Carbon Dioxide → Cyclohexyl isocyanate

HRID 2082584Notes

Reaction equation

HRID 2082584 reaction equation
[C:1](=[O:3])=O.[CH:4]1([NH2:10])[CH2:9][CH2:8][CH2:7][CH2:6][CH2:5]1.C(N(CC)CC)C.P(Cl)(Cl)(Cl)=O>ClCCl>[CH:4]1([N:10]=[C:1]=[O:3])[CH2:9][CH2:8][CH2:7][CH2:6][CH2:5]1

Participants

6

Reactant 4

HCID 280Carbon Dioxide2×HCID 7965CyclohexylamineHCID 8471TriethylamineHCID 24813Phosphorus oxychloride

Product 1

HCID 18502Cyclohexyl isocyanate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-10 °C

Procedure

Carbon dioxide was added subsurface to a dichloromethane (20 mL) solution containing cyclohexylamine (0.02 mol, 1.98 g), triethylamine (0.06 mol, 6.0 g) at -10° C. (ice and salt bath) for 30 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 (0.02 mol, 3.2 g) in 20 mL dichloromethane. After stirring ca. 30 min at -10° C. a white ppt formed. The ppt was filtered off and the filtrate concentrated in vacuo. The residue was extracted with 3×20 mL diethyl ether. The ether layers (light yellow) were 20 concentrated and the residue was distilled under vacuum collecting product, cyclohexyl isocyanate, at 31°-33° C. (1.45 g, 58%) of 97% purity as judged by GC. IR (neat) 2261 cm-1. 1H NMR (CDCl3) δ 3.44-3.39 (m, 1H), 1.90-1.85 (m, 2H), 1.72-1.68 (m, 2H), 1.50-1.41 (m, 2H), 1.33-1.20 (m, 3H) ppm.

Workup

  1. customformed
  2. filtrationThe ppt was filtered off
  3. concentrationthe filtrate concentrated in vacuo
  4. extractionThe residue was extracted with 3×20 mL diethyl ether
  5. concentrationconcentrated
  6. distillationthe residue was distilled under vacuum
  7. customcollecting product, cyclohexyl isocyanate
  8. customat 31°-33° C.

Sources & evidence

ORD record
ord-ca29487fcba0488ead280a9ea39beb5f
Source dataset
uspto-grants-1993_02
Patent number
US05189205

Reaction notes

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