反应详情

To a solution (50 ml) of 4-trifluoromethylbenzohydrazide (3.06 g) and benzaldehyde (1.52 ml) in methanol was added dropwise conc. sulfuric acid (0.5 ml), and this mixture was stirred at room temperature for 1 hr. The reaction mixture was concentrated, and the residue was washed with hexane-ethanol (1:1, volume ratio) and recrystallized from ethanol to give N′-benzylidene-4-trifluoromethylbenzohydrazide (3.23 g, yield 74%) as colorless needle crystals. melting point: 216–217° C.

1. concentrationThe reaction mixture was concentrated
2. washthe residue was washed with hexane-ethanol (1:1, volume ratio)
3. customrecrystallized from ethanol