Synthesis and Synthetic Application of Chloro- and Bromofuroxans

Furoxans
are potentially useful heteroaromatic units in pharmaceuticals
and agrichemicals. However, the applications for furoxan-based compounds
have been hampered due to the underdevelopment of their synthetic
methods. Herein, we report a new synthetic approach for the synthesis
of chloro- and bromofuroxans. The starting materials were dichloro-
and dibromofuroxans, and the substituents were directly introduced
to the furoxan ring in a modular fashion. The synthesized monohalofuroxans
served as substrates for the installation of a second substituent
to prepare further functionalized furoxans.