反应详情

温度

30 °C

Cyclobranyl ester of 2-methoxy-5-nitrobenzoic acid (25.0 g, 0.040 mole) prepared according to the procedure of Example 172 was suspended in acetic acid (1 l), and thereto 6N-HCl-dioxane (21 ml) and zinc powder (25.0 g) were added. The mixture was stirred at 30° C. for 2 hours. After the reaction, zinc powder was removed by filtration. The filtrate was concentrated under reduced pressure, and the residue was extracted with chloroform. The extracts were washed successively with water and saturated aqueous NaHCO3 solution, then dried, concentrated, and the residue was recrystallized from chloroform-ethanol (1:2, v/v), giving cyclobranyl ester of 5-amino-2-methoxybenzoic acid (13.7 g) in a 57.5% yield. m.p. 193°-195° C.

1. customwas removed by filtration
2. concentrationThe filtrate was concentrated under reduced pressure
3. extractionthe residue was extracted with chloroform
4. washThe extracts were washed successively with water and saturated aqueous NaHCO3 solution
5. customdried
6. concentrationconcentrated
7. customthe residue was recrystallized from chloroform-ethanol (1:2