反应详情

To a stirred suspension of dimethyl-5,7-dichloro-4-hydroxyquinoline-2,3-dicarboxylate (3.00 g, 9.09 mM) in ethanol (42 mL) was added phenylhydrazine (6.26 mL, 63.6 mM). The resulting green solution was heated to reflux for 16 hours during which time a small amount of red precipitate formed. This suspension was cooled to room temperature with stirring and additional precipitation occurred to give a thick tan suspension. The solids were collected and washed with ethanol (the ethanol washes were saved). The collected solids were recrystallized from ethanol (1.20 L) to give the phenylhydrazine salt of the title compound (1.17 g) as a tan powder. This material was stirred and refluxed in glacial acetic acid (15 mL) for 2.5 hours and then cooled to room temperature with stirring. The resulting orange suspension was filtered to give the title compound (0.629 g, 19%) as an orange powder which was slightly impure. An analytical sample of the title compound was obtained from the above saved ethanol washes by filtration of a precipitate which formed after these washes stood for several hours. Recrystallization of this collected tan powder (0.126 g) from glacial acetic acid (2 mL) gave the pure title compound (0.083 g) as an orange powder, mp 364-367° C.; MS(CI): 374 (M+H).

1. temperatureThe resulting green solution was heated
2. temperatureto reflux for 16 hours during which time a small amount of red precipitate
3. customformed
4. customadditional precipitation
5. customto give a thick tan suspension
6. customThe solids were collected
7. washwashed with ethanol (the ethanol washes
8. customThe collected solids were recrystallized from ethanol (1.20 L)