EFFICIENT SYNTHESIS OF TRI- AND DIFLUOROACETYL HYDRAZIDES AS USEFUL BUILDING BLOCKS FOR NON-SYMMETRICALLY SUBSTITUTED, FLUOROALKYLATED 1,3,4-OXADIAZOLES

Authors

  • Grzegorz Mlostoń University of Lodz, Department of Organic and Applied Chemistry, Tamka 12 Street, 91-403 Lodz, Poland
  • Emilia A. Obijalska University of Lodz, Department of Organic and Applied Chemistry, Tamka 12 Street, 91-403 Lodz, Poland
  • Alicja Żurawik University of Lodz, Department of Organic and Applied Chemistry, Tamka 12 Street, 91-403 Lodz, Poland
  • Heinz Heimgartner Department of Chemistry, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland

DOI:

https://doi.org/10.1007/3006

Keywords:

fluoroalkylated heterocycles, hydrazides, 1, 3, 4-oxadiazoles, protected hydrazines, 2, 4-triazole-3-thiones, heterocyclization

Abstract

A convenient and efficient approach to 2-arylamino-5-fluoroalkyl-1,3,4-oxadiazoles has been established via heterocyclization of tri- and difluoroacetylated thiosemicarbazides using dicyclohexylcarbodiimide. A heterocyclization performed with selected thiosemicarbazides under basic conditions led to 4-aryl-5-fluoroalkyl-2,4-dihydro-3H-1,2,4-triazole-3-thiones in moderate yields. The starting fluoroacetylated thiosemicarbazides were prepared by fluoroacetylation of benzyloxycarbonyl-protected hydrazine with a corresponding anhydride, followed by hydrogenolytic deprotection and reaction with arylisothiocyanates. Fluoroacetylated semicarbazides were prepared similarly, but all attempts to achieve their heterocyclization were unsuccessful.

How to Cite
Mlostoń, G.; Obijalska, E.; Żurawik, A.; Heimgartner, H. Chem. Heterocycl. Compd. 2016, 52, 133. [Khim. Geterotsikl. Soedin. 2016, 52, 133.]

For this article in the English edition see DOI 10.1007/s10593-016-1845-3

Published

2016-03-14

Issue

Section

Original Papers