Hydrochloric Acid → 1,4-Dihydroxy-9H-thioxanthen-9-one

HRID 1884877Notes

Reaction equation

HRID 1884877 reaction equation
[C:1](O)(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[SH:4].[C:11]1([CH:18]=[CH:17][C:15]([OH:16])=[CH:14][CH:13]=1)[OH:12].C(=O)(O)[O-].[Na+].Cl>S(=O)(=O)(O)O>[OH:12][C:11]1[C:18]2[C:1](=[O:9])[C:2]3[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=3)[S:4][C:17]=2[C:15]([OH:16])=[CH:14][CH:13]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 785HydroquinoneHCID 54432-Mercaptobenzoic AcidHCID 516892Sodium Bicarbonate

Product 1

HCID 235049441,4-Dihydroxy-9H-thioxanthen-9-oneYield 30%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

A suspension of thiosalicylic acid (5.0 g) and hydroquinone (5.0 g) in concentrated sulfuric acid (100 ml) is stirred at room temperature for 4 h. The red suspension is poured on ice and allowed to reach ambient temperature when it is then filtered. The solid obtained is treated with saturated sodium bicarbonate and the solution was carefully neutralized with 20% hydrochloric acid. The solid is filtered, dissolved in acetone and filtered again through a plug of silica gel. The solution is concentrated and the solid purified by column chromatography with silica gel using a mixture of hexanes: ethyl acetate (1:1) as the eluent. The fraction containing the product is concentrated under reduced pressure to provide the yellow title compound (2.36 g, 30%).

Workup

  1. additionThe red suspension is poured on ice
  2. customto reach ambient temperature
  3. filtrationis then filtered
  4. customThe solid obtained
  5. filtrationThe solid is filtered
  6. dissolutiondissolved in acetone
  7. filtrationfiltered again through a plug of silica gel
  8. concentrationThe solution is concentrated
  9. customthe solid purified by column chromatography with silica gel using
  10. additiona mixture of hexanes: ethyl acetate (1:1) as the eluent
  11. additionThe fraction containing the product
  12. concentrationis concentrated under reduced pressure

Sources & evidence

ORD record
ord-89549e297cbf4ed19f1242c16921b9ac
Source dataset
uspto-grants-2004_07
Patent number
US06767919B2

Reaction notes

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