反应详情

4-Chlorophenoxysulphonylisocyanate (0.2 ml, 290 mg) was added to a suspension of ethyl 6,9-dihydro-4,6-dioxo-8-methoxycarbonyl-10-propyl-4H-pyrano[3,2-g] quinoline-2-carboxylate (385 mg, 1 mmol) in acetonitrile (5 ml), and then refluxed for 0.5 h. The solution was allowed to cool, ethanolic hydrogen chloride solution (2 ml) was added, and after 5 minutes the pale yellow solution was poured into aqueous ammonial solution (0.88 specific gravity, 5 ml) at 5° C., to give a thick orange precipitate. Filtration and washing with ethanol (10 ml) gave the title compound, 320 mg (83%) as an orange powder, mp 268°-270° C. (decomposes).

1. temperaturerefluxed for 0.5 h
2. temperatureto cool
3. additionafter 5 minutes the pale yellow solution was poured into aqueous ammonial solution (0.88 specific gravity, 5 ml) at 5° C.
4. customto give a thick orange precipitate
5. filtrationFiltration
6. washwashing with ethanol (10 ml)