4-Aminomethyl-1-methylpyrazole

Synthesis

43193-15-3

400877-05-6

The general procedure for the synthesis of 4-(aminomethyl)-1-methylpyrazole from the compound (CAS:43193-15-3) was as follows: the oxime 1a-k (23 mmol) was dissolved in isopropanol (100 mL), and the solution was transferred to an autoclave equipped with fluoroplastic liners. Subsequently, concentrated hydrochloric acid (10.5 mL) was added and a piece of regenerated catalyst was introduced. The hydrogenation reaction was carried out at 20 °C and 10 atm hydrogen pressure for 3-5 h, during which the reaction conditions were kept constant. The reaction process was monitored by thin layer chromatography (TLC). After complete consumption of the starting oxime, the reaction solution was poured out of the autoclave and the catalyst block was washed with methanol (3 × 30 mL), the washes were combined and mechanical impurities were removed by filtration. After evaporation of the solvent, analytically pure aromatic benzylamines 3a-k were obtained.If the hydrogenation reaction was carried out in methanol (100 mL), the solvent was removed and the residue was subsequently dried by azeotropic distillation using isopropanol (250 mL). For the hydrogenation of compound 1k, the reaction mixture is additionally reacted with activated carbon for 1 hour. The catalyst block was regenerated directly in the reactor at 400 °C in a stream of hydrogen for the subsequent hydrogenation process.

References