Iodine → Tibenelast

HRID 1583577Notes

Reaction equation

HRID 1583577 reaction equation
[CH2:1]([O:3][C:4]1[CH:5]=[C:6]([CH:13]=[C:14]([SH:18])[C:15]([OH:17])=[O:16])[CH:7]=[CH:8][C:9]=1[O:10][CH2:11][CH3:12])[CH3:2].O1CCOCC1.II.S(=O)(O)[O-].[Na+]>O>[CH2:1]([O:3][C:4]1[C:9]([O:10][CH2:11][CH3:12])=[CH:8][C:7]2[S:18][C:14]([C:15]([OH:17])=[O:16])=[CH:13][C:6]=2[CH:5]=1)[CH3:2]

Participants

6

Reactant 4

HCID 807IodineHCID 312751,4-DioxaneHCID 23665763Sodium BisulfiteHCID 86131838beta-(3,4-Diethoxyphenyl)-alpha-mercaptoacrylic acid

Product 1

HCID 59913Tibenelast

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Two grams of β-(3,4-diethoxyphenyl)-α-mercaptoacrylic acid were dissolved in 68.5 ml. of dioxane. To the solution were added 2.74 g. of iodine. The solution was heated at 60°-70° C. for 22 hours. The reaction was then poured into 550 ml. of water, decolorized with 11.0 g. of sodium bisulfite, and stirred vigorously for several minutes. The crude product was collected by filtration and dissolved in approximately 15 ml. of a warm 10% sodium hydroxide solution. The alkaline solution was treated with decolorizing carbon and filtered. The solution was allowed to stand at refrigerator temperature overnight. The resulting pink crystals were collected and dissolved in water. Dilute hydrochloric acid was added and the resulting precipitate was collected to give 0.59 g. of the desired title product. Two recrystallizations from 95% ethanol gave white needles, m.p. 243°-245° C.

Workup

  1. additionTo the solution were added 2.74 g
  2. temperatureThe solution was heated at 60°-70° C. for 22 hours
  3. additionThe reaction was then poured into 550 ml
  4. filtrationThe crude product was collected by filtration
  5. dissolutiondissolved in approximately 15 ml
  6. additionThe alkaline solution was treated with decolorizing carbon
  7. filtrationfiltered
  8. customto stand at refrigerator temperature overnight
  9. customThe resulting pink crystals were collected
  10. dissolutiondissolved in water
  11. additionDilute hydrochloric acid was added
  12. customthe resulting precipitate was collected
  13. customto give 0.59 g

Sources & evidence

ORD record
ord-611371123f5549adacb86da7175e7a5a
Source dataset
uspto-grants-1985_11
Patent number
US04552891

Reaction notes

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