Hydrazine hydrate (1:1) → ethyl 2-acetamido-7-hydroxy-4-(pyridin-3-yl)-4H-chromene-3-carboxylate

反応式

C([O:4][C:5]1[CH:14]=[C:13]2[C:8]([CH:9]([C:27]3[CH:28]=[N:29][CH:30]=[CH:31][CH:32]=3)[C:10]([C:22]([O:24][CH2:25][CH3:26])=[O:23])=[C:11]([N:15](C(=O)C)[C:16](=[O:18])[CH3:17])[O:12]2)=[CH:7][CH:6]=1)(=O)C.O.NN>C(O)C.C(OCC)(=O)C>[C:16]([NH:15][C:11]1[O:12][C:13]2[C:8]([CH:9]([C:27]3[CH:28]=[N:29][CH:30]=[CH:31][CH:32]=3)[C:10]=1[C:22]([O:24][CH2:25][CH3:26])=[O:23])=[CH:7][CH:6]=[C:5]([OH:4])[CH:14]=2)(=[O:18])[CH3:17]

参加物

実験手順

Ethyl 7-(acetyloxy)-2-(diacetylamino)-4-pyridin-3-yl-4H-chromene-3-carboxylate (6.989 g, 15.9 mmol) was dissolved in absolute ethanol (50 mL). Hydrazine hydrate (950 μL, 19.5 mmol) was added and the mixture stirred at room temperature for 6 h. The reaction mixture was evaporated to dryness to give an orange solid. The residue was dissolved in a mixture of ethyl acetate (200 mL) and ethanol (50 mL). Silica gel 60 (35 g) was added and the mixture evaporated to dryness. Purified by flash chromatography over silica gel 60, 40-63 μm (eluent: 75% ethyl acetate/petroleum spirits (54×100 mL fractions), packing height: 15 cm, column diameter: 5 cm). The fractions containing the major band (Rf 0.26, eluent: 75% ethyl acetate/petroleum spirits, fractions 15-53) were combined and evaporated to dryness to give the title compound (3.307 g, 59% yield) as a pale yellow powder.