The acid catalyzed hydrolysis of methyl isocyanide

Liew, Yu-Yuan Lim (1972) The acid catalyzed hydrolysis of methyl isocyanide. Masters thesis, Memorial University of Newfoundland.

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Abstract

The acid catalyzed hydrolysis of methyl isocyanide was studied as a function of temperature, pH, general acid concentration and buffer acid. The rate of disappearance of methyl isocyanide was followed by vapour phase chromatographic analysis. -- In the weakly acidic, buffered solutions (pH 4 to 6), the hydrolysis of methyl isocyanide to N-methylformamide is a reaction pseudo-first order in methyl isocyanide showing a small negative salt effect. The reaction shows a linear rate dependence on concentration of the general acid (un-ionized acid) at fixed pH and the rate of disappearance of methyl isocyanide increases with temperature. The activation energy is 16.19 ± 0.87 Kcal mole⁻¹. -- The observation of general acid catalysis supports a reaction mechanism with an initial formation of a hydrogen-bonded complex between the carbon atom of the isocyano group and the general acid, that is: -- [special characters omitted] -- Since water is the solvent (i.e. present in great excess), the rate expression is, -- Rate = ( k₂k₁/k₋₁ )(CH₃NC)(HA).

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