General procedure for the synthesis of cyclopropanecarboxylic acid hydrazide from methyl cyclopropanecarboxylate: Methyl cyclopropanecarboxylate (10 g, 0.1 mol) was mixed with hydrazine hydrate (7.3 mL, 0.15 mol), and the reaction was carried out at reflux for 28 h and then cooled to room temperature. The reaction mixture was concentrated by evaporation under reduced pressure, followed by azeotropic distillation through toluene to remove residual water. The crude product obtained was dissolved in dichloromethane and washed with saturated sodium chloride solution. The organic phase was dried over anhydrous magnesium sulfate and evaporated under reduced pressure to remove the solvent to give cyclopropylcarbohydrazide (4.36 g, 44% yield).
