反応 #54192

反応方程式

2-(2',5'-Dimethoxybenzoyl)-6-methoxybenzoic acid

→

1,4,5-trimethoxyanthraquinone

1,4,5-Trimethoxyanthraquinone

溶媒

sulfuric acid

反応条件

後処理

1. 1
   workup.ADDITIONAfter addition the mixture
2. 2
   温度was heated on steam bath
3. 3
   workup.ADDITIONpoured
4. 4
   抽出extracted with chloroform (3 × 100 ml)
5. 5
   抽出The organic extract
6. 6
   洗浄was washed with 2% aqueous sodium hydroxide solution (10 × 100 ml) and water (100 ml)
7. 7
   乾燥dried over anhydrous sodium sulfate

実験手順

2-(2',5'-Dimethoxybenzoyl)-6-methoxybenzoic acid (I) (3 g, 0.01 mole) was added in portions to stirred concentrated sulfuric acid (20 ml). After addition the mixture was heated on steam bath with constant stirring for 20 minutes, cooled to room temperature and poured onto crushed ice (400 g) and extracted with chloroform (3 × 100 ml). The organic extract was washed with 2% aqueous sodium hydroxide solution (10 × 100 ml) and water (100 ml), then dried over anhydrous sodium sulfate and the solvent stripped off under reduced pressure to yield 1,4,5-trimethoxyanthraquinone (II), as a brownish yellow solid (2.7 g, 90% yield). Recrystallization from ethanol gave yellow crystals, m.p. 201°-203° C.; IR (CDCl3), 5.92μ; NMR (CDCl3) δ, 7.88-7.20 (m, 5H), 3.94 (s, 3H), 3.92 (d, 6H). Calcd: C, 68.46; H, 4-70. Found: C, 68.33; H, 4.82.

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