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ChemicalBook CAS DataBase List 3',4',5,7-TETRAMETHOXYFLAVONE
855-97-0

3',4',5,7-TETRAMETHOXYFLAVONE synthesis

3synthesis methods
1,3-Propanedione, 1-(3,4-dimethoxyphenyl)-3-(2-hydroxy-4,6-dimethoxyphenyl)-

71847-57-9

3',4',5,7-TETRAMETHOXYFLAVONE

855-97-0

Example 17: Synthesis of 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-4H-chromen-4-one (14) 1. 1-(3,4-dimethoxyphenyl)-3-(2-hydroxy-4,6-dimethoxyphenyl)propane-1,3-dione (7.40 g, 20.53 mmol, 1 eq.) was suspended in glacial acetic acid (30 mL) and heated to 100°C. 2. 20 mL of an acetic acid solution of 20% H2SO4 was added to the suspension and kept stirring at 100 °C for 10 min. 3. The reaction mixture was poured into 150 g of crushed ice and a light yellow gel-like solid precipitated. 4. The solid was collected, partially dried by filtration and dispensed between 300 mL of CHCl3 and 300 mL of distilled water. 5. The organic layer was separated and washed sequentially with 150 mL of 5% NaHCO3 solution and 150 mL of saturated brine. 6. The organic layer was dried over MgSO4, filtered and the solvent evaporated to give a light yellow solid. 7. 6.05 g (86% yield) of white needle-like crystals were obtained by recrystallization from 50 mL of acetone. Product Characterization: - Molecular weight: 342.34 (C19H18O6) - 1H-NMR (CDCl3, 300 MHz) δ (ppm, J/Hz): 3.86 (s, 3H, MeO), 3.90 (s, 6H, MeOx2), 3.92 (s, 3H, MeO), 6.30 (d, 1H, J = 2.1, H-6), 6.48 (d, 1H, J = 2.1, H-8), 6.53 (s 1H, H-3), 6.88 (d, 1H, J = 8.6, H-5'), 7.24 (d, 1H, J = 2.1, H-2'), 7.42 (dd, 1H, J = 2.1, 8.6, H-6') - 13C-NMR (CDCl3, 75 MHz) δ (ppm): 55.8 (MeO), 56.1 (MeOx2), 56.4 (MeO), 92.9 (C-6), 96.1 (C-8), 107.8 (C-3), 108.5 (C-2'), 109.1 (C-4a), 111.0 (C-5'), 119.5 (C-6') 119.5 (c-6'), 123.9 (c-1'), 149.2 (c-4'), 151.7 (c-3'), 159.8 (c-8a), 160.6 (c-5), 160.8 (c-2), 163.9 (c-7), 177.6 (c-4)

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