反应详情

A stirred mixture of 1.7 g. of 4-hydroxy-1,2-dihydro-1-methyl-2-oxo-1,8-naphthyridine-3-carboxylic acid ethyl ester in 25 ml. of phosphorus oxychloride was heated under reflux for 2 hours. The phosphorus oxychloride was removed in a rotary evaporator and the residue was poured into 100 ml. of ice water. The precipitate which formed was collected, air dried and a small amount of the 1.9 g. was recrystallized from heptane twice to give the analytical sample of the title compound, m.p. 132°-135° C.

1. additionA stirred mixture of 1.7 g
2. temperatureunder reflux for 2 hours
3. customThe phosphorus oxychloride was removed in a rotary evaporator
4. additionthe residue was poured into 100 ml
5. customThe precipitate which formed
6. customwas collected
7. customair dried
8. customwas recrystallized from heptane twice