Synthesis of 155-1. Sodium acetate trihydrate (1.40 g, 10.0 mmol) was added to a mixed acetic acid/water (10 mL/2 mL) solution of ethyl ethoxymethylcyanoacetate (869 mg, 5.1 mmol) and phenylhydrazine (500 mg, 4.6 mmol). The reaction mixture was placed in a microwave reactor and stirred at 130 °C for 30 min. After completion of the reaction, the mixture was cooled to room temperature and quenched by adding ice water. The resulting precipitate was collected by filtration and washed with a solvent mixture of ether and petroleum ether (1:1, v/v) to afford ethyl 3-amino-1-phenyl-1H-pyrazole-4-carboxylate (155-1) (1.03 g, 96% yield) as a yellow solid.
