Ethyl 2-aminobenzoate → Ethyl 2-isocyanatobenzoate

HRID 482009Notes

Reaction equation

HRID 482009 reaction equation
[C:1]([C:6]1[CH:12]=[CH:11][CH:10]=[CH:9][C:7]=1[NH2:8])([O:3][CH2:4][CH3:5])=[O:2].Cl[C:14](Cl)([O:16]C(=O)OC(Cl)(Cl)Cl)Cl>C1(C)C=CC=CC=1>[C:1]([C:6]1[CH:12]=[CH:11][CH:10]=[CH:9][C:7]=1[N:8]=[C:14]=[O:16])([O:3][CH2:4][CH3:5])=[O:2]

Participants

4

Reactant 2

HCID 6877Ethyl 2-aminobenzoateHCID 94429Triphosgene

Product 1

HCID 522616Ethyl 2-isocyanatobenzoate

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

2-Carboethoxy-phenylisocyanate (0.20 g, 1.0 mmol) was prepared by the reaction of 2-carboethoxyaniline and triphosgene in toluene at reflux, followed by removing the solvent in vacuo. The isocyanate and the compound resulting from Example 1B (0.24 g, 1.0 mmol) were combined in 40 mL of toluene and heated at reflux for 3 hours. The product was then partitioned between 5% NaHCO3 and hot ethyl acetate, and the organic phase was dried (K2CO3) and evaporated. The resulting product was converted to its hydrochloride salt and recrystallized from ethanol-ether to yield 0.12 g of the title compound as a white solid. 1H NMR (300 MHz, DMSO-d6) δ 7.92 (d, 1H), 7.65 (t, 1H), 7.12-7.27 (m, 2H), 7.08 (t, 1H), 6.72 (dd, 2H), 4.02 (t, 2H), 3.73 (s, 3H), 3.12-3.3 (m, 3H), 2.52-2.65 (m, 3H), 2.38-2.48 (m, 2H), 2.1-2.3 (m, 2H), 1.57-1.68 (m, 1H), 1.37-1.5 (m, 1H). Anal calcd for C23H25N3O3 ·HCl·H2O: C, 61.95; H, 6.33; N, 9.42. Found: C, 61.94; H, 6.10; N, 9.18.

Workup

  1. temperatureat reflux
  2. customby removing the solvent in vacuo
  3. temperatureheated
  4. temperatureat reflux for 3 hours
  5. customThe product was then partitioned between 5% NaHCO3 and hot ethyl acetate
  6. dry with materialthe organic phase was dried (K2CO3)
  7. customevaporated
  8. customrecrystallized from ethanol-ether

Sources & evidence

ORD record
ord-623060f8f51d41e2ab69cfd5b5d36f71
Source dataset
uspto-grants-1998_08
Patent number
US05792767

Reaction notes

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