Formic Acid → 3-(3-Cyclopentyloxy-4-methoxy-benzyl)-2-thioxanthine

HRID 429799Notes

Reaction equation

HRID 429799 reaction equation
[CH:1]1([O:6][C:7]2[CH:8]=[C:9]([CH:21]=[CH:22][C:23]=2[O:24][CH3:25])[CH2:10][N:11]2[C:18]([NH2:19])=[C:17]([NH2:20])[C:15](=[O:16])[NH:14][C:12]2=[S:13])[CH2:5][CH2:4][CH2:3][CH2:2]1.[CH:26](O)=O>>[CH:1]1([O:6][C:7]2[CH:8]=[C:9]([CH:21]=[CH:22][C:23]=2[O:24][CH3:25])[CH2:10][N:11]2[C:18]3[N:19]=[CH:26][NH:20][C:17]=3[C:15](=[O:16])[NH:14][C:12]2=[S:13])[CH2:5][CH2:4][CH2:3][CH2:2]1

Participants

3

Reactant 2

HCID 284Formic AcidHCID 184734541-(3-Cyclopentyloxy-4-methoxy-benzyl)-5,6-diamino-2-thiouracil

Product 1

HCID 184734853-(3-Cyclopentyloxy-4-methoxy-benzyl)-2-thioxanthine

Procedure

14.62 g (40 mmoles) of 1-(3-cyclopentyloxy-4-methoxy-benzyl)-5,6-diamino-2-thiouracil were dissolved in 200 ml of formic acid. The solution was concentrated in vacuo at room temperature to remove the water. 50 ml of formic acid were added and the procedure repeated. After a total of 1 hour the formic acid solution was concentrated to 30 ml at 25° and diluted with 300 ml of water. The crystals were collected, washed, and dried: 13.48 g (86.3%) of crude 5-formamide (mp 210-30° C.), which was refluxed in 86 ml of 1N NaOH for 15 min. The turbid solution was treated twice with 0.6 g of charcoal, filtered, acidified with 5N HCl to pH 2, and neutralized to pH 6.5. The amorphous solid was collected, washed, and dried at 60° C.: 11.93 g (80.1%) of crude 2-thioxanthine, which was dissolved in 150 ml of THF, treated with charcoal (5%), filtered, concentrated to 40 ml, and diluted with 250 ml of ethanol. After concentration to 120 ml the formed solid is collected, washed, and dried: 9.21 g (61.9%) of 2-thioxanthine with mp 254-65° C.

Workup

  1. concentrationThe solution was concentrated in vacuo at room temperature
  2. customto remove the water
  3. addition50 ml of formic acid were added
  4. concentrationAfter a total of 1 hour the formic acid solution was concentrated to 30 ml at 25°
  5. additiondiluted with 300 ml of water
  6. customThe crystals were collected
  7. washwashed
  8. customdried
  9. temperature13.48 g (86.3%) of crude 5-formamide (mp 210-30° C.), which was refluxed in 86 ml of 1N NaOH for 15 min
  10. additionThe turbid solution was treated twice with 0.6 g of charcoal
  11. filtrationfiltered
  12. customThe amorphous solid was collected
  13. washwashed
  14. customdried at 60° C.
  15. dissolution11.93 g (80.1%) of crude 2-thioxanthine, which was dissolved in 150 ml of THF
  16. additiontreated with charcoal (5%)
  17. filtrationfiltered
  18. concentrationconcentrated to 40 ml
  19. additiondiluted with 250 ml of ethanol
  20. concentrationAfter concentration to 120 ml the formed solid
  21. customis collected
  22. washwashed
  23. customdried

Sources & evidence

ORD record
ord-e0d6eddef27e4d5d8912a4ab44d8490b
Source dataset
uspto-grants-2001_11
Patent number
US06319928B1

Reaction notes

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