Institution: | Service de Chimie Organique, Faculté des Sciences CP 160, Université Libre de Bruxelles Avenue F. D. Roosevelt 50, 1050 Bruxelles- Belgium Laboratoire de Chimie Physique et de Cristallographie, Université Catholique de Louvain Place Louis Pasteur, 1 1348 Louvain-la-Neuve - Belgium |
Abstract: | When quinoxaline-N-oxide 1 is reacted with KCN and benzoyl chloride in water (the Reissert reaction) or methanol, the products are 2-,5- and 6- chloroquinoxaline (the latter being the major product: 42±6 %) and small amounts of 2-cyanoquinoxaline. Using three equivalents of trimethylsilyl cyanide instead of KCN, and dichloromethane as the solvent, leads to a 72 % yield of 2-cyanoquinoxaline. The reaction of trimethylsilyl cyanide and benzoyl chloride with 2,3-diphenylquinoxaline-N-oxide 2 leads to an unexpected ring-opening product 13; its structure is based on spectroscopic data and on an X-ray crystallographic analysis. |