Xanthine → 2-Thioxanthine

HRID 1600832Notes

Reaction equation

HRID 1600832 reaction equation
[NH:1]1[C:10](=[O:11])[C:9]2[NH:8][CH:7]=[N:6][C:5]=2[NH:4][C:2]1=O.P12(SP3(SP(SP(S3)(S1)=S)(=S)S2)=S)=[S:13].[OH-].[Na+]>N1C=CC=CC=1>[NH:1]1[C:10](=[O:11])[C:9]2[NH:8][CH:7]=[N:6][C:5]=2[NH:4][C:2]1=[S:13]

Participants

5

Reactant 3

HCID 1188XanthineHCID 14798Sodium HydroxideHCID 14817Phosphorus sulfide (P2S5)

Product 1

HCID 12681852-ThioxanthineYield 322.7%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

2.77 g (8.0 mM) of xanthine and 2.13 g (9.6 mM) of phosphorus pentasulfide were heated under reflux in 50 ml of pyridine for 7 days. At 0° C., 10.6 ml of 2N NaOH were added within 15 min. The solvents were evaporated in vacuo and the residue suspended (slow crystallization) in water. The solid was collected and washed, redissolved in 50 ml of 1N NaOH and 50 ml of isopropanol, treated twice with 0.3 g of charcoal, filtered neutralized with 5N HCl to pH 7. The isopropanol was distilled off with addition of water and the solid collected, washed and dried to give 2.60 g (89.7%) of crude thioxanthine, which was dissolved in 40 ml of dichloromethane and filtered through 30 g of silica gel: 1.91 g (65.9%) of 6-thioxanthine were recovered, mp 153-4° C.

Workup

  1. customThe solvents were evaporated in vacuo
  2. custom(slow crystallization) in water
  3. customThe solid was collected
  4. washwashed
  5. dissolutionredissolved in 50 ml of 1N NaOH
  6. addition50 ml of isopropanol, treated twice with 0.3 g of charcoal
  7. filtrationfiltered
  8. distillationThe isopropanol was distilled off with addition of water
  9. customthe solid collected
  10. washwashed
  11. customdried

Sources & evidence

ORD record
ord-45d32d5d03114b7cbedf2cbac99bce91
Source dataset
uspto-grants-1999_11
Patent number
US05977119

Reaction notes

Loading…