The hydrolysis of diethyl 8-dimethylaminonaphthyl-1-phosphate is catalysed by the neighbouring dimethylammonium group, with a rate acceleration, compared with diethyl naphthyl-1-phosphate, of almost 106. The effective pKa of the naphtholate leaving group is reduced from 9.4 to 3.4 by partial protonation in the transition state. The reaction is catalysed by oxyanion nucleophiles, and it is shown that a common nucleophilic mechanism, ...