Organo-thiophosphates

Figure 3. Chromatogram of organo-thiophosphates using Tracor 550 gas chromatography equipped with flame photomeric detector specific for phosphorous (A)...

Singh, A.K., Jiang, Y. (2003). Lipopolysaccharide (LPS) induced activation of the immune system in control rats and rats chronically exposed to a low level of the organo-thiophosphate insecticide, acephate. Toxicol. Ind. Health 19 93-108. 

The author hopes that this chapter has convinced the readers of the value of homogeneous catalysis for the synthesis of organophosphorus compounds and for organo-heteroatom compounds in a broader sense. Hydrosilylation and hydroboration are indispensable modern synthetic reactions in this category. The H-P addition reactions herein described joins them as a third member. Although this chapter does not cover, the addition reactions of the S-P and Se-P bonds in thiophosphates [39] and selenophosphates [40] to alkynes also proceed in the presence of transition metal catalysts. In view of the wide use of phosphorus compounds, the new procedures will find practical applications. 

Triisooctyl thiophosphate [30108-39-5] M 450.6. Purify the ester by passing its solution in CCI4 through a column of activated alumina. [See Ailman Magean in Organo Phosphorus Compound (Kosolapoff Maier eds) Wiley Vol 7 pp 487-465 1973, and tri-p-tolyl phosphate below.]... 

Parathion and Paraoxon. Again, this represents a reaction (the sulfur oxidation of a thiophosphate pesticide) that is familiar to most in the pesticide area. Unlike heptachlor epoxide, paraoxon is not a stable compound and its actual presence in a poisoned animal was very difficult to demonstrate. The oxons of other organo-phosphorothioates are not so elusive. In any event, the paraoxon metabolite is an excellent example of where an understanding of metabolic processes and their potential toxicological significance alerted scientists to the likelihood that such a metabolite existed. Many years of work with similar compounds had established that the insecticidal thiophosphates required oxidation to the P=0 form in order to inhibit the neurotrasmitter acetylcholinesterase, the biochemical basis of their toxic action. Paraoxon was eventually isolated in vivo and now consideration of the oxon is a vital part of the overall risk assessment of this group of pesticides. 

---