2031
Electrochemical Behavior of 2-Halo-N-Phenylacetamides at a Carbon Cathode

Monday, 14 May 2018: 14:20
Room 616 (Washington State Convention Center)
A. G. Couto Petro and D. G. Peters (Indiana University)
Haloacetamides and haloacetanilides have been utilized for the synthesis of many compounds such as, but not limited to, β-lactams,1 N,N-bis-(phenylcarbamoylmethyl) dimethylammonium,2 and oxazolidine-2,4-diones.3 Therefore, it is important to understand fully how these haloacetamides behave as well as the reaction pathways they undergo. Electrochemical studies of 2-chloro-N-phenylacetamide have been reported at carbon cathodes, and were successful in demonstrating the reductive cleavage of the carbon–halogen bond. A mechanism for the aforementioned reduction has been proposed.4 This project’s primary objective is to compare the electrochemical behavior of a series of 2-halo-N-phenylacetamides and to elucidate a more complete mechanistic picture for the reduction of this class of compounds.

In the present investigation, we have conducted cyclic voltammetry and controlled-potential electrolysis studies of 2-iodo-N-phenylacetamide and 2-bromo-N-phenylacetamide at a carbon cathode to understand further the electrochemical behavior of 2-halo-N-phenylacetamides. Reduction of 2-bromo-N-phenylacetamide and 2-iodo-N-phenylacetamide in dimethylformamide (DMF) containing 0.05 M tetramethylammonium tetrafluoroborate (TMABF4) results in cyclic voltammetry peaks at –0.9 and –1.4 V (bromo) and –0.6 and –1.1 V (iodo) vs. a Cd(Hg) reference electrode. Analysis of the products resulting from controlled-potential electrolyses of both analytes by means of gas chromatography–mass spectrometry (GC–MS) indicates the presence of dehalogenated species as the primary products.

  1. Casadei, M. A.; Di Rienzo, B.; Inesi, A.; Moracci, F. M., Electrochemical studies on haloamides. Part 3. Haloacetamides and halo-acetohydroxamates. J. Chem. Soc., Perkin Trans. 1 1992, 375–378.
  2. Walker, M. J., Treating cough and tussive attacks. Google Patents: 2012.
  3. Casadei, M. A.; Cesa, S.; Inesi, A., Electrochemical studies on haloamides. Part XII. Electrosynthesis of oxazolidine-2,4-diones. Tetrahedron 1995, 51, 5891–5900.
  4. Pasciak, E. M.; Sengupta, A.; Mubarak, M. S.; Raghavachari, K.; Peters, D. G., Electrochemical reduction of 2-chloro-N-phenylacetamides at carbon and silver cathodes in dimethylformamide. Electrochim. Acta 2014, 127, 159–166.