Methanol → 5-Benzyl-2-thioxo-4-imidazolidone

HRID 2075301Notes

Reaction equation

HRID 2075301 reaction equation
[CH:1](=[C:8]1[NH:12][C:11](=[S:13])[NH:10][C:9]1=[O:14])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CO>C(O)(=O)C.[Zn]>[CH2:1]([CH:8]1[NH:12][C:11](=[S:13])[NH:10][C:9]1=[O:14])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 887MethanolHCID 28316104-Benzylidene-2-sulfanyl-4H-imidazol-5-ol

Product 1

HCID 30345745-Benzyl-2-thioxo-4-imidazolidone

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 176Acetic AcidSolvent

Procedure

5-Benzylidene-2-thiohydantoin (24.5 g, 0.12 mol) was dissolved in 150 mL of acetic acid in a flask equipped with a thermometer, a mechanical stirrer, a reflux condenser, and argon pressure. Zinc dust (11.8 g, 0.18 mol) was added, and the flask was immersed in a 130° bath. After 2.5 hr at reflux, HPLC analysis showed no starting material. The mixture was allowed to cool to 50°, and a 500 mL portion of methanol was added. The mixture was returned to reflux, for about 5 min and was then allowed to cool to 63°. The hot mixture was filtered through Whatman #4 paper. The filtrate was concentrated to a paste in vacuo. The residue was mixed with 400 mL of a 3:7 mixture of isopropanol:dichloromethane. The solution was filtered and washed with 1×200 mL and 1×100 mL of water and 1×100 mL of saturated aqueous sodium chloride. After the solution had been filtered through 1 PS paper, it was concentrated at aspirator pressure and high vacuum to yield 17.5 g (71%). HPLC analysis indicated a purity of 78% at 210 nm. NMR (d6-DMSO) δ 12.1 (bs, 1H), 10.7 (bs, 1H), 7.8 (s, 5H), 5.2 (t, 1H), 3.6 (d, 2H).

Workup

  1. customequipped with a thermometer, a mechanical stirrer, a reflux condenser, and argon pressure
  2. customwas immersed in a 130°
  3. temperatureAfter 2.5 hr at reflux
  4. temperatureto cool to 50°
  5. temperatureto reflux, for about 5 min
  6. temperatureto cool to 63°
  7. filtrationThe hot mixture was filtered through Whatman #4 paper
  8. concentrationThe filtrate was concentrated to a paste in vacuo
  9. additionThe residue was mixed with 400 mL of a 3:7 mixture of isopropanol
  10. filtrationThe solution was filtered
  11. washwashed with 1×200 mL and 1×100 mL of water and 1×100 mL of saturated aqueous sodium chloride
  12. filtrationAfter the solution had been filtered through 1 PS paper, it
  13. concentrationwas concentrated at aspirator pressure and high vacuum
  14. customto yield 17.5 g (71%)

Sources & evidence

ORD record
ord-5210986599fb428fbbc7293dbe466a7b
Source dataset
uspto-grants-2011_04
Patent number
US07919630B2

Reaction notes

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