反应详情

3-[(4-Methoxybenzyl)oxy]benzoic acid (9.26 g, 35.9 mmol), acethydrazide (3.98 g, 53.8 mmol), HOBT (6.59 g, 43 mmol) and EDC (10.3 g, 53.8 mmol) were weighed into a 200 mL RB flask. DMF (60 mL) was added. The mixture was stirred vigorously at room temperature. The solid dissolved within 5 min. LC-MS showed complete consumption of the acid after 30 min. DMF was removed at 60° C. under vacuum. The residue was treated with 100 mL EtOAc/water (1/1) and was allowed to stand overnight. The solid was collected via filtration and washed with EtOAc. The crude N′-acetyl-3-[(4-methoxybenzyl)oxy]benzohydrazide (8 g) was suspended in 100 mL THF and was heated under reflux in the presence of Burgess' reagent (12.8 g, 53.8 mmol) for 1 hour. The solution was cooled and directly passed through a plug of silica gel (300 gram) which was washed thoroughly with 20% acetone/hexanes. The eluent was concentrated to give the crude product as white solid.

1. dissolutionThe solid dissolved within 5 min
2. customconsumption of the acid after 30 min
3. customDMF was removed at 60° C. under vacuum
4. additionThe residue was treated with 100 mL EtOAc/water (1/1)
5. filtrationThe solid was collected via filtration
6. washwashed with EtOAc
7. temperaturewas heated
8. temperatureThe solution was cooled
9. washwas washed thoroughly with 20% acetone/hexanes
10. concentrationThe eluent was concentrated