Phosgene → 1-Isocyanato-3,5-dimethoxybenzene

HRID 615883Notes

Reaction equation

HRID 615883 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:7]=[C:8]([O:10][CH3:11])[CH:9]=1)[NH2:6].[C:12](Cl)(Cl)=[O:13]>C1(C)C=CC=CC=1>[CH3:11][O:10][C:8]1[CH:7]=[C:5]([N:6]=[C:12]=[O:13])[CH:4]=[C:3]([O:2][CH3:1])[CH:9]=1

Participants

4

Reactant 2

HCID 6371PhosgeneHCID 663013,5-Dimethoxyaniline

Product 1

HCID 27362001-Isocyanato-3,5-dimethoxybenzeneYield 99.7%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

A mixture of 3,5-dimethoxyaniline (8.4 g) in toluene (100 ml) was dropwise added to a toluene solution containing 20 g of phosgene at 10° to 20° C. The resulting mixture was gradually heated and, after being refluxed for 30 minutes, cooled to room temperature. The solvent was removed by distillation under reduced pressure to give (3,5-dimethoxy)phenyl isocyanate (9.8 g). The thus obtained crude substance was added to a methanol solution (50 ml) containing triethylamine (1 g). The resultant mixture was allowed to stand at room temperature for 12 hours, poured into ice-water and extracted with ethyl acetate. The extract was washed with water, dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel chromatography using a mixture of benzene and tetrahydrofuran as the eluent to give methyl N-(3,5-dimethoxyphenyl)carbamate (10.2 g) in a yield of 88% (calculated from the starting 3,5-dimethoxyaniline). M.P., 64.5°-65° C.

Workup

  1. temperatureThe resulting mixture was gradually heated
  2. temperatureafter being refluxed for 30 minutes
  3. customThe solvent was removed by distillation under reduced pressure

Sources & evidence

ORD record
ord-d05770a17baf49afbe7437f8060d92cc
Source dataset
uspto-grants-1985_02
Patent number
US04501756

Reaction notes

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