Abstract

One pot alkoxylation at position 7 of 6-arylpyrazino[2,3c][1,2,6]thiadiazine 2,2-dioxides with NBS or NCS in the appropriate alcohol is described. Rationalization of the mechanism of the reaction, which does not proceed through the intermediate 7-halo derivatives, is discussed on the basis of experimental reactivity and ab initio calculations. (C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.