Rate coefficients have been measured for the alkaline hydrolysis of 2-formylbenzonitrile 1, N-(2-formyl and -acetylphenyl)acetamides 2, N-(2-formylphenyl)-3-substituted benzamides 3,4-(2-formylbenzoyl)morpholine 4, 3-(4-morpholino)-and -(N-methylanilino)-phthalides 5 and -naphthalides 6 in 70% (v/v) dioxane-water at various temperatures. The enthalpies and entropies of activation have been evaluated. The hydrolysis of the nitrile is second order in base and that of the amides is first order in base. The relative rates of hydrolysis, activation parameters and substituent effects have been used to suggest the mechanisms of the reactions. Intramolecular catalysis by the neighbouring carbonyl group occurs in the alkaline hydrolysis of 1-4. The alkaline hydrolysis of 5 and 6 is rapid due to their lactone structures.

Ring-chain tautomerism inN-methyl-and N-(substituted phenyl)-2-formylbenzamides, 2-benzoylbenzamides, 8-formyl-1-naphthamides, 8-benzoyl-1-naphthamides and 5-formyl-4phenanthramides has been investigated by IR and 1 H NMR spectroscopy and the measurement of their pK a values in 30% (v/v) dimethyl sulfoxide-water. The tautomeric pair synthesised, i.e. hydroxylactamacylamide or aminolactone-iminocarboxylic acid, appears to be a function of the method of preparation and/or the basicity of amine used. The cyclic tautomer, i.e. hydroxylactam or aminolactone, is predominant in all cases studied. However, equilibrium constants have been estimated from the pK a values for aminolactone-iminocarboxylic acid tautomerisation in which the effect of the links follow similar trends as found for the corresponding hydroxylactone-acylcarboxylic acid tautomeric systems.

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chemical equilibria, complexation equilibria chemical equilibria, complexation equilibria L 5000 19 -025 Ring-Chain Tautomerism. Part 9. 2-Acylbenzamides, 8-Acyl-1naphthamides and 5-Acyl-4-phenanthramides -[such as (I)-(IV) (28 examples); pKa values]. -(BOWDEN, K.; HISCOCKS, S. P.; PERJESSY, A.; J. Chem. Soc., Perkin Trans. 2 [old] (1998) 2, 291-295; Dep. Chem. Biol. Chem., Univ. Essex, Colchester, Essex CO4 3SQ, UK; EN)

Reactions of Carbonyl Compounds in Basic Solutions. Part 28. The Alkaline Hydrolysis of 2-Formylbenzonitrile, N-(2-Formyl and -Acetylphenyl)acetamides, N-(2-Formylphenyl)-Substituted Benzamides, 4-( 2-Formylbenzoyl)morpholine, 3-(4-Morpholino)-and -(N-Methylanilino)-phthalides and -naphthalides.-Relative rates, activation parameters and substituent effects of the alkaline hydrolysis of title compounds are evaluated to propose a reaction mechanism. -(BOWDEN, K.; HISCOCKS, S. P.; REDDY, M. K.; J.