Phosgene → 2,5-Dichlorobenzene-1-sulfonyl isocyanate

HRID 1701918Notes

Reaction equation

HRID 1701918 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=1[S:9]([NH2:12])(=[O:11])=[O:10].C1(N=[C:20]=[O:21])CCCCC1.N12CCN(CC1)CC2.C(Cl)(Cl)=O>ClC1C=CC=CC=1>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][C:3]=1[S:9]([N:12]=[C:20]=[O:21])(=[O:10])=[O:11]

Participants

6

Reactant 4

HCID 6371Phosgene3×HCID 9237Dabco2×HCID 18502Cyclohexyl isocyanateHCID 2380452,5-Dichlorobenzenesulfonamide

Product 1

HCID 128751872,5-Dichlorobenzene-1-sulfonyl isocyanateYield 75%

Reagents, catalysts & solvents 1

HCID 7964ChlorobenzeneSolvent

Procedure

A suspension of 452 g of 2,5-dichlorobenzene sulfonamide, 260 g of cyclohexylisocyanate and 10.0 g of "Dabco" (1,4-diazabicyclo[2,2,2]octane) in 2000 ml chlorobenzene was heated for one hour to reflux in a flask fitted with a water condenser and dry-ice condenser in series, a stirrer and a thermometer. Phosgene was then added into the vapor space of the flask at such a rate that the temperature of the reaction mass was maintained at 123°-125° C. due to refluxing phosgene. During 3 hours of operation a total of 260 g of phosgene was added. The dry-ice condenser was then removed and the reaction mass refluxed to drive off excess phosgene until the temperature reached 134° C. After cooling to room temperature and filtration, the solvent and cyclohexylisocyanate were recovered by distillation at 100 mm pressure. The resulting residue was then distilled at lower pressure. Obtained were 378 g (75% yield) of 2,5-dichlorobenzenesulfonylisocyanate (B.P. 105° C./0.35 mm).

Workup

  1. temperaturewas heated for one hour
  2. temperatureto reflux in a flask
  3. customfitted with a water condenser and dry-ice condenser in series, a stirrer
  4. temperaturewas maintained at 123°-125° C. due
  5. customThe dry-ice condenser was then removed
  6. temperaturethe reaction mass refluxed
  7. customreached 134° C
  8. filtrationfiltration
  9. distillationthe solvent and cyclohexylisocyanate were recovered by distillation at 100 mm pressure
  10. distillationThe resulting residue was then distilled at lower pressure
  11. customObtained

Sources & evidence

ORD record
ord-8f61d831770e42af888d719c68454ffc
Source dataset
uspto-grants-1983_04
Patent number
US04379769

Reaction notes

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