The alkaline hydrolysis of ethyl 5-nitro-1-naphthoate, ethyl 6-nitro-1-naphthoate and ethyl 4:5-dinitro-1-naphthoate in ethanol-water (1956)
AuthorsMurdoch, J. D.show all
Ethyl 5-nitro-1-naphthoate, ethyl 6-nitro-1-naphthoate, and ethyl 4:5-dinitro-1-naphthoate have been prepared and the kinetics of the alkaline hydrolysis of each of these esters, in 85% ethanol (85:15 ethanol-water, by weight), have been studied over a range of temperatures. In following the kinetics of hydrolysis, a titration method has been used. Energies and entropies of activation for these hydrolysis reactions have been evaluated. Hammett substituent constants for a nitro group in the 4, 5 and 6 positions of 1-substituted naphthalene compounds, and the multiple substituent constant for two nitro groups, (in the 4 and 5 positions), have been calculated from the rate constants of the respective hydrolysis reactions. They have also been calculated from the pKa values of nitro-naphthylammonium ions which have previously been determined by another investigator. The general significance of values of activation energy and entropy, for the alkaline hydrolysis of nitro substituted ethyl 1-naphthoates, has been discussed together with a consideration of Hammett substituent constant for the nitro group in the naphthalene ring.