反应详情

温度

130 °C

Ethyl 2,3,4,5-tetrafluorobenzoylacetate was treated with triethyl orthofomate and acetic anhydrate, then with different aminonaphthols in the presence of pyridine to generate an aminoketoacid. The solution of ethyl 2,3,4,5-tetrafluorobenzoylacetate (1.10 g, 4.18 mmol) in triethylorthoformate (1 ml, 6.06 mmol) and acetic anhydride (1.8 ml, 19 mmol) was heated and stirred at 130° C. for 4 h. During the process, the formed ethyl acetate was removed. The mixture was then distilled under vacuum to yield an orange oil, which was dissolved in 30 ml dichloromethane. 1-aminonaphthalen-2-ol hydrogen chloride (90% pure from Aldrich) (1.36 g, 6.26 mmol), premixed with 2 equivalent of pyridine, was added to the dichloromethane solution, and the mixture was stirred overnight at 22° C. After the solvent was removed under reduced pressure, the remaining residue was absorbed on silica gel and subjected to flash column chromatography (gradient ethylacetate:hexanes=8:4) that yield a bright yellow powder (1.69 g). Yield=93%. 1H NMR (CDCl3) δ 1.02 (t, J=7.2 Hz, 3H), 4.01 (q, J=7.2 Hz, 2H), 4.10 (m, 1H), 7.34 (d, J=9.0 Hz, 1H), 7.41 (m, 1H), 7.60 (m, 2H), 7.82 (8, 2H), 7.91 (d, J=8.1 Hz, 1H), 8.54 (b, 1H).

1. customDuring the process, the formed ethyl acetate was removed
2. distillationThe mixture was then distilled under vacuum
3. customto yield an orange oil, which
4. stirringthe mixture was stirred overnight at 22° C
5. customAfter the solvent was removed under reduced pressure
6. customthe remaining residue was absorbed on silica gel