Fukuto_1959_J.Am.Chem.Soc_81_372

A number of new ethyl p-nitrophenyl alkylphosphonates were prepared and the effect of the alkyl moiety on the lability of the phosphorus-0-p-nitrophenyl bond as measured by alkaline hydrolysis was examined. It was found that the rate of hydrolysis of these alkylphosphonates to p-nitrophenol and ethyl alkylphosphonic acid, in general, decreased with increase in alkyl chain length. Compared to the straight chain compounds, branching in the 1- and 2- positions greatly decreased the hydrolysis rate. The rate of reaction of these compounds with insect cholinesterase also was measured and compared with the hydrolysis rate. Many of these compounds showed high toxicity to the common housefly, Musca domestica L., and degree of toxicity was parallel to cholinesterase inhibition.