25016-11-9

66121-71-9

The general procedure for the synthesis of 1-methylpyrazole-4-carbonitrile using 1-methyl-1H-pyrazole-4-carboxaldehyde as starting material was as follows: 1-methyl-1H-pyrazole-4-carboxaldehyde (11.0 g, 0.1 mol), sodium bromate (6.0 g, 0.04 mol) and acetic acid (50 g, 0.83 mol) were mixed in a reaction flask at room temperature. Subsequently, 25% ammonia (12.5 g) and water (100 mL) were added to the mixture. The reaction mixture was heated to 90 °C and after the reaction was observed to be exothermic, the reaction temperature was maintained at 100 °C and the reflux reaction was carried out for 1 h (monitored by TLC until 1-methyl-1H-pyrazole-4-carbaldehyde was fully reacted). Upon completion of the reaction, the reaction solution was cooled to room temperature and poured into ice water for quenching and dilution. The reaction solution was adjusted to neutral with a suitable base solution and subsequently extracted with ethyl acetate and the organic phase was dried over anhydrous sodium sulfate. After concentration of the organic phase, the product was purified by distillation under reduced pressure and recrystallization. The final product was 1-methylpyrazole-4-carbonitrile (10.2 g, 95% yield), which was analyzed by HPLC with a purity of more than 99%.