Carbon Dioxide → 1,4-Diisocyanatobenzene

HRID 2253861Notes

Reaction equation

HRID 2253861 reaction equation
[CH:1]1[C:6]([NH2:7])=[CH:5][CH:4]=C(N)C=1.C([N:11]([CH2:14][CH3:15])[CH2:12]C)C.[C:16](=O)=[O:17].P(Cl)(Cl)(Cl)=[O:20]>C(Cl)Cl>[C:14]1([N:11]=[C:12]=[O:20])[CH:15]=[CH:1][C:6]([N:7]=[C:16]=[O:17])=[CH:5][CH:4]=1

Participants

6

Reactant 4

HCID 280Carbon Dioxide2×HCID 7814P-PhenylenediamineHCID 8471TriethylamineHCID 24813Phosphorus oxychloride

Product 1

HCID 610091,4-DiisocyanatobenzeneYield 62%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A 9 oz. Fisher Porter bottle was charged with p-phenylenediamine (2.16 g, 20 mmol), N-cyclohexyl-N',N',N",N"-tetraethyl guanidine (10.12 g, 40 mmol), triethylamine (8.4 mL, 60 mmol) and 100 mL CH2Cl2 and then pressurized to 80 psi with CO2. An exothermic reaction occurred upon addition of the CO2 and after stirring for 30 min. at room temperature the solution was cooled to 0° C. in an ice bath. Phosphorous oxychloride (3.7 mL, 40 mmol) was added rapidly to the cold solution causing an exothermic reaction and formation of a pale yellow precipitate. Removal of the ice bath and stirring at room temperature for an additional 30 min. followed by the addition of 150 mL of diethyl ether and filtration through celite gave a pale yellow filtrate from which 2.03 g (62%) of pure p-phenylenediisocyanate was isolated by crystallization.

Workup

  1. customAn exothermic reaction
  2. temperaturewas cooled to 0° C. in an ice bath
  3. customan exothermic reaction and formation of a pale yellow precipitate
  4. customRemoval of the ice bath
  5. stirringstirring at room temperature for an additional 30 min.
  6. additionfollowed by the addition of 150 mL of diethyl ether and filtration through celite

Sources & evidence

ORD record
ord-43395d9ce3014e13b253c6deb24a272a
Source dataset
uspto-grants-1993_08
Patent number
US05233010

Reaction notes

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