Carbon Dioxide → Phenyl isocyanate

HRID 2082588Notes

Reaction equation

HRID 2082588 reaction equation
[C:1](=[O:3])=O.[NH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1.C(N(CC)CC)C.P(Cl)(Cl)(Cl)=O>ClCCl>[C:5]1([N:4]=[C:1]=[O:3])[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 6115AnilineHCID 8471TriethylamineHCID 24813Phosphorus oxychloride

Product 1

HCID 7672Phenyl isocyanate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-10 °C

Procedure

Carbon dioxide was added subsurface to a dichloromethane (20 mL) solution containing aniline (Ph--NH2) (0.02 mol, 1.86 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, 3.2 g) in 20 mL dichloromethane. After stirring for 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 were concentrated and the residue was distilled under vacuum (ca. 0.1-0.3 torr) collecting product, phenyl isocyanate, at 71°-73° C. (1.45 g, 61%) of 99% purity as judged by GC. IR (neat) 2266 cm-1. 1H NMR (CDCl3) δ 7.30 (t, 2H, J=7.8), 7.17 (t, 1H, J=7.5), 7.07 (d, 2H, J=6.7) ppm.

Workup

  1. customformed
  2. filtrationwas filtered off
  3. concentrationthe filtrate concentrated in vacuo
  4. extractionThe residue was extracted with 3×20 mL diethyl ether
  5. concentrationThe ether layers were concentrated
  6. distillationthe residue was distilled under vacuum (ca. 0.1-0.3 torr)
  7. customcollecting product, phenyl isocyanate
  8. customat 71°-73° C.

Sources & evidence

ORD record
ord-a2b0fcbe9a3546a5a7dfd35be46eac46
Source dataset
uspto-grants-1993_02
Patent number
US05189205

Reaction notes

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