The chlorination of acetone: a complete kinetic analysis

Abstract

. Rate constants are reported for all of the major steps followed in the chlorination of acetone, including the chlorination of mono-and 1 , 1-dichloroacetone, the chlorination of hydroxyacetone, the chlorination and hydroxide-catalyzed rearrangement of 1,l-dihydroxyacetone, and the haloform cleavage of trichloroacetone. pK, values are reported for hydroxyacetone and monochloroacetone. Rate constants for the hydrolyses of chloroacetone and 1,l-dichloroacetone are reported; these reactions are probably not SN2 displacements but proceed by addition of hydroxide and intramolecular displacement.

The chlorination of propiophenone; determination of pKa value and of the course of the reaction

“…The data gave a better fit to an integrated rate law with two exponential terms, eq. [2]; see Fig. 2.…”

“…[2] we plot log (Absorbance -a l -a6t) or log (Absorbance -a , -a4 exp (-a5t) -a6t). The key indication that eq.…”

“…We have developed a method for determining pKa values of simple ketones by analysis of the kinetics of chlorination in alkaline solution (1,2). This method has been applied to a series of ring-substituted acetophenones (3).…”

pKa values for substituted acetophenones: values determined by study of rates of halogenation

“…strength 1.0 M (KC1) using apparatus and procedures previously described (10). Hydroxide and hypochlorite solutions were titrated against standards as before (10).…”

“…Hydroxide and hypochlorite solutions were titrated against standards as before (10). With acetophenone, p-chloro-, p-methoxy-, p-nitro-, p-trimethylarnmonio-, reactions were initiated as before (10) by injection of aqueous ketone solution. With p-fluoroand p-bromoacetophenone, reactions were initiated by injection (Hamilton syringe) of aqueous hypochlorite, titrated just before use, into ketone solutions containing known hydroxide concentrations at 1 M ionic strength (KC1).…”