Acetic Acid → 2,6-Dichloro-2',3'-dihydroxy-4'-methoxy-6'-methyl-benzophenone

HRID 965458

Reaction equation

HRID 965458 reaction equation
[Cl:1][C:2]1[CH:22]=[CH:21][CH:20]=[C:19]([Cl:23])[C:3]=1[C:4]([C:6]1[C:11]([CH3:12])=[CH:10][C:9]([O:13][CH3:14])=[C:8]([O:15]C)[C:7]=1[O:17]C)=[O:5].Br.C(O)(=O)C>O>[Cl:1][C:2]1[CH:22]=[CH:21][CH:20]=[C:19]([Cl:23])[C:3]=1[C:4]([C:6]1[C:11]([CH3:12])=[CH:10][C:9]([O:13][CH3:14])=[C:8]([OH:15])[C:7]=1[OH:17])=[O:5]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 260Hydrogen BromideHCID 227199532,6-Dichloro-2',3',4'-trimethoxy-6'-methyl-benzophenone

Product 1

HCID 545695512,6-Dichloro-2',3'-dihydroxy-4'-methoxy-6'-methyl-benzophenone

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
75 °C

Procedure

A mixture of 2,6-dichloro-2',3',4'-trimethoxy-6'-methyl-benzophenone (1.78 g; 5 mmol) hydrobromic acid (7.5 ml; 30% in acetic acid) and acetic acid (7.5 ml) is stirred at 75° C. for 2 hours. Water is added and the mixture extracted with methylenechloride. The extract is washed with water and shaken with 2N sodium hydroxide. The alcaline solution is acidified with hydrochloric acid, the separated compound dissolved in methylenechloride and the solution washed with water. After evaporation of the solvent purification is carried out by chromatography (flash column, filled with 36 g of silicagel; elution with 500 ml of petrolether/ethylacetate (4:1; v/v) and 250 ml of petrolether/ethylacetate (1:1; v/v)). the fraction containing the compound is concentrated, the compound crystallized. The yellow crystalls are washed with petrolether and sucked off; 0.64 g (39% y), mp. 182° C.

Workup

  1. extractionthe mixture extracted with methylenechloride
  2. washThe extract is washed with water
  3. stirringshaken with 2N sodium hydroxide
  4. dissolutionthe separated compound dissolved in methylenechloride
  5. washthe solution washed with water
  6. customAfter evaporation of the solvent purification
  7. additionis carried out by chromatography (flash column, filled with 36 g of silicagel; elution with 500 ml of petrolether/ethylacetate (4:1; v/v) and 250 ml of petrolether/ethylacetate (1:1; v/v))
  8. additionthe fraction containing the compound
  9. concentrationis concentrated
  10. customthe compound crystallized
  11. washThe yellow crystalls are washed with petrolether

Sources & evidence

ORD record
ord-e0902ff2670344b8a8a18cf4659cc88c
Source dataset
uspto-grants-1998_06
Patent number
US05773663

Linked notes

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