46919-54-4Relevant academic research and scientific papers
Steric effect in alkylation reactions by N-alkyl-N-nitrosoureas: A kinetic approach
Manso,Perez-Prior,Garcia-Santos,Calle,Casado
, p. 932 - 938 (2008)
The alkylation reactions of 4-(p-nitrobenzyl)pyridine (NBP), a trap for alkylating agents with nucleophilic characteristics similar to DNA base by five N-alkyl-N-nitrosoureas (methyl-, ethyl-, propyl-, butyl-, and allylnitrosourea) were investigated in 7.3 (v/v) water/dioxane medium in the 5.0-6.5 pH range. Decomposition of alkylnitrosoureas (ANU) gives rise to alkyldiazonium ions that yield NBP-R adducts directly or through carbocations in certain instances. The NBP alkylation rate constants by these species were determined. The following sequence of alkylating potential was found: methyl- > ethyl- > allyl- > propyl- > butyl group. Application of Ingold-Taft correlation analysis to the kinetic results revealed that the NBP alkylation reactions occur mainly through steric control. The values of the molar absorption coefficients of the NBP-R adducts also reveal the determinant influence of a steric effect in the formation of alkylation adducts. The kinetic results are consistent with the biological activity of ANU. Copyright
