Phenyl diethyl phosphate

Biological activities also may correlate with electronic substituent factors alone, eg, the inhibition of acetylcholinesterase by six diethyl phenyl phosphates (36) gave r = 0.95 for... 

Schrader prepared the ester (38) in 60% yield by reaction of sodium p-nitrophenate with diethyl chlorophosphate, using xylene as solvent for the reaction. He made it, but in lower yields, from p-nitrophenol and diethyl chlorophosphate, using, respectively, pyridine and sodium cyanide as acceptors for hydrogen chloride. Schrader also prepared it in 96% yield by nitrating diethyl phenyl phosphate at 0° C. or below. Under the conditions he used, Schrader claims that the nitro group is directed to the para position. No yield is given for the diethyl phenyl phosphate, which he presumably made from sodium phenate and diethyl chlorophosphate. Diethyl chlorophosphate may be prepared in high yield (30) from diethyl phosphite and chlorine. 

It can also be made by nitrating diethyl phenyl phosphate below 0°. It is a red oil, almost insoluble in water, and Schrader found it effective against aphids, while Ball and Allen1 proved it active against the housefly, milkweed bug and cockroach. Later work showed it active against the two-spotted spider mite. 

Nitration of diethyl AT-phenylphosphoramidate and diethyl phenyl phosphate in acetic anhydride or sulphuric acid yields considerable amounts of the m-nitro-... 

Reaction of both methyl phenyl sulphone and diphenyl sulphone with potasium in liquid ammonia [24] leads to the formation of a dianion, which cleaves to give CfiHs, isolated as benzene. The initial electron transfer cannot be dissociative, as was the case for diethyl phenyl phosphate (p. 163), since the phenyl c-radical is not detected. The radical-anions from these sulphones have sufficiently long lifetime in liquid annmonia to allow reaction with a further electron. 

It is commonly assumed that the base-catalyzed hydrolysis of substituted dialkyl (i.e., dimethyl or diethyl) phenyl phosphates occurs by nucleophilic attack of OH" at the phosphorus with the phenolate being the leaving group (see also Section 13.4) ... 

Second-Order Rates Constants, kB, and pKia Values of the Phenol Moieties for a Series of Monosubstituted Diethyl Phenyl Phosphates at 25°C... 

The insecticidal activity of diethyl phenyl phosphates (Fig. 9.11) is one of the few examples where activity is related to electronic factors alone ... 

Figure 5.5 shows the relationship between hydrolyzability and anticholinesterase activity for seven substituted diethyl phenyl phosphates. The hydrolysis constants were determined in a buffer of pH 7.6 at 37°C and have the unit min-1. 

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