Collect. Czech. Chem. Commun. 1997, 62, 1562-1576

Dissociation of Amides in Strongly Basic Medium of Sodium Methoxide in Dimethyl Sulfoxide-Methanol Mixtures

Petr Mitaš, Jaromír Kaválek and Oldřich Pytela

Department of Organic Chemistry, University of Pardubice, 532 10 Pardubice, Czech Republic


The dissociation constants of eleven amides have been measured in methanol and its mixtures with dimethyl sulfoxide (10 to 80% v/v) using sodium methoxide as the base. The experimental dissociation constants have been used to construct the H- acidity function as a function of methoxide concentration and composition of the DMSO-MeOH mixture as well as function of methoxide concentration in methanol. Moreover, with the help of construction of acidity function, the functions have been devised for constant sodium methoxide concentrations (0.025, 0.1, and 0.2 mol l-1) and changing composition of the DMSO-MeOH mixture.

Keywords: Acidity functions; Dissociation constants of amides.