Thiophosphoric acid derivatives

As is unfortunately true for many investigations, the studies reflected by die data shown in Fig. 13.18 did not include analysis for transformation products. Therefore, we may only speculate regarding reaction mechanisms. Nevertheless, we may conclude that when dealing with the hydrolysis of phosphoric and thiophosphoric acid derivatives, as well as with other phosphorus-containing hydrolyzable functionalities (see Fig. 13.19), one has to be aware that various reaction mechanisms may apply. Consequently, depending on the environmental conditions prevailing, product distribution, at least with respect to intermediates formed, may vary considerably. 

Only a few papers dealing with monocyclic 1,2,3-triazines have been published, and the number of known compounds of this type is still low. Much more information is available on the 1,2,3-benzotriazines (2) and the first representative of this class was prepared in the last century (1887JPR(35)262>. The increasing interest in the chemistry of (2) is a result of the wide range of biological activity associated with many derivatives of 1,2,3-benzotriazin-4-(3//)-one (3 R=H), and especially of phosphoric and thiophosphoric acid derivatives of (3). 

Thiophosphoric Acid Derivatives. A fortunate combination of characteristics occurs in the phosphoric acid derivatives upon substitution of a sulfur atom for one of the oxygens of the parent compound Namely, the toxicity of the derivatives to higher forms of life is substantially diminished. while at the same rime, (he acaricidal and insecticidal powers, with... 

Let us now turn to an example of nucleophilic substitution involving a group of pollutants other than alkyl halides. We consider the hydrolysis of thiometon and disulfoton, two insecticides that were among the major contaminants that entered the Rhine River after the famous accident at Schweizerhalle in Switzerland in 1986 (Capel et al., 1988). This example is representative for the hydrolysis of a variety of phosphoric and thiophosphoric acid derivatives (e.g., esters, thioesters, see Fig. 1), and it illustrates that hydrolysis of a more complex molecule may be somewhat more complicated. The kinetic data, as well as the proposed mechanisms of hydrolysis of thiometon and disulfoton, are presented in Table 4 and Figure 2, respectively. In these cases, the base catalyzed reaction... 

Parathion-methyl is less toxic to humans than the ethyl homologue. This is in agreement with the general experience that dimethyl phosphoric acid and dimethyl thiophosphoric acid derivatives are less toxic to warm-blooded animals than the... 

It is assumed that the hydrogen bromide released on the oxidation of thiophosphoric acid insecticides with N-bromosuccinimide or bromine vapors forms intensely fluorescent salt-like derivatives with 3-hydroxyflavones — such as robinetin [1, 2, 4]. 

Chlorothietane was subjected to reaction with dichloro derivatives of phosphorous acid to give, after heating the reaction mixture to 150°C, the acyclic compound thiophosphoric acid in low yields. ... 

Ammonia derivatives of thiophosphoric acid, PS(OH)3, have been reported in which the hydroxyl groups are replaced one by one by the amido-radicle thus ... 

Aoids (709) 69. Imidodiphosphoric or Imidopyropbosphoric Aoid (712) 70. Amides and Imides of the Higher Phosphoric Acids (714) 71. The Meta-phosphimic Acids and their Salts (716) 72. Phosphorus Chloronitrides or Phosphonitrilic Chlorides (721) 73. Ammonia Derivatives of Thiophosphoric Acid (725). 

Phosphorus containing additives include esters of phosphoric acids, derivatives of thiophosphoric acids, phosphites (Davey, 1950 Sakuri and Sato, 1970), and the metal salts of dithiophosphoric acid diesters, the best known of these compounds being the ZDDPs. The structure of ZDDP films, the composition of the film formed, and the mechanism of action on the molecular level are summarized in Chapter 4. 

Thiophosphites.—These salts may be regarded as derived from mono-, H3PS02, di-, H3PS20, and tri-thiophosphorous acids, H3PS3. They were prepared, with other products, by heating metals with a mixture of sulphur and phosphorus, e.g. AgsPS3, or metallic sulphides... 

Amido-derivatives of Phosphorous and Orthopbosphoric Acids—Amido- and Imido-derivatives of Metaphosphoric Acid.—Amides and Imides of Condensed Phosphoric Acids—Nitrilophosphoric Acids—Amido-, Imido- and Nitrilo-thiophosphoric Acids—Phosphorus Halonitrides or Amidohalides— Phosphorus Nitride. 

In the acid-catalyzed thiolysis of nitriles (73) HaS is commonly replaced by appropriate precursors or equivalents. Thus, thioacids, RCOSH, have been used together with HC1 or SnCU. Thioacetamide (77) is a very convenient source of HaS as shown in equation (36), an equilibrium is established which is shifted to the right, if the liberated MeCN is removed by distillation. Alternative sources of HaS are di-thiophosphoric, HSP(=S) (OR)a with R = Et or Pr, " or phosphinodithioic acid derivatives, HSPPha(= S). ° The last mentioned approach allows the elegant synthesis of a-hydroxythioamides (78) in Scheme 11. ... 

Derivation From diethyl maleate and dimethyldi-thiophosphoric acid. 

Compounds with phosphorus as the key element that have been investigated for extreme-pressure additive activity add up to an impressively long list. But only a few of them have turned out to be of practical utility and these are predominantly esters of phosphoric acid or derivatives of thiophosphoric acid. In this section we shall be concerned only with those compounds in which phosphorus in combination with oxygen constitutes the key structure dithiophosphates and related derivatives are discussed in Section 11.2.6. The four main types of phosphorus oxyacid esters treated in the present section are shown in Table 11-12. Phosphoric and phosphorous acids are trifunctional hence there are three or-ganophosphorus structures to be considered the neutral triester, the monoacidic diester and the diacidic monoester. 

Phosphorus Compounds.—Treatment of the dioxaphospholen (635) with sulphur yields a mixture of the oxathiole (636) and fran -dibenzoylstilbene, PhCOCPh=CPhCOPh." 2-Phenyl-l,3,2-dioxaphospholan (637 R = Ph) dimerizes in solution to a ten-membered-ring compound, which was isolated as (638) by sulphurization." The cyclic thiophosphorous acid (639) exists in equilibrium with the betaine (640) in aqueous ethanol/ The spiro-compound (641), which contains a phosphorus-hydrogen bond, is formed by the action of (637 R = Cl) on diethyl tartrate. The phosphazene (642) spontaneously cyclizes to the spiro-compound (643). " Stable derivatives (645) and (646 R = Br) of five-co-ordinate phosphorus have been obtained by the action of bromine on the o-phenylene phosphite (644)/ The chlorine analogue (646 R Cl) reacts with 3,5-dimethylpyrazole to give the corresponding pyrazole derivative (646 R = 3,5-dimethylpyrazol-l-yl), which reversibly dimerizes to the zwitterion (647). ... 

Gerrard, W., and Hudson, H. R., Organic Derivatives of Phosphorous Acid and Thiophosphorous Acid, in Organic Phosphorus Compounds, Vol. 5, Kosolapoff, G. M., and Maier, L., eds., 1973, 23-329, Wiley, New York. 

The N-phosphorylated derivatives of pyrrolidine 134 [125, 126], 2-methoxymethylpyrrolidine 135 [127], and 2-ethoxycarbonylpyrrolidine 136 [128] are formed during the reaction of the corresponding heterocycles with mono- and dichlorides of phosphoric, phosphonic, thiophosphoric, and thiophosphonic acids ... 

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