One-Pot Synthesis of Phenylallyl Substituted Unsymmetrical Ureas Under Microwave Irradiation

Abstract

A series of phenylallyl-substituted unsymmetrical ureas were synthesized in a one-pot procedure by reactions of cinnamoyl isocyanate, which was prepared from cinnamoyl azide by Curtius rearrangement, with various aromatic amines, 2-amino-5-aryl-1,3,4-thiadiazoles and 2-amino-5-aryloxymethylene-1,3,4-thiadiazoles under microwave irradiation. Compared to conventional methods, this synthesis has the advantages of mild reaction conditions, easy handling, and high yields. The products have been characterized by analytical and spectral (IR and ¹H NMR) data.

Keywords:

• 1,3,4-thiadiazoles
• isocyanate
• microwave irradiation (MWI)
• one-pot synthesis
• unsymmetrical urea

Acknowledgments

Financial support of this work by the Foundation (No. 06-40611) of Lanzhou Jiaotong University is acknowledged.

Notes

^a Irradiated by microwave at less than 490 W;

^b Heated at 120°C.