Nucleophilic Substitution at a Carbonyl Carbon Atom (V). Kinetic Studies on Halogen Exchange Reactions of N,N-Dialkylcarbamoyl Chlorides in Dry Acetone

[摘要] Kinetic study of halogen exchange for N,N-dimethylcarbamoyl chloride and N,N-diethylcarbamoyl chloride in acetone by using radioisotopic halide ions has been carried out at two temperatures as a part of studying the reactivity of carbonyl carbon atom. The order of nucleophilicity showed a similar tendency as that for alkyl chloroformate, but reaction rate is much slower than that for solvolysis and alkyl chloroformate. The activation parameters, ¥ÄH¡Á and ¥ÄS¡Á were found to decrease in sequence Cl- > Br- > I- for N,N-dialkylcarbamoyl chlorides. The results are interpreted in terms of solvation effect, degree of bond-breaking and bond-formation and electronic requirements.

[学科分类] 化学（综合）