Phosgene → Methyl 2-(isocyanatosulfonyl)-4-(methylthio)benzoate

HRID 703047Notes

Reaction equation

HRID 703047 reaction equation
[NH2:1][S:2]([C:5]1[CH:14]=[C:13]([S:15][CH3:16])[CH:12]=[CH:11][C:6]=1[C:7]([O:9][CH3:10])=[O:8])(=[O:4])=[O:3].C(N=[C:22]=[O:23])CCC.C(Cl)(Cl)=O>>[N:1]([S:2]([C:5]1[CH:14]=[C:13]([S:15][CH3:16])[CH:12]=[CH:11][C:6]=1[C:7]([O:9][CH3:10])=[O:8])(=[O:4])=[O:3])=[C:22]=[O:23]

Participants

4

Reactant 3

HCID 6371PhosgeneHCID 8110Butyl isocyanateHCID 13988046Methyl 2-(aminosulfonyl)-4-(methylthio)benzoate

Product 1

HCID 14748707Methyl 2-(isocyanatosulfonyl)-4-(methylthio)benzoateYield 111.4%

Procedure

A solution of methyl 2-(aminosulfonyl)-4-(methylthio)benzoate (5.23 g, 20.0 mmol), n-butyl isocyanate (2.25 mL, 20.0 mmol). and 1,4-diaza[2.2 2]bicyclooctane (0.09 g. 0.8 mmol) in mixed Xylenes (50 mL) was heated at reflux for 10 minutes. Phosgene was then added at such a rate that the internal temperature stayed at 133° C. or above. When consumption of phosgene ceased, the solution was cooled to room temperature and then filtered under nitrogen. Rotary evaporation gave methyl 2-(isocyanatosulfonyl)-4-(methylthio)benzoate as a yellow oil (6.4 g). This was used immediately without further purification or characterization.

Workup

  1. temperatureat reflux for 10 minutes
  2. customstayed at 133° C. or above
  3. customWhen consumption of phosgene
  4. filtrationfiltered under nitrogen
  5. customRotary evaporation

Sources & evidence

ORD record
ord-65f5a55613bd4e1384ea9913338ffdd1
Source dataset
uspto-grants-1991_01
Patent number
US04981509

Reaction notes

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