ABSTRACT
More than one hundred organophosphorus compounds are, or were, actually used as pesticides in the world. Millions of candidate compounds have been and will be synthesized. The variety of organic moieties in organophosphorus pesticide molecules is too great to discuss all of their synthetic methods. This chapter deals only with the principal reactions, involving the phosphorus moiety, which are generally useful for the preparation of organophosphorus pesticides. There were only a few practical insecticides of phosphate esters because of their relatively high toxicity and low stability, until the recent development of a unique class, phosphate esters of enols, the syntheses of which became easier by the finding of the Perkow reaction. Dialkyl phosphorochloridates react also with oximes and hydroxamic acids in the presence of acid binding agents or with their alkali metal salts, giving a new class of phosphate esters.
