Dialkyl trichloromethylphosphonate

Alkyl esters of phosphonous and phosphinous acid also react readily y with carbon tetrachloride, while analogous aryl esters, e.g., EtP(OPh)2, are resistant even at 160° (152,173). The reaction of bromotrichloro-methane with triethyl phosphite, which occurs smoothly at 80° to furnish dialkyl trichloromethylphosphonate in excellent yield (99%), is light catalyzed. Chloroform is unchanged in the presence of triethyl phosphite (98,156) even under drastic conditions, and diethyl dichloro-methylphosphonate is not produced unless a free radical initiator is present (118). 

Abstraction of positive halogen by trivalent phosphorus compounds represents an expeditious route for the synthesis of dialkyl l-(trimethylsilyl)methylphosphonates. Thus, treatment of diethyl trichloromethylphosphonate with hexamethylphosphorous triamide (HMPT) in the presence of McjSiCl in CgHg at room temperature affords diethyl l-(trimethylsilyl)-l,l-dichloromethylphos-phonate in 90% yield. Similarly, CCI4 and CICI3 have been reacted with trimethylsilylmethyl dialkyl phosphites. ... 

Other applications of dialkyl l-(trimethylsilyl)methylphosphonates include the reaction with dielec-trophihc reagents for the preparation of three-, four-, five-, and six-membered cycloalkylphospho-nates. Diethyl trichloromethylphosphonate is particularly well suited to this approach, and the exchange of the three halogen atoms with n-BuLi followed by sequential addition of Mc ,SiCl and (fl-dibromoalkanes results in the formation of a series of a-silylated cycloalkylphosphonates... 

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