反应详情

A mixture of 2-amino-5-chloro-nicotinic acid ethyl ester (1.5 g, 7.38 mMol) and formamidine acetate (3.1 g, 29.51 mMol) in 2-ethoxyethanol (50 mL) was heated at reflux overnight. The solution was cooled to room temperature, and allowed to stand for 2 hours. The resulting precipitate was collected by filtration, rinsed with a small amount of 2-ethoxyethanol followed by diethyl ether (10 mL), and allowed to air dry. The filtrate was concentrated in-vacuo, and the residue was triturated with methylene chloride. The resulting solids were combined with the solids from the earlier filtration, and this material was crystallized from methanol to yield 475 mg of tan needles as product, in three crops. MS (ES+)=182 (M+H)+. Yield=37%.

1. temperaturewas heated
2. temperatureat reflux overnight
3. filtrationThe resulting precipitate was collected by filtration
4. washrinsed with a small amount of 2-ethoxyethanol
5. customto air dry
6. concentrationThe filtrate was concentrated in-vacuo
7. customthe residue was triturated with methylene chloride
8. filtrationThe resulting solids were combined with the solids from the earlier filtration
9. customthis material was crystallized from methanol