Carbon Dioxide → HCID 86746571, compound

HRID 2082593Notes

Reaction equation

HRID 2082593 reaction equation
[C:1](=[O:3])=O.Cl.[CH2:5]([O:7][C:8](=[O:15])[C@H:9]([CH2:11][CH:12]([CH3:14])[CH3:13])[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:15])[C@H:9]([CH2:11][CH:12]([CH3:14])[CH3:13])[NH2:10])[CH3:6]

Participants

7

Reactant 4

HCID 280Carbon Dioxide2×HCID 8471TriethylamineHCID 24813Phosphorus oxychlorideHCID 11658447L-Leucine, ethyl ester, hydrochloride (1:1)

Product 1

HCID 86746571HCID 86746571, compound

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent2×

Procedure

Carbon dioxide was added subsurface to a dichloromethane (40 mL) solution containing leucine ethyl ester hydrochloride salt (0.025 mol, 4.89 g), N-cyclohexyl-N',N',N",N"-tetraethylguanidine (0.025 mol, 6.3 g) and triethylamine (0.10 mol, 10.0 g) at -10° C. (ice and salt bath) for 40 min at a pressure of 0 psig. The reaction mixture was transferred via cannula all at once under carbon dioxide to the precooled solution of phosphorus oxychloride (0.025 mol, 3.9 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 collecting product, leucine ethyl ester isocyanate, at 53°-58° C. (3.74 g, 81%) of 98.4 % purity as judged by GC. IR (neat) 2261, 1742 cm-1. 1H NMR (CDCl3) δ 4.23 (q, 2H, J=14.2), 3.98 (dd, 1H, Jgem =8.8, Jvic =5.5), 1.84-1.77 (m, 1H), 1.65-1.59 (m, 2H), 1.29 (t, 3H, J=7.2), 0.92 (t, 6H, J=6.7) 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
  8. customcollecting product, leucine ethyl ester isocyanate
  9. customat 53°-58° C.

Sources & evidence

ORD record
ord-5d8b5828f7554a97b8a6b7b9b4133493
Source dataset
uspto-grants-1993_02
Patent number
US05189205

Reaction notes

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