Anthranilic Acid → HCID 504659, compound

HRID 978354Notes

Reaction equation

HRID 978354 reaction equation
[C:1]([OH:10])(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[NH2:4].Cl[C:12]([O:14][CH2:15][CH3:16])=O.C>N1C=CC=CC=1.C(OCC)(=O)C>[CH2:15]([O:14][C:12]1[O:9][C:1](=[O:10])[C:2]2[CH:8]=[CH:7][CH:6]=[CH:5][C:3]=2[N:4]=1)[CH3:16]

Participants

6

Reactant 3

HCID 227Anthranilic AcidHCID 297MethaneHCID 10928Ethyl chloroformate

Product 1

HCID 504659HCID 504659, compound

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of anthranilic acid (0.1 mol., 13.71 gm) in dry pyridine (100 ml) at room temperature under anhydrous conditions was added ethyl chloroformate (4 equiv., 38.25 ml) in a dropwise manner over 15 minutes. After stirring for 2 hours, excess pyridine was removed under reduced pressure at 40° C. (bath temperature) and the residue was stirred vigorously in ice cold water (250 ml) for 15 minutes. The pale yellow powder was collected by filtration, washed with water (100 ml), and air-dried to give 18.6 gm of crude product. The crude product was treated with active charcoal (2 gm) in ethyl acetate (150 ml) to afford a white solid after removal of solvent. Recrystallization from EtOAc-ether gave 17.02 (89%) of the title compound, 2-ethoxy-4H-3,1-benzoxazin-4-one, as colorless crystals; m.p. 88°-90.5° C.; IR (KBr): νmax 1760 cm-1 (C=O), 1630 cm-1 (C=N); H'NMR (CDCl3); δ1.46 ppm (t, J=7.1 Hz, 3H,)CH2CH3), 4.53 ppm (q, J=7.1 Hz, 2H, OCH2CH3), 7.30-8.20 ppm (m, 4H, aromatic protons).

Workup

  1. customexcess pyridine was removed under reduced pressure at 40° C. (bath temperature)
  2. stirringthe residue was stirred vigorously in ice cold water (250 ml) for 15 minutes
  3. filtrationThe pale yellow powder was collected by filtration
  4. washwashed with water (100 ml)
  5. customair-dried
  6. customto give 18.6 gm of crude product
  7. customto afford a white solid
  8. customafter removal of solvent
  9. customRecrystallization from EtOAc-ether

Sources & evidence

ORD record
ord-aa2e841108974aee9efe40e730cc9d85
Source dataset
uspto-grants-1987_05
Patent number
US04665070

Reaction notes

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