反应详情

Methylene chloride (10 ml) solution of ethyl 6,7,8-trifluoro-1-methylamino-1,4-dihydro-4-oxoquinoline-3-carboxylate (1.0 g) and tert-butyl 2-tert-butoxycarbonylacrylate (1.52 g) was cooled in an ice bath in nitrogen atmosphere, and titanium tetrachloride (632.4 mg) was dropwise added thereto. After 30 minutes, this was diluted with ethyl acetate (100 ml) and then with water (100 ml). The organic layer was separated out, washed with water (2×50 ml), dried over magnesium sulfate and concentrated under reduced pressure to obtain an yellow syrup product. The syrup product was subjected to column chromatography with silica gel and eluted with a mixed solvent of methylene chloride/ethyl acetate (10/1) to obtain ethyl 6,7,8-trifluoro-1-[N-methyl-N-{2,2-bis(tert-butoxycarbonyl)ethyl}amino]-1,4-dihydro-4-oxoquinoline-3-carboxylate (988 mg), as a white solid.

1. additionwas dropwise added
2. customThe organic layer was separated out
3. washwashed with water (2×50 ml)
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. customto obtain an yellow syrup product
7. washeluted with a mixed solvent of methylene chloride/ethyl acetate (10/1)