Abstract:

Association of biological activity with heterocyclic motifs is well known and is an important strategy in drug discovery programs. Thus, the development of the fast strategies to formation of these compounds is very important. Polarized ketene dithioketals 1 have been recognized as useful building blocks in many synthetic operations. They can further be converted into the corresponding S,N- and N,N-ketals, 2 and 3 respectively, making them important as precursors for a large variety of functionalized ketals. As part of our studies on ketene dithioacetal for the synthesis of heterocyclics, we found that microwave irradiation accelerates the vinylic substitution of the anilines and amines in nitroketene S,S-acetals. In this work, we report the annulation reaction of hydroxylamines and diamines to the formation of the heterocyclic compounds.