2-(2',5'-Dimethoxybenzoyl)-6-methoxybenzoic acid → 1,4,5-Trimethoxyanthraquinone

HRID 25914Notes

Reaction equation

HRID 25914 reaction equation
[CH3:1][O:2][C:3]1[CH:21]=[CH:20][C:19]([O:22][CH3:23])=[CH:18][C:4]=1[C:5]([C:7]1[CH:15]=[CH:14][CH:13]=[C:12]([O:16][CH3:17])[C:8]=1[C:9](O)=[O:10])=[O:6]>S(=O)(=O)(O)O>[CH3:1][O:2][C:3]1[C:4]2[C:5](=[O:6])[C:7]3[C:8](=[C:12]([O:16][CH3:17])[CH:13]=[CH:14][CH:15]=3)[C:9](=[O:10])[C:18]=2[C:19]([O:22][CH3:23])=[CH:20][CH:21]=1

Participants

3

Reactant 1

HCID 130706492-(2',5'-Dimethoxybenzoyl)-6-methoxybenzoic acid

Product 1

HCID 126357161,4,5-Trimethoxyanthraquinone

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

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.

Workup

  1. additionAfter addition the mixture
  2. temperaturewas heated on steam bath
  3. additionpoured
  4. extractionextracted with chloroform (3 × 100 ml)
  5. extractionThe organic extract
  6. washwas washed with 2% aqueous sodium hydroxide solution (10 × 100 ml) and water (100 ml)
  7. dry with materialdried over anhydrous sodium sulfate

Sources & evidence

ORD record
ord-ccff36a1b32443578130857ec2e0f101
Source dataset
uspto-grants-1979_04
Patent number
US04147706

Reaction notes

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