Max Pianka

ORGANOPHOSPHORUS COMPOUNDS AS POTENTIAL FUNGICIDES. PART II. AMINOALKANE-, GUANIDINOALKANE-, AND THIOUREIDOALKANE-PHOSPHONIC ACIDS: PREPARATION, SPECTROSCOPY, AND FUNGICIDAL ACTIVITY

Abstract A range of α-amino-, ω-amino-, α-guanidino-, and ω-guanidinoalkanephosphonic acids has been prepared for the purpose of studying their spectroscopic features and fungicidal activity. In addition, α-thioureido-octanephosphonic acid and thioureylene-1,1-bis(1-octanephosphonic acid) were isolated during the preparation of α-guanidino-octanephosphonic acid. 31P, 1H, and 13C nmr spectral data which were obtained for solutions of the amino-and guanidino-compounds in D2O or D2O/D2SO4, and for the thioureido compounds in DMSO-d 6, are discussed together with previously reported data for the aminophosphonic types. FAB mass spectrometry generally gives strong pseudomolecular ions [MH]+ for the zwitterionic amino-and guanidino-compounds with relatively simple fragmentations. Fungicidal activity of the α-aminophosphonic acids was found to be greater than for the ω-amino compounds, with maximum activity at a chain length of three carbon atoms when used as a seed dressing for the control of Drechslera spp. Mod...

Transition metal complexes of dialkyl α-hydroxyiminophosphonates, a novel class of metal complexes

A new range of dialkyl α-hydroxyiminophosphonates has been prepared and the first examples of metal complexes of this class of compound have been obtained; X-ray crystal structure analysis of the dichlorobis(diethyl E-(α)-hydroxyiminopropanephosphonate)nickel(II) complex shows a distorted octahedral coordination at the nickel atom giving two symmetry related diethyl-(E)-α-hydroxyiminopropanephosphonate ligands and two chlorine donors.

THE PREPARATION AND CHARACTERIZATION OF SOME FLUORINATED α-AMINOARYLMETHANEPHOSPHONIC ACIDS

Abstract 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 δH (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, 2 J PH 15.3–16.5 Hz; δc 57–58 ppm, 1 J PC 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 result...

ORGANOPHOSPHORUS COMPOUNDS AS POTENTIAL FUNGICIDES. PART VI.1 PREPARATION, CHARACTERIZATION, AND BIOLOGICAL ACTIVITY OF ANALOGUES AND DERIVATIVES OF 1-AMINOPROPANEPHOSPHONIC ACID

Abstract α-Aminopropane-phosphonous,-methylphosphinic, and-phenylphosphinic acids do not exhibit comparable antifungal activity to that shown by α-aminopropanephosphonic acid (ampropylfos) against Drechslera teres, when applied as seed dressings. It is concluded that the phosphonic acid function is necessary for this type of activity. Moderate activity against several organisms was nevertheless shown by α-aminopropane-and α-aminoethane-phosphonous acids in foliar spray tests, although longer chain compounds were found to be inactive, α-Ureidopropanephosphonate (ammonium salt) also showed activity in foliar tests at 1000 ppm. A range of new ureylene-and thioureylene-bisphosphonates, prepared as potential profungicides of ampropylfos, proved to be inactive as seed dressings although tetrakis(2,2,2-trifluoroethyl) thioureylenebis(1-propylphosphonate) gave 75–100% control of Puccinia recondita as a foliar spray (1000 ppm). Characterization of the various compounds by nmr spectroscopy and mass spectrometry is discussed.

ORGANOPHOSPHORUS COMPOUNDS AS POTENTIAL FUNGICIDES. PART I. N-(ω-GUANI-DINOALKYL)AMINOALKANEPHOSPHONIC ACIDS AND THEIR AMINOPHOSPHONIC PRECURSORS: PREPARATION, NMR SPECTROSCOPY, AND FAST ATOM BOMBARDMENT MASS SPECTROMETRY

Abstract N-(ω-Aminoalkyl)- and N-(ω-guanidinoalkyl)-aminoalkanephosphonic acids have been prepared from α, ω-diaminoalkanes by reaction with chloromethanephosphonic acid (or an ester of a halogeno-alkanephosphonic acid), followed by treatment with S-methylisothiouronium chloride. Ethylene diamine yielded 1-phosphonomethyl-2-iminoimidazolidine. A number of 1:1 salts of the α, ω-diamines and chloromethanephosphonic acid are also reported. Doubly charged zwitterionic structures are assigned to both ω-amino and ω-guanidino compounds on the basis of 31P and 13C nmr data. Thus the addition of an excess of acid (D2SO4) causes the 31P chemical shift to move to higher field, from ca. 8 to 14 ppm, whilst 1 Jpc increases from ca. 130 to 150 Hz. The 1H and 13C chemical shifts of the terminal methylene groups in the polymethylene chain are unaffected by acidification. Fast atom bombardment mass spectrometry gives rise to characteristic [M + H]+ ions, frequently as the base peak, and to fragmentations involving the los...

ORGANOPHOSPHORUS COMPOUNDS AS POTENTIAL FUNGICIDES. PART III.1 PEPTIDE DERIVATIVES OF α-AMINOPROPANEPHOSPHONIC ACID

Abstract Di- and tri-peptides with α -aminopropanephosphonic acid as the acid-terminal residue have been prepared containing L-alanyl, D-alanyl, DL-alanyl, and glycyl groups. Nmr parameters (1H, 13C and 31P) are reported for solutions of the peptides in D2O and are discussed. Diastereoisomeric forms of the L-ala-, and L-ala-L-ala-peptides were separated on a cation exchange-column and it was found in each case that the methine and carbonyl groups of the alanyl residue that is adjacent to the aminophosphonic group exhibit slightly different 13C chemical shifts in each of the two diastereoisomers. Fast-atom bombardment mass spectrometry gave characteristic [MH]+ ions, which usually appeared as the base peak. Fragment ions were formed by the elimination of α-lactam units from the amino-carboxylic acid residues and phosphorous acid from the aminophosphonic acid residue. The L-ala-peptides showed similar activity to that of α-aminopropanephosphonic acid when applied as seed-dressings at 400 ppm for the control...

ORGANOSULFUR COMPOUNDS AS POTENTIAL FUNGICIDES: THE PREPARATION AND PROPERTIES OF SOME SUBSTITUTED BENZYL 2-HYDROXYETHYL OLIGOSULFIDES

Abstract Compounds of the general type ArCH2SnCH2CH2OH (n = 1–4, Ar = Ph. 2-MeC6H4, 4-MeC6H4, 4-ClC6H4, 4-MeOC6H4; n = 1–3, Ar = 2-ClC6H4; n =2 Ar = 4-FC6H4; n =3 or 4, Ar = 2-furyl) have been prepared as analogues of the trisulfide PhCH2SSSCH2CH2OH antimicrobial compound which occurs in the plant Petiveria alliacea) and their potential application as agricultural fungicides has been examined. In vitro tests against Fusarium culmorum, Fusarium oxysporum and Gauenomyceles graminis showed that all compounds gave > 80% control of these organisms at 1000 ppm. Tests at 100 and 10 ppm showed varying levels of control but the activity did not depend significantly on the number of sulfur atoms present. Selected compounds were also shown to be active in vivo against Erysiphe graminis on barley seedlings, Borrytis fabae and Uromyces viciae-fabae on bean seedlings, Podosphaera leucorricha on apple seedlings, and Phytophthora infestans on potato leaf. The compounds were phytotoxic at concentrations greater than 0.33%.

The Preparation and Properties of Some α-Acyloxy- and α-Carbamoyloxy-Phosphonothionates

New f -acyloxy and f -carbamoyloxy derivatives of dimethyl 2,2,2-trichloroethyl-phosphonothionate have been prepared, characterized, and screened for activity against free-living soil nematodes. Several of the more easily hydrolysable esters, and also the N -methylcarbamoyl derivative, were as active as the parent pesticide, dimethyl f -hydroxy-2,2,2-trichloroethylphosphonothionate, after an induction period during which the active species is assumed to be released in vivo . It is concluded that the 2,2,2-trichloroethyl group is essential for activity in compounds of these types and that the presence of the N -methylcarbamoyl group does not in itself confer activity.

An Approach to the Development of Organophosphorus Fungicides

Abstract Phosphoramidates, phosphorodiamidates, phosphoric triamides, aminophosphonic acids, guanidinophosphonic acids, and phosphonopeptides are discussed as fungicides with potential for application in agriculture.

Identificação dos principais componentes do fungicida guazatine através da cromatografia a gás e cromatografia a gás acoplada com espectrometria de massas

Hexafluoroacetylaceton derivatives of some synthesized components of the guazatine fungicide were prepared, and their separation and identification performed through gas chromatography and gas chromatography-mass spectrometry. The chromatogram obtained from hexafluoroacetylacetone derivative of the commercial guazatine presented 14 major peaks, and 9 of them were identified through both techniques mentioned above.