Phosgene → Methyl 2-isocyanatobenzoate

HRID 1489767Notes

Reaction equation

HRID 1489767 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, 1 H, 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 1N 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-cf6a954ee2884ee697e6018681b08b0f
Source dataset
uspto-grants-1997_10
Patent number
US05679688

Reaction notes

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