Microwave-Assisted Synthesis of Propesticides 1,3,4-Thiadiazole Aminophosphonates

Abstract

A novel and easy synthetic route to diethyl (5-substituted phenyl-1,3,4-thiadiazol-2-ylamino) (substituted phenyl) methylphosphonates has been achieved by the reaction of substituted benzylidene-5-(substituted phenyl)-1,3,4-thiadiazol-2-amines and diethyl phosphite under microwave irradiation. These 1,3,4-thiadiazole aminophosphonates were identified by infrared, ¹H NMR, and elemental analyses. The target compounds were obtained in better yields (71–89%) and shorter time (10 min) than with conventional heating.

Keywords:

• Microwave irradiation
• synthesis
• 1,3,4-thiadiazole aminophosphonates

ACKNOWLEDGMENTS

This work was supported by the Jiangsu High-Tech Research Project (Agriculture) (BG2007329) from the Science and Technology Department of Jiangsu Province and the Youth Teacher Academic Foundation of Nanjing University of Technology. We thank the Science and Technology Department of Jiangsu Province for financial support.

Notes

MW, microwave irradiation; Δ, conventional heating.

^a The reaction was conducted with 3a (10 mmol) and diethyl phosphite (50 mmol) at 80 °C.

All the products were investigated thoroughly by ¹H NMR, IR, and elemental analysis.

^b Isolated yields.