反应详情

温度

75 °C

To a mixture of 5,7-dihydroxy-4-propyl-coumarin (2.06 g 9.36 mmol) and anhydrous AICI3 (2.53 g, 18.7 mmol) was added 1,2-dichloroethane (120 mL). The resulting suspension was heated to 75° C. with vigorous stirring. After 30 minutes of stirring, a brown slurry was obtained, then nitrobenzene was introduced into the mixture resulting in an orange colored solution. A solution of anhydrous AICI3 (2.53 g, 18.7 mmol) and acetic anhydride (0.88 mL, 9.36 mmol) in 1,2-dichloroethane (40 mL) was added dropwise over a period of 1-2 hours. After addition, the mixture was allowed to stir at 75° C. for another two hours and subsequently cooled to room temperature. The resulting mixture was poured into ice and 1 N HCl. The precipitated product was filtered and then taken into ethyl acetate and the aqueous solution was extracted throughly with ethyl acetate (3×100 mL). The combined ethyl acetate extracts were dried over Na2SO4 and the solvent was removed under reduced pressure. The resulting solid was purified by column chromatography (1:1 hexane/ethyl acetate) yielding 5,7-dihydroxy-8-acetyl-4-propyl-coumarin (0.30 g, 12%): mp. 221-224° C.; 1H NMR (DMSO-d6) δ 0.94 (t, 3H), 1.58 (sextet, 2H), 2.66 (s, 3H) 2.87 (t, 2H), 6.01 (s, 1H), 6.29 (s, 1H).

1. customa brown slurry was obtained
2. customresulting in an orange colored solution
3. additionAfter addition
4. stirringto stir at 75° C. for another two hours
5. temperaturesubsequently cooled to room temperature
6. filtrationThe precipitated product was filtered
7. extractionthe aqueous solution was extracted throughly with ethyl acetate (3×100 mL)
8. dry with materialThe combined ethyl acetate extracts were dried over Na2SO4
9. customthe solvent was removed under reduced pressure
10. customThe resulting solid was purified by column chromatography (1:1 hexane/ethyl acetate)