反应详情

To a stirred mixture of aniline (0.50 g, 5.4 mmole) and concentrated HCl (0.46 ml) in ethanol (2.5 ml) was added ethyl 5-methyl-2,4-dioxohexanoate (1.0 g, 5.4 mmole) and paraformaldehyde (0.25 g). After heating at reflux over 3 hours hot acetone (13 ml) was added and the resulting solution was cooled to room temperature and concentrated under reduced pressure. The residue was dissolved in 1N NaOH and extracted with methylene chloride. The aqueous layer was acidified to pH 1 with 3N HCl, extracted with methylene chloride, dried over sodium sulfate, filtered and concentrated under reduced pressure. Recrystallization from 10% ether in pet. ether gives 0.42 g of the title compound as a pale yellow solid. M.P. 162°-170° C.; 1H NMR (250 MHz, CDCl3) δ 1.21 (d, J=6.8 Hz, 6H), 3.24 (heptet, J=6.8 Hz, 1H), 4.52 (s, 2H), 7.23 (m, 1H), 7.43 (t, J=8.0 Hz, 2H), 7.77 (d, J=7.8 Hz); MS m/z 246.

1. temperatureAfter heating
2. additionwas added
3. concentrationconcentrated under reduced pressure
4. dissolutionThe residue was dissolved in 1N NaOH
5. extractionextracted with methylene chloride
6. extractionextracted with methylene chloride
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customRecrystallization from 10% ether in pet. ether