Synthesis of novel 2,5-disubstituted-1,3,4-selenadiazoles from fatty acid hydrazides

A series of novel unsaturated hydroxy and non-hydroxy fatty acid residue substituted 1,3,4-selenadiazoles were described here. These derivatives were synthesized from the reaction of fatty acid hydrazide 1(a-d) with acetyl chloride in the presence of anhydrous sodium carbonate in tetrahydrofuran and water at 0 °C, to form N′-acetyl undec-10-enoic hydrazide 2a, N′-acetyl-(9Z)-octadec-9-enoic hydrazide 2b, N′-acetyl-(9Z, 12R)-12-hydroxy-9-enoic hydrazide 2c, and N′-acetyl-(9R, 12Z)-9-hydroxy-12-enoic hydrazide 2d. Then these hydrazines (dicarbonyl compound) on reaction with Woollin's reagent (WR) in toluene led to the corresponding 2-(dec-9′-enyl)-5-methyl-1,3,4-selenadiazole 3a, 2-[(8′Z)-heptadec-8′-enyl]-5-methyl-1,3,4-selenadiazole 3b, 2-[(8′Z, 11′R)-11′-hydroxy-octadec-8′-enyl)]-5-methyl-1,3,4-selenadiazole 3c, and 2-[(8′R, 11′Z)-8′-hydroxy-octadec-11′-enyl)]-5-methyl-1,3,4-selenadiazole 3d, respectively. These synthesized compounds were characterized on the basis of IR, 1H NMR, 13C NMR, mass spectra and elemental analysis results.