Benzylamine → 3-(5-Benzylamino-3-bromo-4-nitropyrazol-1-yl)propan-1-ol

Participants

Reaction Steps

A mixture of 3-(3,5-dibromo-4-nitropyrazol-1-yl)propan-1-ol (3-2) (17.1 g, 52 mmol), EtOH (100 ml) and benzylamine (27.9 g, 260 mmol) was refluxed for 15 hours. The reaction medium was concentrated to the maximum under reduced pressure. The highly viscous residue was suspended in EtOAc (100 ml) and EtOH (100 ml). The organic phase was washed with NaCl solution (10%, 100 ml) and then dried over Na2SO4. After evaporating off the solvent under reduced pressure, an orange-colored oil was obtained (13.6 g), which was subsequently purified by column chromatography (gradient: 10%/90% EtOAc/hexane to 40%/60% EtOAc/hexane) in order to obtain, after evaporating off the solvent, the 3-(5-benzylamino-3-bromo-4-nitropyrazol-1-yl)propan-1-ol in the form of a yellow solid (8.8 g, 48%).

Provenance & Evidence