Hydrochloric Acid → 3-Ethyl-5-(1H-indol-3-ylmethyl)-imidazolidine-2,4-dione

HRID 401607Notes

Reaction equation

HRID 401607 reaction equation
Cl.CO[C:4](=[O:17])[C@H:5]([CH2:7][C:8]1[C:16]2[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=2)[NH:10][CH:9]=1)[NH2:6].C(N(CC)CC)C.[CH2:25]([N:27]=[C:28]=[O:29])[CH3:26].Cl>ClCCl.O1CCOCC1>[CH2:25]([N:27]1[C:4](=[O:17])[CH:5]([CH2:7][C:8]2[C:16]3[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=3)[NH:10][CH:9]=2)[NH:6][C:28]1=[O:29])[CH3:26]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 8022Ethyl isocyanateHCID 8471TriethylamineHCID 2734891Methyl tryptophanate hydrochloride

Product 1

HCID 138140423-Ethyl-5-(1H-indol-3-ylmethyl)-imidazolidine-2,4-dioneYield 93.3%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 312751,4-DioxaneSolvent

Procedure

To a solution of L-tryptophan methyl ester hydrochloride (0.510 mg, 0.002 mol.) in dichloromethane (10 mL) was added triethyl amine (0.350 mL, 0.0025 mol.) followed by ethylisocyanate (0.198 mL, 0.0025 mol.). The reaction mixture was stirred at room temperature for 24 hr, and then concentrated. The residue obtained was diluted with dioxane (10 mL) and then conc. HCl (5 mL) was added. The mixture was heated at reflux for 3-4 hr. The reaction mixture was extracted in ethyl acetate, washed with water, dried and concentrated. The residue was purified by column chromatography on silica gel using 60% ethyl acetate-hexane to give 893-04 (480 mg, 93%): mp 167-170° C. (lit. 163-164° C.), 1H NMR (400 MHz, CDCl3): 0.99 (t, J=6.8 Hz, 3H), 2.95-3.01 (dd, J=8.4 and 14.8 Hz, 1H), 3.34-3.46 (m, 3H), 4.19-4.22 (dd, J=3.6 and 8.8 Hz, 1H), 5.70 (s, 1H), 6.98 (d, J=2.0 Hz, 1H), 7.06-7.10 (dd, J=8.0 and 6.8 Hz, 1H), 7.16 (dd, J=7.2 and 6.8 Hz, 1H), 7.30 (d, J=8.4 Hz, 1H), 7.55 (d, J=8.8 Hz, 1H), 8.18 (s, 1H).

Workup

  1. concentrationconcentrated
  2. customThe residue obtained
  3. temperatureThe mixture was heated
  4. temperatureat reflux for 3-4 hr
  5. extractionThe reaction mixture was extracted in ethyl acetate
  6. washwashed with water
  7. customdried
  8. concentrationconcentrated
  9. customThe residue was purified by column chromatography on silica gel using 60% ethyl acetate-hexane

Sources & evidence

ORD record
ord-1004c4b1aa5c4e818defb22d205800fd
Source dataset
uspto-grants-2014_06
Patent number
US08741942B2

Reaction notes

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