New syntheses of 1-chloroalkylphosphinates

Abstract

Different approaches to the synthesis of 1-chloroalkylphosphinates are described. Initially, we tried to extend a reaction described by Kabachnik for the preparation of chloromethylphosphinic acid chlorides [R¹(Cl)P(O)CH₂Cl] to C-substituted derivatives. We also considered the possibility of synthesizing the title compounds by routes already described for the formation of diethyl 1-chloroalkylphosphonates. Although these methods have allowed us to obtain several of the desired phosphinates, they suffer from limitations that restrict their synthetic applications. Finally, we have developed a more general approach that allows the formation of a wide range of phosphinates. It involves a selective P–C bond formation by reaction of MeMgCl and PhMgCl with phosphonochloridates, which are prepared by P-chlorination of 1-chloroalkylphosphonates.