Synthesis of Benzoxazolones from Nitroarenes or Aryl Halides
摘要:
A simple and effective method for the preparation of benzoxazolones from nitroarenes or aryl halides is described. Partial reduction of a nitro group in the presence of a chloroformate followed by a microwave-assisted rearrangement/ring closure sequence provides a convenient and practical procedure to prepare this important pharmacophore. Rearrangement precursors were also accessed from aryl halides through transition-metal-catalyzed coupling.
An efficient 1-pot procedure for the Zn-mediated redn. of nitro arenes in the presence of chloroformates leading to the corresponding N,O-bisprotected hydroxylamine is described. Reactions proceed smoothly under ambient conditions in THF-water mixts. in good to excellent yield (34-81%). Solvolysis of the bisprotected hydroxylamines with NaOMe at room temp. provides access to synthetically versatile
Synthesis of Benzoxazolones from Nitroarenes or Aryl Halides
作者:Achim Porzelle、Michael D. Woodrow、Nicholas C. O. Tomkinson
DOI:10.1021/ol902885j
日期:2010.2.19
A simple and effective method for the preparation of benzoxazolones from nitroarenes or aryl halides is described. Partial reduction of a nitro group in the presence of a chloroformate followed by a microwave-assisted rearrangement/ring closure sequence provides a convenient and practical procedure to prepare this important pharmacophore. Rearrangement precursors were also accessed from aryl halides through transition-metal-catalyzed coupling.