5 - methylphosphonothioate

Differences in chirality of substrate, and nature of solvent, have no effect on the competitive nature of the displacement of 0-alkyl and S-methyl groups in the reactions between (+)-pinacolyl alkoxide and 0-ethyl (and methyl) S-methyl methylphosphonothioates (Scheme 23). For the (R)-( + ) esters, e.g. (210), the displacements are highly stereoselective and occur with configurational inversion,but the enantiomeric esters do not display such stereoselectivity. (-)-Menthol might be considered a mirror image of (S)-pinacol, and similar reactions with the sodium salt of (-)-menthol occur highly stereoselectively... 

Nerve agents, which interfere with nerve signaling such as Sarin (GB), Soman (GD), Tabun (GA), or methylphosphonothioic acid, S-[2-diethylamino)ethyl]0-2-methylpropyl ester (VX). 

Brown, D.F., A.J. Policastro, W.E. Dunn, R. A. Carhart, M. A. Lazaro, W. A. Freeman, and M. Krumpolc. Development of the Table of Initial Isolation and Protective Action Distances for the 2000 Emergency Response Guidebook, Argonne National Laboratory Report No. ANL/DIS-00-1. October 2000. Buckles, L.C. and S.M. Lewis. "S-(2-Diisopropylamino-ethyl)0-ethyl methylphosphonothioate Stabilized with Soluble Carbodiimides," United States Patent 4012464, September 24,1965. Centers for Disease Control and Prevention. "Case Definition Nerve Agents or Organophosphates." March 15,2005. 

Ethyl Hydrogen Methylphosphonothioate 0-Ethyl Hydrogen Methylphosphonothionate O-Ethyl Methylphosphonothioate O-Ethyl Methylphosphonothioic Acid O-Ethyl Methylthiophosphonate... 

O-Ethyl S-2-(Triethylammonium)ethyl Methylphosphonothiolate Iodide O-Ethyl S-2-(Trimethylammonium)ethyl Ethylphosphonothiolate Iodide O-Ethyl S-Ethyl Methylphosphonothioate... 

When thionophosphonic esters are used for conversion to the phosphonothiochloridates, observation of the stereospecificities of the reactions is possible. Alternative results may be attained through judicious choice of the reagent system. For example, the optically active O-isopropyl methylphosphonothioate, as shown in Equation 4.10, reacts with phosgene at sulfur only to form the O-isopropyl methylphosphonochloridate with inversion of configuration at phosphorus.20... 

Phosphonothioic acid, methyl-, S-(2-bis(l-methylethylamino)ethyl) 0-ethyl ester O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothiolate S-2-Diisopropylaminoethyl O-ethyl methylphosphonothioate S-2((2-Diisopropylamino)ethyl) O-ethyl methylphosphonothiolate O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate O-ethyl S-(2-diisopropylaminoethyl) methylthiolphosphonoate S-(2-diisopropylaminoethyl) o-ethyl methyl phosphonothiolate Ethyl-S-dimethylaminoethyl methylphosphonothiolate VX EA 1701 TX60... 

Improvised explosive mixture Improvised explosive mixture Improvised ANFO Improvised explosive mixture Sub-VX,S-(2-dimethylaminomethyl)-o-ethyl methylphosphonothiolate, o-ethyl S- [2- (dlmethylamino )methyl] -methylphosphonothioate Inositol hexanitrate... 

Trivinylarsenic, Tris(vinyl)arsine TX-60, Methylphosphonothioic acid S-[2-[bis(l-methylethyl)amino]ethyl] o-ethyl ester... 

IIVX, 18, 45, 97, 117-118, 166, 215. See also Sub-VX,S- (2-dimethylaminomethyl)-o-ethyl methylphosphonothiolate, o-ethyl S- [2- (dimethylamino)methyl] -methylphosphonothioate Impact-sensitive material, 3, 23, 30, 45 6, 72, 116-117, 122, 136, 164 Improvised ANFO, 17-18 Improvised explosive, 19, 72, 164 Improvised explosive device, 183 Improvised explosive mixture, 17-18, 20, 22 Improvised military propellant, 27, 118, 140, 164 Improvised projectile propellant, 51, 71, 80, 152, 164... 

Once chemical agents are fully dispersed, they do not tend to persist in the environment because of their high chemical reactivity, particularly with water (hydrolysis). However, in extremely dry desert climates, they can persist for considerable periods of time (U.S. Army, 1988). The major environmental degradation products of nerve and mustard agents have recently been assessed and their persistence and toxicity evaluated. A potential hydrolysis product of VX (S-(2-diisopropylaminoethyl) methylphosphonothioic acid [EA-2192]) is a degradation product expected to display a high level of mammalian toxicity. Some mustard partial hydrolysis products are also toxic (Munro et al., 1999). 

The methanolyses of several phosphate/phosphonate esters and their thio analogues [e.g. 0,0-diethyl 0-(4-nitrophenyl) phosphate, paraoxon (101 X = O, Z = 4-N02), 0,0-diethyl S- S-dichlorophenyl) phosphorothioate, (102 R = OEt), and 0-ethyl S-OA-dichlorophenyl) methylphosphonothioate (102 R = Me)] catalysed by methoxide and the complex of Zn2+ (MeO-) with 1,5,9-triazacyclododecane (79 M = Zn) were studied in methanol at 25 °C. The reaction of methoxide and (79 M = Zn) with the entire series of esters appears to adhere to a common mechanism that involves pre-equilibrium binding of the substrate, followed by intramolecular attack of the coordinated methoxide concerted with OAr or SAr leaving group departure.79... 

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