3-Amino-4-(2-nitroaryl)-2H-isoxazolin-5-ones, readily available by the sodium ethoxide catalysed cyclisation of amidoximes derived from ethyl 2-cyano-2-(2-nitroaryl) acetates, ring- close in the presence of sodium hydride to afford high yields of isoxazolo [3, 4-c] cinnolin-1 (3H)-one 5-N-oxides; hydrazine effects the chemoselective reductive scission of the isoxazoline ring in these heterocycles allowing simple and efficient synthetic access to ...
