反应详情

To a mixture of methyl 5-methyl-2-valerylaminobenzoate (12.8 g) in acetic anhydride (5.9 g) was added dropwise, while stirring under ice-cooling, fuming nitric acid (6.7 ml), followed by stirring for 3 hours. To the reaction mixture was added ice water, which was extracted with ethyl acetate. The extract was washed with an aqueous solution of sodium bicarbonate and water, which was then dried. The solvent was evaporated to dryness, and the residue was purified by column chromatography on silica gel. Crystals thus obtained were recrystallized from isopropyl ether gave colorless crystals (8.5 g, 60%), m.p. 59-60° C.

1. additionwas added dropwise
2. temperaturecooling
3. stirringby stirring for 3 hours
4. extractionwas extracted with ethyl acetate
5. washThe extract was washed with an aqueous solution of sodium bicarbonate and water, which
6. customwas then dried
7. customThe solvent was evaporated to dryness
8. customthe residue was purified by column chromatography on silica gel
9. customCrystals thus obtained
10. customwere recrystallized from isopropyl ether