Aniline → Methyl phenylcarbamate

HRID 2166653Notes

Reaction equation

HRID 2166653 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:8](=[O:12])([O:10][CH3:11])N>[Cl-].[Zn+2].[Cl-].CO>[CH3:11][O:10][C:8](=[O:12])[NH:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 6115AnilineHCID 11722Methyl Carbamate

Product 1

HCID 17451Methyl phenylcarbamateYield 82.3%

Reagents, catalysts & solvents 2

HCID 3007855ZincchlorideCatalystHCID 887MethanolSolvent

Conditions

Temperature
190 °C

Procedure

838 g aniline, 676 g methyl carbamate, 1442 g methanol and 30.0 g anhydrous pulverized zinc chloride were introduced into the pressure vessel. The pressure vessel and the column were then purged with nitrogen. The mixture was subsequently heated (with stirring) to 190° C., and the top valve of the column was adjusted so that the pressure in the apparatus was just sufficient for the reactants to reach the reaction temperature. Ammonia which evolved was separated from the evaporating alcohol in the column and then removed from the top of the column. The reaction mixture was stirred for 6.5 hours at 190° C., while the ammonia which evolved was removed. The mixture was then cooled and removed from the pressure vessel after the pressure in the apparatus had been reduced. The mixture was filtered and then distilled at atmospheric pressure to remove the excess methanol. The product was then fractionally distilled at 0.2 m bar. 1120 g N-phenyl-carbamic acid methyl ester (82.3% of the theoretical yield) were collected and crystallized. The product had a melting point of 45° to 46° C.

Workup

  1. additionwere introduced into the pressure vessel
  2. customThe pressure vessel and the column were then purged with nitrogen
  3. temperatureThe mixture was subsequently heated
  4. customAmmonia which evolved was separated from the evaporating alcohol in the column
  5. customremoved from the top of the column
  6. stirringThe reaction mixture was stirred for 6.5 hours at 190° C., while the ammonia which
  7. customevolved was removed
  8. temperatureThe mixture was then cooled
  9. customremoved from the pressure vessel after the pressure in the apparatus
  10. filtrationThe mixture was filtered
  11. distillationdistilled at atmospheric pressure
  12. customto remove the excess methanol
  13. distillationThe product was then fractionally distilled at 0.2 m bar

Sources & evidence

ORD record
ord-411da0795032494a956e49d9448466ea
Source dataset
uspto-grants-1983_06
Patent number
US04388238

Reaction notes

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