Z-Selective synthesis of o-bromoacetophenone N-tosylhydrazones and formation of 3-methylindazoles in aqueous ethanol

A practical and effective Z-selective synthesis of o-bromoacetophenone N-tosylhydrazones is developed. Subsequent cyclization of Z-tosylhydrazones to furnish 3-methylindazoles is accomplished with the aid of copper and DMEDA in aqueous ethanol. Cyclization reactions are complete at ambient temperatu...

Full description

Saved in:
Bibliographic Details
Published in:Tetrahedron letters 2010-07, Vol.51 (28), p.3613-3615
Main Authors: Kylmälä, Tuula, Udd, Sandra, Tois, Jan, Franzén, Robert
Format: Article
Language:English
Subjects:
Copper
Cyclization
Indazole
Z-Selective
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A practical and effective Z-selective synthesis of o-bromoacetophenone N-tosylhydrazones is developed. Subsequent cyclization of Z-tosylhydrazones to furnish 3-methylindazoles is accomplished with the aid of copper and DMEDA in aqueous ethanol. Cyclization reactions are complete at ambient temperature in 10 min to afford the desired compounds in excellent yields.
ISSN:0040-4039
1873-3581
DOI:10.1016/j.tetlet.2010.05.024