Thiophosphonates Phosphonothioates

Synonyms AI3-17798 BRN 2542580 Caswell No. 454 EINECS 218-276-8 ENT 17298 EPA pesticide chemical code 041801 EPN 300 ESA Ethoxy-4-nitrophenoxy phenylphosphine sulfide Ethyl p-nitrophenyl benzenethionophosphate Ethyl p-nitrophenyl benzenethio-phosphonate Ethyl p-nitrophenyl ester 0-Ethyl 0-4-nitrophenyl phenylphosphonothioate Ethyl jD-nitrophenyl phenylphosphonothioate 0-Ethyl 0-p-nitrophenyl phenylphosphonothioate Ethyl p-nitrophenyl thionobenzenephosphate Ethyl p-nitrophenyl thionobenzenephosphonate 0-Ethyl phenyl p-nitrophenyl phenylphosphorothioate Ethyl p-nitrophenyl thionobenzene phosphate 0-Ethyl phenyl p-nitrophenyl thiophosphonate MAPJ Meidon dust 15 NSC 8943 NSC 404840 OMS 219 Phenylphosphonothioic acid O ethyl O-p nitrophenyl ester Phosphonothioic acid, 0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl) ester PIN Santox. 

One of the procedures most widely used for the preparation of thiophosphonic and thiophosphinic acid derivatives is that of chalcogen exchange and, in particular, the replacement of the phosphoryl oxygen by sulphur, a step which is conveniently brought about by the action of hot P4S10, with the liberation of P4O10. A common application has been the conversion of phosphonic dichlorides into phosphonothioic dichlorides (equation and the similar conversion of phosphinic chlorides into phosphinothioic... 

The alkylation, with the more reactive of alkyl halides, of the sodium salts of monoes-terified phosphonothioic acids (equation 22) (see also Scheme 11) or of the disodium salts 107 results in preferential S-alkylation, and the same situation obtains for the salts of phosphinothioic acid " methylation can also be carried out with dimethyl sulphate. Alkylations may also be performed under phase-transfer conditions. From both practical and theoretical perspectives, the subject is more complex, since the course of alkylation reactions depends on the nature of the alkylating agent, on the polarity of solvent and whether this is protic or non-protic and on the concentrations of reactants a study of these features has been the subject of two reports In non-polar or weakly polar aprotic media, or in EtOH, alkylation occurs almost exclusively on sulphur, but in dipolar aprotic solvents, O-alkylation also takes place. The relative yields of sulphur- and oxygen-substituted derivatives, [Qs/Qol depends, for a given solvent, on the nature of substituents on phosphorus, i.e. essentially, whether the substrate is a thiophosphoric, thiophosphonic or thiophosphinic acid. With alkyl tosylates as alkylating agents at 0.02 m in hmpt, the alkylation of sodium 0,0-dialkyl or diphenyl phosphorothioates results in 100% overall conversions with [Qs/Qo] 5 the overall yields for sodium diphenyl- or diisopropyl-phosphinothioates are lower (50-100%) with [Qs/Qo] 1 ... 

The reaction between diastereoisomerictilly enriched samples of the thiophosphonic chloride (534) and isopropylamine or rm-butylamine ultimately affords the phosphonothioic diamides (536), and is thought to proceed through the... 

Thiohalides of the type RP(S)X2 and R2P(S)X can be made by heating sulphur with the corresponding phosphonous or phosphinous halides. Phosphonothioic (thiophosphonic) halides can be obtained by the action of hydrogen sulphide on tetrachlorophosphoranes (9.425), or phosphonous halide-aluminium trichloride complex (Chapter 6), or P4SJ0 on the corresponding phosphonic dihalide (9.426), or by reaction (9.427) in which PSCI3 acts as a sulphur donor. Monophenyl phosphine and thionyl chloride produce phenyl phosphonothionic dichloride, which can also be obtained by thermal isomerisation (9.428). 

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