反应详情

A solution of 3-bromofuro[3,2-b]pyridine-5-carbohydrazide (0.16 g, 0.64 mmol) and triethyl orthoacetate (0.26 mL, 1.40 mmol) in n-butanol (3 mL) was heated under reflux for 1 hr. 1,8-Diazabicyclo[5.4.0]undec-7-ene (0.096 mL, 0.64 mmol) was added to the reaction mixture, and the resulting mixture was heated under reflux overnight. After cooling, the precipitate was collected by filtration, purified by silica gel column chromatography (hexane/ethyl acetate=3/1), and recrystallized from hexane/ethyl acetate to give the title compound (41 mg, yield 23%) as colorless crystals.

1. temperatureunder reflux for 1 hr
2. temperaturethe resulting mixture was heated
3. temperatureunder reflux overnight
4. temperatureAfter cooling
5. filtrationthe precipitate was collected by filtration
6. custompurified by silica gel column chromatography (hexane/ethyl acetate=3/1)
7. customrecrystallized from hexane/ethyl acetate