A study of preparation methods for alpha-aminoalkanephosphonic, alpha-aminoalkanephosphonous and alpha-aminoalkanephosphinic acids has been made, based on the combined use of an aldehyde, an amino com pound, and a phosphorus reagent. Reported yields are frequently poor and the mechanisms of the reactions are unclear. The synthesis of alpha-aminoalkanephosphonic acids has been systematically examined. Propanal was used as a model carbonyl compound in reaction with various combinations of the following: 1) (PhO)3P, (PhO)2PH, (MeO)3P, (MeO)2PHO, (Et0)2PH0, PCI3, H3PO3. 2) H2NC02Et, H2NC02CH2Ph, H2NCH2Ph, H2NCHPh2, H2NCONH2 , H2NC0NHPh. NH3. The yields of various routes developed have ranged from 65% to 12%. The products have been fully characterised by melting point, elemental analysis, and nmr (1H,13C,31P) spectroscopy. Radiolabelled alpha-amino4 -[14C ]-propanophosphonic acid was prepared for toxicology studies. An interesting feature of this compound has been the formation of chemically identical crystalline products whose melting points differ by 10°C after repeated recrystallisation. The crystal structure of alpha-amino4-[14C]-propanephosphonic acid was determined in order to examine the possibility of different crystalline forms. 31P nmr spectroscopy studies of "one-pot" syntheses of the alpha-aminopropanephosphonic acid have shown that low yields may be due to the formation of several phosphorus-containing by-products and not merely from the problems of isolation. A range of a-aminoalkanephosphonous acids and their derivatives has been prepared and characterised by nmr (1H,13C, 31P) spectroscopy. These acids were also examined by FAB mass spectrometry and were found to give strong [M+H]+ ions. New derivatives of alpha-aminopropanephosphonic acid were prepared and characterised. Results of screening tests have been presented.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:293792 |
| Date | January 1989 |
| Creators | Bawa, Fatima |
| Publisher | London Metropolitan University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://repository.londonmet.ac.uk/3198/ |
Page generated in 0.002 seconds