Acetic Acid → 6,7-Dihydro-6-p-methoxybenzylthio-5H-pyrrolo(1,2-a)-imidazole

HRID 1089980Notes

Reaction equation

HRID 1089980 reaction equation
C(O[C:4]1[CH2:8][CH:7]([S:9][CH2:10][C:11]2[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[CH:13][CH:12]=2)[CH2:6][N:5]=1)C.CO[CH:21](OC)[CH2:22][NH2:23].C(O)(=O)C.[OH-].[Na+]>CO.O.C(OCC)(=O)C>[CH3:18][O:17][C:14]1[CH:13]=[CH:12][C:11]([CH2:10][S:9][CH:7]2[CH2:6][N:5]3[CH:21]=[CH:22][N:23]=[C:4]3[CH2:8]2)=[CH:16][CH:15]=1

Participants

8

Reactant 4

HCID 176Acetic AcidHCID 14798Sodium HydroxideHCID 89728Aminoacetaldehyde dimethyl acetalHCID 104680652-Ethoxy-4-p-methoxybenzylthio-1-pyroline

Product 1

HCID 100839776,7-Dihydro-6-p-methoxybenzylthio-5H-pyrrolo(1,2-a)-imidazole

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Procedure

2-Ethoxy-4-p-methoxybenzylthio-1-pyroline (930mg) and aminoacetaldehyde dimethylacetal (552mg) were dissolved in 50 ml of methanol and refluxed under heating for one hour after the addition of acetic acid (315mg). Ethyl acetate and water were added thereto after cooling and the solution was made alkaline with 1N sodium hydroxide aq. solution before ,subjecting to distribution therebetween. The ethyl acetate phase was washed with water and saturated aqueous solution of NaCl, then the, phase was dried over Na2SO4 and concentrated in vacuo. The residue was dissolved in 70 ml of benzene, p-toluenesulfonic acid monohydrate (1 g) was added and refluxed under heating for three hours. The solvent was distilled off in vacuo, then water and ethyl acetate were added to the residue and the solvent was made alkaline with 5% aqueous solution of sodium bicarbonate before carrying out the distribution. After the ethyl acetate phase was washed with water and dried over Na2SO4, the phase was concentrated in vacuo. The residue was purified by column chromatography using a column packed with 25 g of silica gel [eluent: chloroform/methanol (19:1 v/v)] and the fractions containing the objective compound were combined and concentrated in vacuo so that the objective compound, as brown oil, was obtained (yield: 731mg).

Workup

  1. temperaturerefluxed
  2. temperatureunder heating for one hour
  3. temperatureafter cooling
  4. washThe ethyl acetate phase was washed with water and saturated aqueous solution of NaCl
  5. dry with materialthe, phase was dried over Na2SO4
  6. concentrationconcentrated in vacuo
  7. dissolutionThe residue was dissolved in 70 ml of benzene
  8. additionp-toluenesulfonic acid monohydrate (1 g) was added
  9. temperaturerefluxed
  10. temperatureunder heating for three hours
  11. distillationThe solvent was distilled off in vacuo
  12. additionwater and ethyl acetate were added to the residue
  13. washAfter the ethyl acetate phase was washed with water
  14. dry with materialdried over Na2SO4
  15. concentrationthe phase was concentrated in vacuo
  16. customThe residue was purified by column chromatography
  17. additionthe fractions containing the objective compound
  18. concentrationconcentrated in vacuo so that the objective compound, as brown oil
  19. customwas obtained (yield: 731mg)

Sources & evidence

ORD record
ord-485ed6a4b380470b9365c3d3a252f485
Source dataset
uspto-grants-1992_01
Patent number
US05079357

Reaction notes

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