcc = 0-6 3Jpccc = 1 0-2 0 , and 3Jpcnc = 5-10 Hz. The spectra were recorded in solution in D2O and also in a mixture of D20/D2iS04 and from a comparison of these results it has been shown that these phosphonic acids exist as zwitterions in solution. The first crystal structures of guanidinoalkanephosphonic acids are reported for 1-guanidino- and 3-guanidino-propanephosphonic acid and have confirmed that these compounds are zwitterions In the solid state with each exhibiting a high degree of hydrogen-bonding.
The use of Fast Atom Bombardment mass spectrometry has useful for confirmation of molecular weight with the M+1 ion being the base peak in most cases. Also a number of Important fragmentations (such as the losses of H3P03, NH3, H2NCN) have been observed. The novel reaction of an alkylguanidine with a dialkyl phosphite In the Atherton-Todd reaction was found to be a useful method for phosphorylating dodecylguanldine.
In vivo and in vitro screening tests showed that in general all the phosphonic acids tested possessed fungicidal activity against Pyricularia oryzae. Rhizoctonia solani, Septoria nodorum. Botrytis clnerea, Dreschlera teres. Dreschlera sativa and Fusarium' avenaceum. l-Amlnopropanephosphonic acid and N-(10-guanidinodecyl)aminomethanephosphonic acid were found to have comparable fungicidal activity with the commercial fungicides Panoctine and Dodine.
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