170948-06-8Relevant academic research and scientific papers
Synthesis and cathodic cleavage of a set of substituted benzenesulfonamides including the corresponding tert-butyl sulfonylcarbamates: pKa of sulfonamides
Nyasse, Barthelemy,Grehn, Leif,Ragnarsson, Ulf,Maia, Hernani L. S.,Monteiro, Luis S.,et al.
, p. 2025 - 2032 (1995)
From a series of substituted benzenesulfonic acids, most of which have previously been employed for the protection of amino functions and including a few such known to facilitate cleavage by acid, benzylamides 1a-k have been derived and studied.Initially their electrochemical cleavage potentials were determined by cyclic voltammetry in order to further explore selective deprotection within this substance group.In parallel, the corresponding tert-butyl sulfonylcarbamates 2a-k have also been prepared and studied.Among the sulfonamides investigated S-N bond cleavage was found to take place over a wide range of potentials from -1.67 to -2.64 V (excluding the nitro derivative), the most acid-labile groups requiring more negative potentials, whereas this cleavage was facilitated by 0.19-0.39 V for the sulfonylcarbamates.Small scale electolyses of 2 at controlled potential with determination of the cleavage products formed were subsequently performed.For the N-benzylbenzenesulfonamides, 1, the pKas in DMSO and in some cases also in water have been determined and found to be in the range 14.0-16.4 and 10.07-11.53, respectively.
