Phosgene → Methyl 2-isocyanatobenzoate

HRID 1384085Notes

Reaction equation

HRID 1384085 reaction equation
[C:1](Cl)(Cl)=[O:2].[CH3:5][O:6][C:7](=[O:15])[C:8]1[C:9](=[CH:11][CH:12]=[CH:13][CH:14]=1)[NH2:10]>C1(C)C=CC=CC=1>[CH3:5][O:6][C:7]([C:8]1[CH:14]=[CH:13][CH:12]=[CH:11][C:9]=1[N:10]=[C:1]=[O:2])=[O:15]

Participants

4

Reactant 2

HCID 6371PhosgeneHCID 8635Methyl Anthranilate

Product 1

HCID 519494Methyl 2-isocyanatobenzoateYield 100%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Phosgene was bubbled through a solution of 10 g (66 mmol) of methylanthranilate in 15 ml of anhydrous toluene for 2 hours at reflux. Then the solvent was distilled off under reduced pressure to give 11.7 g (100%) of 2-methoxycarbonylphenylisocyanate; NMR (CDCl3) 3.89 (s, 3H, CH3); 7.0-7.63 (m, 3H, phenyl H-3,-4,-5); 8.0 (dd, 1H, phenyl H-6). This was converted to the title compound, in 34% overall yield, by condensation with an equimolar amount of 2-pyridylcarbinol followed by saponification of the resulting ester with 1 N sodium hydroxide and acidification of the reaction mixture to pH 4. The crude product was purified by crystallization from ethyl acetate; melting point=172-175° C.; NMR (DMSO-d6) 5.2 (s, 2H, methoxy CH2); 6.8-8.8 (m, 9H, aromatic, NH); 10.8 (broad s, 1H, OH).

Workup

  1. temperatureat reflux
  2. distillationThen the solvent was distilled off under reduced pressure

Sources & evidence

ORD record
ord-d96e41c16c63437c91a6b234a04cf1e2
Source dataset
uspto-grants-2001_07
Patent number
US06258806B1

Reaction notes

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