Kinetic Studies on the Formation of N-Nitroso Compounds XI. Nitrosation of Dimethylamine with Nitrite Esters in Aqueous Basic Media

Article abstract of DOI:10.1007/BF00816527

A kinetic study of the mechanism of the nitrosation of dimethylamine (DMA) by propyl nitrite (PrONO) in basic media to yield N-nitrosodimethylamine (NDMA) has found the rate equation to be ν=d/dt=k₂/(1++>/K₁) where and are total concentrations.At 298.2 K and I=0.25 M, k₂=(6.59+/-0.13)*1E-2 M_-1s_-1 and K₁=(1.16+/-0.07)*1E-11 M.The observed influence of ionic strength, the kinetic results obtained in water/tetrahydrofuran mixtures and in heavy water (k_H/k_D=2.09), and the value of ΔS(excit.)(-158 JK^-1mol^-1) suggest that the nitrosating agent PrONO attacks the free amine to create a tetracentric transition state and that this is the rate controlling step of the reaction.Experiments carried out with other nitrite esters have shown there to be a correlation satisfying Taft's equation between their structure and their reactivity with DMA (ρ^*=3.89), which allows the rate constant for nitrous acid to be calculated. - Keywords: Dimethylamine; Kinetics of nitrosation; Nitrite esters; N-Nitrosodimethylamine