Carbon Dioxide → HCID 86746570, compound

HRID 2082592Notes

Reaction equation

HRID 2082592 reaction equation
[C:1](=[O:3])=O.Cl.[CH2:5]([O:7][C:8](=[O:18])[C@H:9]([CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[NH2:10])[CH3:6].C(N(CC)CC)C.P(Cl)(Cl)(Cl)=O>ClCCl.C(OCC)C>[N-:10]=[C:1]=[O:3].[CH2:5]([O:7][C:8](=[O:18])[C@H:9]([CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[NH2:10])[CH3:6]

Participants

7

Reactant 4

HCID 280Carbon DioxideHCID 8471TriethylamineHCID 24813Phosphorus oxychlorideHCID 165085Ethyl L-phenylalaninate hydrochloride

Product 1

HCID 86746570HCID 86746570, compound

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent2×

Procedure

Carbon dioxide was added subsurface to a dichloromethane (40 mL) solution containing phenylalanine ethyl ester hydrochloride salt (0.02 mol, 4.6 g), N-cyclohexyl-N',N',N",N"-tetraethylguanidine (0.02 mol, 5.1 g) and triethylamine (0.06 mol, 6.0 g) at -10° C. (ice and salt bath) for 40 min at a pressure of 0 psig. The reaction mixture was transferred rapidly via cannula under carbon dioxide to the precooled solution of phosphorus oxychloride (0.02 mol, 3.1 g) in 40 mL dichloromethane. After stirring for 20 min at -10° C. diethylether (50 mL) was added to the reaction mixture. A white ppt formed and was filtered off. The filtrate was concentrated in vacuo and the residue was extracted with 3×25 mL diethylether. The ether layers were concentrated and the residue was distilled under vacuum (ca. 0.1-0.3 torr) collecting product, phenylalanine ethyl ester isocyanate, at 96°-106° C. (2.85 g, 64.5 %) of 99% purity as judged by GC. IR (neat) 2261, 1742 cm-1. 1H NMR (CDCl3) δ 7.34-7.18 (m, 5H), 4.24 (q, 2H, J=14.1), 4.23 (d, 1H, J=7.8), 3.141 (dd, 1H, Jgem =13.7, Jvic =4.8), 3.02 (dd, 1H, Jgem =13.8, Jvic =7.7), 1.28 (t, 3H, J=7.1) ppm.

Workup

  1. additionwas added to the reaction mixture
  2. customA white ppt formed
  3. filtrationwas filtered off
  4. concentrationThe filtrate was concentrated in vacuo
  5. extractionthe residue was extracted with 3×25 mL diethylether
  6. concentrationThe ether layers were concentrated
  7. distillationthe residue was distilled under vacuum (ca. 0.1-0.3 torr)
  8. customcollecting product, phenylalanine ethyl ester isocyanate
  9. customat 96°-106° C.

Sources & evidence

ORD record
ord-e1106f11cbce4eef82109b166ae5f5ba
Source dataset
uspto-grants-1993_02
Patent number
US05189205

Reaction notes

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