31037-02-2

94-05-3

60-34-4

31037-02-2

Example A Synthesis of ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate: methylhydrazine (8.6 mL, 162 mmol) was slowly added to a solution of ethyl (ethoxymethylene)cyanoacetate (24.9 g, 147 mmol) in ethanol (250 mL). The reaction mixture was heated to reflux and stirred continuously for 3 days. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The resulting residue was purified by recrystallization from a mixed ethyl acetate/petroleum ether solvent to afford a white solid product identified as ethyl 5-amino-1-methyl-1H-pyrazole-4-carboxylate (21.1 g, 85% yield).