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

HRID 4153

Reaction equation

HRID 4153 reaction equation
[NH2:1][S:2]([C:5]1[CH:14]=[C:13]([O:15][CH2:16][CH3:17])[CH:12]=[CH:11][C:6]=1[C:7]([O:9][CH3:10])=[O:8])(=[O:4])=[O:3].C(N=[C:23]=[O:24])CCC.C(Cl)(Cl)=O>>[CH2:16]([O:15][C:13]1[CH:12]=[CH:11][C:6]([C:7]([O:9][CH3:10])=[O:8])=[C:5]([S:2]([N:1]=[C:23]=[O:24])(=[O:3])=[O:4])[CH:14]=1)[CH3:17]

Participants

4

Reactant 3

HCID 6371PhosgeneHCID 8110Butyl isocyanateHCID 13987872Methyl 2-(aminosulfonyl)-4-ethoxybenzoate

Product 1

HCID 13987873Methyl 4-ethoxy-2-(isocyanatosulfonyl)benzoateYield 98.4%

Procedure

A solution of methyl 2-(aminosulfonyl)-4-ethoxybenzoate (7.56 g, 29.2 mmol), n-butyl isocyanate (3.29 mL, 29.2 mmol), and 1,4-diaza[2.2.2]bicyclooctane (0.13 g, 1.2 mmol) in mixed xylenes 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 4-ethoxy-2-(isocyanatosulfonyl)benzoate as a cloudy yellow oil (8.2 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-afb1397756f348c8aace29697e67d299
Source dataset
uspto-grants-1988_02
Patent number
US04724039

Linked notes

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