Biomaterial Database

The hydrolysis of N-methylisatin: on how a simple rate-pH profile may mislead. 1994

M S Mirrlees, and P J Taylor

Zeneca Pharmaceuticals, Macclesfield, Cheshire.

Alkaline hydrolysis of the title isatin 4 in unbuffered solution obeys a rate law such that kobs varies; is directly proportional to [OH-]2 at pH 10 changes smoothly to kobs varies; is directly proportional to [OG-] by pH 13. As in the case of other isatins, this inflection in the pH profile is traced to ionisation of the substrate by addition of OH-; the UV spectrum of the anion has been recorded. Hydrolysis is also very sensitive to general base catalysis, which has mechanistic implications and would probably have prevented any development of this compound as a potential drug.

UI	MeSH Term	Description	Entries
D007211	Indoles	Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D013056	Spectrophotometry, Ultraviolet	Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Ultraviolet Spectrophotometry