Synthesis
The general procedure for the synthesis of 1-methylcyclopropane carbohydrazide from ethyl 1-methylcyclopropane-1-carboxylate is as follows: with reference to Example 2, 1-methyl-1-cyclopropane carbohydrazide was prepared as follows: 1-methyl-1-cyclopropane carbohydrazide ethyl ester (10 g, 7.8 mmol) was mixed with hydrazine monohydrate (5.1 g, 0.1 mol), and reacted with stirring and heating for 4 hr. at 100°C. . Subsequently, toluene (50 ml) was added to the reaction system and the mixture was refluxed for 3 h, during which the water generated was removed by azeotropic distillation. Upon completion of the reaction, the reaction was cooled to room temperature, the precipitated crystals were collected by filtration and washed with diisopropyl ether to give the final target product 1-methyl-1-cyclopropanecarbohydrazide (8.9 g) as colorless crystals. The yield was 99%, and the melting point was 85°-87°C. The product was obtained as a colorless crystal.
